Publications by authors named "Hiroko Hagiwara"

50 Publications

Ex vivo conditioning of peripheral blood mononuclear cells of diabetic patients promotes vasculogenic wound healing.

Stem Cells Transl Med 2021 Jun 18;10(6):895-909. Epub 2021 Feb 18.

Department of Plastic and Reconstructive Surgery, Juntendo University School of Medicine, Tokyo, Japan.

The quality and quantity of endothelial progenitor cells (EPCs) are impaired in patients with diabetes mellitus patients, leading to reduced tissue repair during autologous EPC therapy. This study aimed to address the limitations of the previously described serum-free Quantity and Quality Control Culture System (QQc) using CD34+ cells by investigating the therapeutic potential of a novel mononuclear cell (MNC)-QQ. MNCs were isolated from 50 mL of peripheral blood of patients with diabetes mellitus and healthy volunteers (n = 13 each) and subjected to QQc for 7 days in serum-free expansion media with VEGF, Flt-3 ligand, TPO, IL-6, and SCF. The vascular regeneration capability of MNC-QQ cells pre- or post-QQc was evaluated with an EPC colony-forming assay, FACS, EPC culture, tube formation assay, and quantitative real time PCR. For in vivo assessment, 1 × 10 pre- and post-MNC-QQc cells from diabetic donors were injected into a murine wound-healing model using Balb/c nude mice. The percentage of wound closure and angio-vasculogenesis was then assessed. This study revealed vasculogenic, anti-inflammatory, and wound-healing effects of MNC-QQ therapy in both in vitro and in vivo models. This system addresses the low efficiency and efficacy of the current naïve MNC therapy for wound-healing in diabetic patients. As this technique requires a simple blood draw, isolation, and peripheral blood MNC suspension culture for only a week, it can be used as a simple and effective outpatient-based vascular and regenerative therapy for patients with diabetes mellitus.
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http://dx.doi.org/10.1002/sctm.20-0309DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8133343PMC
June 2021

Unconscious and Distinctive Control of Vocal Pitch and Timbre During Altered Auditory Feedback.

Front Psychol 2020 5;11:1224. Epub 2020 Jun 5.

Department of Language Sciences, Graduate School of Humanities, Tokyo Metropolitan University, Tokyo, Japan.

Vocal control plays a critical role in smooth social communication. Speakers constantly monitor auditory feedback (AF) and make adjustments when their voices deviate from their intentions. Previous studies have shown that when certain acoustic features of the AF are artificially altered, speakers compensate for this alteration in the opposite direction. However, little is known about how the vocal control system implements compensations for alterations of different acoustic features, and associates them with subjective consciousness. The present study investigated whether compensations for the fundamental frequency (F0), which corresponds to perceived pitch, and formants, which contribute to perceived timbre, can be performed unconsciously and independently. Forty native Japanese speakers received two types of altered AF during vowel production that involved shifts of either only the formant frequencies (formant modification; Fm) or both the pitch and formant frequencies (pitch + formant modification; PFm). For each type, three levels of shift (slight, medium, and severe) in both directions (increase or decrease) were used. After the experiment, participants were tested for whether they had perceived a change in the F0 and/or formants. The results showed that (i) only formants were compensated for in the Fm condition, while both the F0 and formants were compensated for in the PFm condition; (ii) the F0 compensation exhibited greater precision than the formant compensation in PFm; and (iii) compensation occurred even when participants misperceived or could not explicitly perceive the alteration in AF. These findings indicate that non-experts can compensate for both formant and F0 modifications in the AF during vocal production, even when the modifications are not explicitly or correctly perceived, which provides further evidence for a dissociation between conscious perception and action in vocal control. We propose that such unconscious control of voice production may enhance rapid adaptation to changing speech environments and facilitate mutual communication.
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http://dx.doi.org/10.3389/fpsyg.2020.01224DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7294928PMC
June 2020

Keloid patients have higher peripheral blood endothelial progenitor cell counts and CD34 cells with normal vasculogenic and angiogenic function that overexpress vascular endothelial growth factor and interleukin-8.

Int J Dermatol 2019 Dec 9;58(12):1398-1405. Epub 2019 Jul 9.

Department of Plastic, Reconstructive and Aesthetic Surgery, Nippon Medical School, Tokyo, Japan.

Background: One suggested reason for aberrant wound healing in keloid scars is chronic inflammation of the dermis. We hypothesized that excessive blood vessel formation and high capillary density in keloid tissue is caused by dysfunction of endothelial progenitor cells.

Methods: We compared the number of circulating endothelial progenitor cells and vasculogenic and angiogenic capacity, as well as secretory function, of circulating CD34 cells in keloid patients and healthy individuals.

Results: Compared to mononuclear cell cultures from healthy donors, cultures of peripheral blood mononuclear cells obtained from keloid patients showed a more than twofold increase in the number of peripheral blood EPCs (fibronectin-adhering cells that phagocytized acetylated low-density lipoprotein and bound Ulex europaeus agglutinin-I lectin). However, there was no difference in colony-forming ability and participation in in vitro angiogenesis between circulating CD34 cells isolated from keloid patients and healthy individuals. This means that circulating CD34 /endothelial progenitor cells in keloid patients have normal vasculogenic and angiogenic function. However, CD34 cells derived from keloid patients demonstrated a more than sevenfold expression of the interleukin-8 gene and a more than fivefold expression of the vascular endothelial growth factor gene than CD34 cells derived from healthy individuals.

Conclusions: These results support the role of vascular endothelial growth factor and interleukin-8 in increased recruitment of endothelial progenitor cells in keloid patients.
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http://dx.doi.org/10.1111/ijd.14575DOI Listing
December 2019

Quality and Quantity-Cultured Murine Endothelial Progenitor Cells Increase Vascularization and Decrease Fibrosis in the Fat Graft.

Plast Reconstr Surg 2019 Apr;143(4):744e-755e

From the Plastic and Reconstructive Surgery Department, Juntendo University School of Medicine; and the Plastic and Reconstructive Surgery Department, Universitair Ziekenhuis Brussel (University Hospital Brussels), Vrije Universiteit Brussel.

Background: Fat grafting has become a valuable technique for soft-tissue reconstruction; however, long-lasting success depends on several determinants. An early blood supply to the transplanted adipocytes is important to prevent ischemia. The recently developed quality and quantity (QQ) culture increases the vasculogenic potential of endothelial progenitor cells. The authors used a murine fat grafting model to address the hypothesis that QQ-cultured endothelial progenitor cells stimulate the establishment of a blood vessel network and increase graft success.

Methods: c-KitSca-1Lin (KSL) cells were isolated as endothelial progenitor cell precursors from C57BL/6 mice. Adipose tissue was grafted with QQ-cultured KSL cells (QQKSL group), uncultured KSL cells (KSL group), adipose-derived stem cells (ASC group), and a combination (QQKSL+ASC group), and compared to a control group. Five and 10 weeks later, grafts were weighed, histologic and immunohistochemical parameters were evaluated, and gene expression was quantified by quantitative polymerase chain reaction.

Results: The highest vessel density was observed in the combined QQKSL+ASC group (68.0 ± 4.3/mm; p < 0.001) and the QQKSL group (53.9 ± 3.0/mm; p < 0.001). QQKSL cells were engrafted in proximity to the graft vasculature. QQKSL cells decreased the fibrosis percentage (13.8 ± 1.8 percent; p < 0.05). The combined QQKSL+ASC group (22.4 ± 1.8/mm; p < 0.001) showed the fewest local inflammation units. A significant up-regulation of platelet-derived growth factor and adiponectin expression was observed in the QQKSL group and QQKSL+ASC group. Graft weight persistence was not significantly different between groups.

Conclusions: Supplementing fat grafts with quality and quantity-cultured endothelial progenitor cells improves graft quality by stimulating vascularization. The increased vessel density is associated with less fibrosis, less inflammation, and better adipose tissue integrity. Enriching fat grafts with QQ-cultured endothelial progenitor cells is a potential solution to their clinical shortcomings.
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http://dx.doi.org/10.1097/PRS.0000000000005439DOI Listing
April 2019

Effectiveness of endothelial progenitor cell culture under microgravity for improved angiogenic potential.

Sci Rep 2018 09 24;8(1):14239. Epub 2018 Sep 24.

Department of Plastic and Reconstructive Surgery, School of Medicine, Juntendo University, Tokyo, Japan.

Endothelial progenitor cell (EPC) transplantation is beneficial for ischemic diseases such as critical limb ischemia and ischemic heart disease. The scarcity of functional EPCs in adults is a limiting factor for EPC transplantation therapy. The quality and quantity culture (QQc) system is an effective ex vivo method for enhancing the number and angiogenic potential of EPCs. Further, microgravity environments have been shown to enhance the functional potential of stem cells. We therefore hypothesized that cells cultured with QQc under microgravity may have enhanced functionality. We cultured human peripheral blood mononuclear cells using QQc under normal (E), microgravity (MG), or microgravity followed by normal (ME) conditions and found that ME resulted in the most significant increase in CD34+ and double positive Dil-Ac-LDL-FITC-Ulex-Lectin cells, both EPC markers. Furthermore, angiogenic potential was determined by an EPC-colony forming assay. While numbers of primitive EPC-colony forming units (pEPC-CFU) did not change, numbers of definitive EPC-CFU colonies increased most under ME conditions. Gene-expression profiling also identified increases in angiogenic factors, including vascular endothelial growth factor, under MG and ME conditions. Thus, QQc along with ME conditions could be an efficient system for significantly enhancing the number and angiogenic potential of EPCs.
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http://dx.doi.org/10.1038/s41598-018-32073-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6155294PMC
September 2018

Carboxymethylation of CRMP2 is associated with decreased Schwann cell myelination efficiency.

Neurosci Res 2019 Feb 5;139:58-62. Epub 2018 Sep 5.

Department of Peripheral Nervous System Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan. Electronic address:

Pyridoxal, an active form of vitamin B6, is known to inhibit formation of advanced glycation end-products and protect tissues from diabetic complications. Here we identified that pyridoxal is a required component for establishing Schwann cell myelination in our Schwann cell-dorsal root ganglion neuron co-culture system. When the co-culture was maintained without pyridoxal, carboxymethylation of collapsin response mediator protein 2 (CRMP2) became detectable. Carboxymethylation decreased the affinity of CRMP2 to bind with microtubules, indicating that carboxymethylation affected CRMP2 function. These results suggest that carboxymethylation of CRMP2 may be an indicator of dysfunction caused by glycation which is observed in pathological conditions, including diabetic neuropathy.
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http://dx.doi.org/10.1016/j.neures.2018.08.015DOI Listing
February 2019

Quality-Quantity Control Culture Enhances Vasculogenesis and Wound Healing Efficacy of Human Diabetic Peripheral Blood CD34+ Cells.

Stem Cells Transl Med 2018 05 24;7(5):428-438. Epub 2018 Mar 24.

Department of Basic Clinical Science, Division of Regenerative Medicine, Tokai University School of Medicine, Isehara, Japan.

Autologous endothelial progenitor cell (EPC) therapy is commonly used to stimulate angiogenesis in ischemic repair and wound healing. However, low total numbers and functional deficits of EPCs make autologous EPC therapy ineffective in diabetes. Currently, no known ex vivo culture techniques can expand and/or ameliorate the functional deficits of EPCs for clinical usage. Recently, we showed that a quality-quantity culture (QQc) system restores the vasculogenic and wound-healing efficacy of murine diabetic EPCs. To validate these results and elucidate the mechanism in a translational study, we evaluated the efficacy of this QQc system to restore the vasculogenic potential of diabetic human peripheral blood (PB) CD34+ cells. CD34+ cells purified from PB of diabetic and healthy patients were subjected to QQc. Gene expression, vascular regeneration, and expression of cytokines and paracrine mediators were analyzed. Pre- or post-QQc diabetic human PB-CD34+ cells were transplanted into wounded BALB/c nude mice and streptozotocin-induced diabetic mice to assess functional efficacy. Post-QQc diabetic human PB-CD34+ cell therapy significantly accelerated wound closure, re-epithelialization, and angiogenesis. The higher therapeutic efficacy of post-QQc diabetic human PB-CD34+ cells was attributed to increased differentiation ability of diabetic CD34+ cells, direct vasculogenesis, and enhanced expression of angiogenic factors and wound-healing genes. Thus, QQc can significantly enhance the therapeutic efficacy of human PB-CD34+ cells in diabetic wounds, overcoming the inherent limitation of autologous cell therapy in diabetic patients, and could be useful for treatment of not only wounds but also other ischemic diseases. Stem Cells Translational Medicine 2018;7:428-438.
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http://dx.doi.org/10.1002/sctm.17-0043DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5905232PMC
May 2018

Explicit Performance in Girls and Implicit Processing in Boys: A Simultaneous fNIRS-ERP Study on Second Language Syntactic Learning in Young Adolescents.

Front Hum Neurosci 2018 8;12:62. Epub 2018 Mar 8.

Department of Language Sciences, Graduate School of Humanities, Tokyo Metropolitan University, Tokyo, Japan.

Learning a second language (L2) proceeds with individual approaches to proficiency in the language. Individual differences including sex, as well as working memory (WM) function appear to have strong effects on behavioral performance and cortical responses in L2 processing. Thus, by considering sex and WM capacity, we examined neural responses during L2 sentence processing as a function of L2 proficiency in young adolescents. In behavioral tests, girls significantly outperformed boys in L2 tests assessing proficiency and grammatical knowledge, and in a reading span test (RST) assessing WM capacity. Girls, but not boys, showed significant correlations between L2 tests and RST scores. Using functional near-infrared spectroscopy (fNIRS) and event-related potential (ERP) simultaneously, we measured cortical responses while participants listened to syntactically correct and incorrect sentences. ERP data revealed a grammaticality effect only in boys in the early time window (100-300 ms), implicated in phrase structure processing. In fNIRS data, while boys had significantly increased activation in the left prefrontal region implicated in syntactic processing, girls had increased activation in the posterior language-related region involved in phonology, semantics, and sentence processing with proficiency. Presumably, boys implicitly focused on rule-based syntactic processing, whereas girls made full use of linguistic knowledge and WM function. The present results provide important fundamental data for learning and teaching in L2 education.
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http://dx.doi.org/10.3389/fnhum.2018.00062DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5853835PMC
March 2018

Short-term fasting decreases excitatory synaptic inputs to ventromedial tuberoinfundibular dopaminergic neurons and attenuates their activity in male mice.

Neurosci Lett 2018 04 10;671:70-75. Epub 2018 Feb 10.

Department of Physiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki City, 216-8511, Japan.

Tuberoinfundibular dopaminergic (TIDA) neurons in the arcuate nucleus (ARC) of the hypothalamus play a role in inhibiting prolactin (PRL) secretion from the anterior pituitary. PRL is involved in a variety of behaviors, including feeding. Consequently, we hypothesized that fasting might reduce the activity of TIDA neurons, which might alter PRL secretion. However, direct examinations of TIDA neuron activity are difficult. Recently, transgenic mice were generated that expressed green fluorescent protein (GFP) under the control of the rat tyrosine hydroxylase gene. We first determined that GFP in the dorsomedial ARC was a reliable marker of TIDA neurons. Then, we performed electrophysiology and immunocytochemistry in GFP-labeled TIDA neurons to examine whether different feeding conditions could change their activity. Eight-week-old male mice were fed or fasted for 24 h. After sacrifice, we prepared acutely isolated brain slices for conducting whole-cell voltage-clamp recordings. TIDA neurons were identified with fluorescence microscopy. The mean amplitude of miniature excitatory postsynaptic currents (mEPSCs) was significantly reduced in fasting mice compared to fed mice, but different feeding conditions did not affect the mean mEPSC intervals. This result suggested that fasting reduced the number of excitatory synaptic inputs to TIDA neurons. To determine whether a reduction in excitatory synaptic inputs would cause a reduction in TIDA neuron activity, we examined the effect of 24-h fasting on c-Fos expression in the ARC. We found that fasting significantly reduced the number of Fos-positive TIDA neurons. In addition, serum PRL levels were significantly increased. Taken together, the present findings suggested that short-term fasting attenuated TIDA neuron activity.
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http://dx.doi.org/10.1016/j.neulet.2018.02.017DOI Listing
April 2018

Age-Dependent Effects of Catechol-O-Methyltransferase (COMT) Gene Val158Met Polymorphism on Language Function in Developing Children.

Cereb Cortex 2017 01;27(1):104-116

Department of Language Sciences, Graduate School of Humanities, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan.

The genetic basis controlling language development remains elusive. Previous studies of the catechol-O-methyltransferase (COMT) Val158Met genotype and cognition have focused on prefrontally guided executive functions involving dopamine. However, COMT may further influence posterior cortical regions implicated in language perception. We investigated whether COMT influences language ability and cortical language processing involving the posterior language regions in 246 children aged 6-10 years. We assessed language ability using a language test and cortical responses recorded during language processing using a word repetition task and functional near-infrared spectroscopy. The COMT genotype had significant effects on language performance and processing. Importantly, Met carriers outperformed Val homozygotes in language ability during the early elementary school years (6-8 years), whereas Val homozygotes exhibited significant language development during the later elementary school years. Both genotype groups exhibited equal language performance at approximately 10 years of age. Val homozygotes exhibited significantly less cortical activation compared with Met carriers during word processing, particularly at older ages. These findings regarding dopamine transmission efficacy may be explained by a hypothetical inverted U-shaped curve. Our findings indicate that the effects of the COMT genotype on language ability and cortical language processing may change in a narrow age window of 6-10 years.
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http://dx.doi.org/10.1093/cercor/bhw371DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6044402PMC
January 2017

Grammatical markers switch roles and elicit different electrophysiological responses under shallow and deep semantic requirements.

Heliyon 2016 Oct 17;2(10):e00180. Epub 2016 Oct 17.

Department of Humanity and Literatures, Faculty of Letters, Tokyo Metropolitan University, Hachioji, Tokyo, Japan; Department of Language Sciences, Graduate School of Humanities, Tokyo Metropolitan University, Hachioji, Tokyo, Japan.

Static knowledge about the grammar of a natural language is represented in the cortico-subcortical system. However, the differences in dynamic verbal processing under different cognitive conditions are unclear. To clarify this, we conducted an electrophysiological experiment involving a semantic priming paradigm in which semantically congruent or incongruent word sequences (prime nouns-target verbs) were randomly presented. We examined the event-related brain potentials that occurred in response to congruent and incongruent target words that were preceded by primes with or without grammatical case markers. The two participant groups performed either the shallow (lexical judgment) or deep (direct semantic judgment) semantic tasks. We hypothesized that, irrespective of the case markers, the congruent targets would reduce centro-posterior N400 activities under the deep semantic condition, which induces selective attention to the semantic relatedness of content words. However, the same congruent targets with correct case markers would reduce lateralized negativity under the shallow semantic condition because grammatical case markers are related to automatic structural integration under semantically unattended conditions. We observed that congruent targets (e.g., 'open') that were preceded by primes with congruent case markers (e.g., 'shutter-object case') reduced lateralized negativity under the shallow semantic condition. In contrast, congruent targets, irrespective of case markers, consistently yielded N400 reductions under the deep semantic condition. To summarize, human neural verbal processing differed in response to the same grammatical markers in the same verbal expressions under semantically attended or unattended conditions.
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http://dx.doi.org/10.1016/j.heliyon.2016.e00180DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5071545PMC
October 2016

Effects of sex and proficiency in second language processing as revealed by a large-scale fNIRS study of school-aged children.

Hum Brain Mapp 2015 Oct 3;36(10):3890-911. Epub 2015 Jul 3.

Department of Language Sciences, Graduate School of Humanities, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan.

Previous neuroimaging studies in adults have revealed that first and second languages (L1/L2) share similar neural substrates, and that proficiency is a major determinant of the neural organization of L2 in the lexical-semantic and syntactic domains. However, little is known about neural substrates of children in the phonological domain, or about sex differences. Here, we conducted a large-scale study (n = 484) of school-aged children using functional near-infrared spectroscopy and a word repetition task, which requires a great extent of phonological processing. We investigated cortical activation during word processing, emphasizing sex differences, to clarify similarities and differences between L1 and L2, and proficiency-related differences during early L2 learning. L1 and L2 shared similar neural substrates with decreased activation in L2 compared to L1 in the posterior superior/middle temporal and angular/supramarginal gyri for both sexes. Significant sex differences were found in cortical activation within language areas during high-frequency word but not during low-frequency word processing. During high-frequency word processing, widely distributed areas including the angular/supramarginal gyri were activated in boys, while more restricted areas, excluding the angular/supramarginal gyri were activated in girls. Significant sex differences were also found in L2 proficiency-related activation: activation significantly increased with proficiency in boys, whereas no proficiency-related differences were found in girls. Importantly, cortical sex differences emerged with proficiency. Based on previous research, the present results indicate that sex differences are acquired or enlarged during language development through different cognitive strategies between sexes, possibly reflecting their different memory functions.
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http://dx.doi.org/10.1002/hbm.22885DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6868995PMC
October 2015

Hybrid De Novo Genome Assembly Using MiSeq and SOLiD Short Read Data.

PLoS One 2015 28;10(4):e0126289. Epub 2015 Apr 28.

Computational Biology Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, Japan.

A hybrid de novo assembly pipeline was constructed to utilize both MiSeq and SOLiD short read data in combination in the assembly. The short read data were converted to a standard format of the pipeline, and were supplied to the pipeline components such as ABySS and SOAPdenovo. The assembly pipeline proceeded through several stages, and either MiSeq paired-end data, SOLiD mate-paired data, or both of them could be specified as input data at each stage separately. The pipeline was examined on the filamentous fungus Aspergillus oryzae RIB40, by aligning the assembly results against the reference sequences. Using both the MiSeq and the SOLiD data in the hybrid assembly, the alignment length was improved by a factor of 3 to 8, compared with the assemblies using either one of the data types. The number of the reproduced gene cluster regions encoding secondary metabolite biosyntheses (SMB) was also improved by the hybrid assemblies. These results imply that the MiSeq data with long read length are essential to construct accurate nucleotide sequences, while the SOLiD mate-paired reads with long insertion length enhance long-range arrangements of the sequences. The pipeline was also tested on the actinomycete Streptomyces avermitilis MA-4680, whose gene is known to have high-GC content. Although the quality of the SOLiD reads was too low to perform any meaningful assemblies by themselves, the alignment length to the reference was improved by a factor of 2, compared with the assembly using only the MiSeq data.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0126289PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4412624PMC
April 2016

Sex differences in feeding behavior in rats: the relationship with neuronal activation in the hypothalamus.

Front Neurosci 2015 30;9:88. Epub 2015 Mar 30.

Department of Physiology, St. Marianna University School of Medicine Kawasaki, Japan ; Department of Physiology, Yokohama City University Graduate School of Medicine Yokohama, Japan.

There is general agreement that the central nervous system in rodents differs between sexes due to the presence of gonadal steroid hormone during differentiation. Sex differences in feeding seem to occur among species, and responses to fasting (i.e., starvation), gonadal steroids (i.e., testosterone and estradiol), and diet (i.e., western-style diet) vary significantly between sexes. The hypothalamus is the center for controlling feeding behavior. We examined the activation of feeding-related peptides in neurons in the hypothalamus. Phosphorylation of cyclic AMP response element-binding protein (CREB) is a good marker for neural activation, as is the Fos antigen. Therefore, we predicted that sex differences in the activity of melanin-concentrating hormone (MCH) neurons would be associated with feeding behavior. We determined the response of MCH neurons to glucose in the lateral hypothalamic area (LHA) and our results suggested MCH neurons play an important role in sex differences in feeding behavior. In addition, fasting increased the number of orexin neurons harboring phosphorylated CREB in female rats (regardless of the estrous day), but not male rats. Glucose injection decreased the number of these neurons with phosphorylated CREB in fasted female rats. Finally, under normal spontaneous food intake, MCH neurons, but not orexin neurons, expressed phosphorylated CREB. These sex differences in response to fasting and glucose, as well as under normal conditions, suggest a vulnerability to metabolic challenges in females.
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http://dx.doi.org/10.3389/fnins.2015.00088DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4378303PMC
April 2015

Expression of phosphorylated cyclic AMP response element-binding protein in melanin-concentrating hormone neurons and orexin neurons in male and female rats during ad-libitum feeding.

Neuroreport 2014 Jul;25(10):766-70

aDepartment of Physiology, Yokohama City University Graduate School of Medicine, Yokohama bDepartment of Physiology, St. Marianna University School of Medicine, Kawasaki, Japan.

Using phosphorylated cyclic AMP response element-binding protein (pCREB) as a marker of neural activity, we previously suggested that orexin neurons and melanin-concentrating hormone (MCH) neurons play distinct roles in feeding behavior. In the present study, we examined the expression of pCREB during ad-libitum feeding; previously, only fasted animals were examined. MCH neurons, but not orexin neurons, expressed pCREB during spontaneous food intake. The induction of pCREB expression did not differ by sex, but attenuation seemed to occur faster in females than in males. On the basis of the results of the present study, we speculate that MCH neurons respond to nutrition-related feeding, but the feeding-related activity of orexin was not evident unless hunger was accompanied by stress, such as the stress caused by the absence of food in the case of fasting. Therefore, the desire to eat under normal conditions does not drive orexin neurons, but it does drive MCH neurons. We tested this hypothesis by examining the effects of consuming glucose or saccharin, a nonmetabolized sweetener, in fasted male and female rats. Glucose and saccharin were equally effective in reducing pCREB expression in the orexin neurons of female rats. In MCH neurons, glucose attenuated the expression of pCREB, but saccharin had no effect, irrespective of sex. Taken together, the results indicate that MCH and orexin peptides play physiologically distinct roles in feeding behavior.
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http://dx.doi.org/10.1097/WNR.0000000000000172DOI Listing
July 2014

Genetic diversity of feline morbilliviruses isolated in Japan.

J Gen Virol 2014 Jul 11;95(Pt 7):1464-1468. Epub 2014 Apr 11.

Laboratory of Signal Transduction, Department of Cell Biology, Institute for Virus Research, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan.

Feline morbillivirus (FmoPV) is an emerging virus in domestic cats and considered to be associated with tubulointerstitial nephritis. Although FmoPV was first described in China in 2012, there has been no report of the isolation of this virus in other countries. In this report, we describe the isolation and characterization of FmoPV from domestic cats in Japan. By using reverse transcription (RT)-PCR, we found that three of 13 urine samples from cats brought to veterinary hospitals were positive for FmoPV. FmoPV strains SS1 to SS3 were isolated from the RT-PCR-positive urine samples. Crandell-Rees feline kidney (CRFK) cells exposed to FmoPV showed cytopathic effects with syncytia formation, and FmoPV N protein was detected by indirect immunofluorescence assays. In addition, pleomorphic virus particles with apparent glycoprotein envelope spikes were observed by electron microscopy. By sequence analysis of FmoPV H and L genes, we found that FmoPVs showed genetic diversity; however, signatures of positive selection were not identified.
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http://dx.doi.org/10.1099/vir.0.065029-0DOI Listing
July 2014

Genome and transcriptome analysis of the basidiomycetous yeast Pseudozyma antarctica producing extracellular glycolipids, mannosylerythritol lipids.

PLoS One 2014 24;9(2):e86490. Epub 2014 Feb 24.

Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5-2, 1-1-1 Higashi, Tsukuba, Ibaraki, Japan.

Pseudozyma antarctica is a non-pathogenic phyllosphere yeast known as an excellent producer of mannosylerythritol lipids (MELs), multi-functional extracellular glycolipids, from vegetable oils. To clarify the genetic characteristics of P. antarctica, we analyzed the 18 Mb genome of P. antarctica T-34. On the basis of KOG analysis, the number of genes (219 genes) categorized into lipid transport and metabolism classification in P. antarctica was one and a half times larger than that of yeast Saccharomyces cerevisiae (140 genes). The gene encoding an ATP/citrate lyase (ACL) related to acetyl-CoA synthesis conserved in oleaginous strains was found in P. antarctica genome: the single ACL gene possesses the four domains identical to that of the human gene, whereas the other oleaginous ascomycetous species have the two genes covering the four domains. P. antarctica genome exhibited a remarkable degree of synteny to U. maydis genome, however, the comparison of the gene expression profiles under the culture on the two carbon sources, glucose and soybean oil, by the DNA microarray method revealed that transcriptomes between the two species were significantly different. In P. antarctica, expression of the gene sets relating fatty acid metabolism were markedly up-regulated under the oily conditions compared with glucose. Additionally, MEL biosynthesis cluster of P. antarctica was highly expressed regardless of the carbon source as compared to U. maydis. These results strongly indicate that P. antarctica has an oleaginous nature which is relevant to its non-pathogenic and MEL-overproducing characteristics. The analysis and dataset contribute to stimulate the development of improved strains with customized properties for high yield production of functional bio-based materials.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0086490PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3933340PMC
December 2014

Acoustic cues for the recognition of self-voice and other-voice.

Front Psychol 2013 11;4:735. Epub 2013 Oct 11.

Department of Language Sciences, Graduate School of Humanities, Tokyo Metropolitan University Tokyo, Japan.

Self-recognition, being indispensable for successful social communication, has become a major focus in current social neuroscience. The physical aspects of the self are most typically manifested in the face and voice. Compared with the wealth of studies on self-face recognition, self-voice recognition (SVR) has not gained much attention. Converging evidence has suggested that the fundamental frequency (F0) and formant structures serve as the key acoustic cues for other-voice recognition (OVR). However, little is known about which, and how, acoustic cues are utilized for SVR as opposed to OVR. To address this question, we independently manipulated the F0 and formant information of recorded voices and investigated their contributions to SVR and OVR. Japanese participants were presented with recorded vocal stimuli and were asked to identify the speaker-either themselves or one of their peers. Six groups of 5 peers of the same sex participated in the study. Under conditions where the formant information was fully preserved and where only the frequencies lower than the third formant (F3) were retained, accuracies of SVR deteriorated significantly with the modulation of the F0, and the results were comparable for OVR. By contrast, under a condition where only the frequencies higher than F3 were retained, the accuracy of SVR was significantly higher than that of OVR throughout the range of F0 modulations, and the F0 scarcely affected the accuracies of SVR and OVR. Our results indicate that while both F0 and formant information are involved in SVR, as well as in OVR, the advantage of SVR is manifested only when major formant information for speech intelligibility is absent. These findings imply the robustness of self-voice representation, possibly by virtue of auditory familiarity and other factors such as its association with motor/articulatory representation.
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http://dx.doi.org/10.3389/fpsyg.2013.00735DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3795466PMC
October 2013

Fine de novo sequencing of a fungal genome using only SOLiD short read data: verification on Aspergillus oryzae RIB40.

PLoS One 2013 7;8(5):e63673. Epub 2013 May 7.

National Institute of Advanced Industrial Science and Technology (AIST), Sapporo, Hokkaido, Japan.

The development of next-generation sequencing (NGS) technologies has dramatically increased the throughput, speed, and efficiency of genome sequencing. The short read data generated from NGS platforms, such as SOLiD and Illumina, are quite useful for mapping analysis. However, the SOLiD read data with lengths of <60 bp have been considered to be too short for de novo genome sequencing. Here, to investigate whether de novo sequencing of fungal genomes is possible using only SOLiD short read sequence data, we performed de novo assembly of the Aspergillus oryzae RIB40 genome using only SOLiD read data of 50 bp generated from mate-paired libraries with 2.8- or 1.9-kb insert sizes. The assembled scaffolds showed an N50 value of 1.6 Mb, a 22-fold increase than those obtained using only SOLiD short read in other published reports. In addition, almost 99% of the reference genome was accurately aligned by the assembled scaffold fragments in long lengths. The sequences of secondary metabolite biosynthetic genes and clusters, whose products are of considerable interest in fungal studies due to their potential medicinal, agricultural, and cosmetic properties, were also highly reconstructed in the assembled scaffolds. Based on these findings, we concluded that de novo genome sequencing using only SOLiD short reads is feasible and practical for molecular biological study of fungi. We also investigated the effect of filtering low quality data, library insert size, and k-mer size on the assembly performance, and recommend for the assembly use of mild filtered read data where the N50 was not so degraded and the library has an insert size of ∼2.0 kb, and k-mer size 33.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0063673PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3646829PMC
December 2013

Neonatal disruption of serine racemase causes schizophrenia-like behavioral abnormalities in adulthood: clinical rescue by d-serine.

PLoS One 2013 22;8(4):e62438. Epub 2013 Apr 22.

Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba, Japan.

Background: D-Serine, an endogenous co-agonist of the N-methyl-D-aspartate (NMDA) receptor, is synthesized from L-serine by serine racemase (SRR). Given the role of D-serine in both neurodevelopment and the pathophysiology of schizophrenia, we examined whether neonatal disruption of D-serine synthesis by SRR inhibition could induce behavioral abnormalities relevant to schizophrenia, in later life.

Methodology/principal Findings: Neonatal mice (7-9 days) were injected with vehicle or phenazine methosulfate (Met-Phen: 3 mg/kg/day), an SRR inhibitor. Behavioral evaluations, such as spontaneous locomotion, novel object recognition test (NORT), and prepulse inhibition (PPI) were performed at juvenile (5-6 weeks old) and adult (10-12 weeks old) stages. In addition, we tested the effects of D-serine on PPI deficits in adult mice after neonatal Met-Phen exposure. Finally, we assessed whether D-serine could prevent the onset of schizophrenia-like behavior in these mice. Neonatal Met-Phen treatment reduced D-serine levels in the brain, 24 hours after the final dose. Additionally, this treatment caused behavioral abnormalities relevant to prodromal symptoms in juveniles and to schizophrenia in adults. A single dose of D-serine improved PPI deficits in adult mice. Interestingly, chronic administration of D-serine (900 mg/kg/day from P35 to P70) significantly prevented the onset of PPI deficits after neonatal Met-Phen exposure.

Conclusions/significance: This study shows that disruption of D-serine synthesis during developmental stages leads to behavioral abnormalities relevant to prodromal symptoms and schizophrenia, in later life. Furthermore, early pharmacological intervention with D-serine may prevent the onset of psychosis in adult.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0062438PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3632541PMC
November 2013

Genome Sequence of the Basidiomycetous Yeast Pseudozyma antarctica T-34, a Producer of the Glycolipid Biosurfactants Mannosylerythritol Lipids.

Genome Announc 2013 Apr 4;1(2):e0006413. Epub 2013 Apr 4.

Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Tsukuba, Ibaraki, Japan.

The basidiomycetous yeast Pseudozyma antarctica T-34 is an excellent producer of mannosylerythritol lipids (MELs), members of the multifunctional extracellular glycolipids, from various feedstocks. Here, the genome sequence of P. antarctica T-34 was determined and annotated. Analysis of the sequence might provide insights into the properties of this yeast that make it superior for use in the production of functional glycolipids, leading to the further development of P. antarctica for industrial applications.
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http://dx.doi.org/10.1128/genomeA.00064-13DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3622993PMC
April 2013

Semantic categories and contexts of written words affect the early ERP component.

Neuroreport 2013 Apr;24(6):292-7

Department of Language Sciences, Tokyo Metropolitan University, Tokyo, Japan.

We investigated the spatiotemporal patterns of event-related potentials to examine how semantic categories affect early stages of written word processing in the brain. We used a semantic priming paradigm in which the categories of prime and target words were the same (animate or inanimate). Event-related potentials were recorded while native Japanese participants made semantic-relatedness judgments of word pairs. Semantic category effects were observed approximately 150 ms after the target item was presented. Inanimate words elicited greater positive deflection than animate words, but no significant difference was observed for prime item processing. Source modeling estimated that the observed effects were induced by neural mechanisms occurring in the anterior temporal region, the posterior portion of the inferior temporal region, and the inferior parietal regions in both the hemispheres. Our results suggest that semantic category effects in the early stages of word processing are evoked by multiple cortical regions related to top-down processing of the preceding semantic information.
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http://dx.doi.org/10.1097/WNR.0b013e32835f679dDOI Listing
April 2013

Sex-specific differences in pain response by dopamine in the bed nucleus of the stria terminalis in rats.

Neuroreport 2013 Mar;24(4):181-5

Department of Physiology, St Marianna University School of Medicine, Kawasaki, Japan.

The formalin test for nociception shows characteristic sex differences in the pain response during the interphase period of the test. However, the mechanism underlying these differences remains unclear. We have recently reported the sex-specific involvement of the lateral subdivision of the bed nucleus of the stria terminalis (BSTL) in the formalin test in rats. Here, we evaluated whether sex-specific differences in the pain response were modulated by the dopamine system in the BSTL. We first examined the effects of injecting a dopamine D1 receptor agonist, dihydrexidine, or antagonist, SCH23390, into the BSTL on the formalin test. During the interphase of the formalin test, injection of the D1 receptor agonist exerted no effect in male or female rats. The antagonist significantly enhanced the nociceptive response in female rats but not in males, indicating a sex difference in the involvement of the dopamine system in the formalin test. Next, we examined the expression of dopamine D1 receptors in the BSTL. Immunohistochemical analysis showed that the dopamine D1 receptor was expressed in the BSTL in both sexes but showed stronger immunoreactivity in male rats than in females. These results suggest sex-specific differences in the formalin test in which the response of dopamine neurons projecting to the BSTL plays a role in attenuating pain in female rats.
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http://dx.doi.org/10.1097/WNR.0b013e32835d8540DOI Listing
March 2013

Effect of second language exposure on brain activity for language processing among preschoolers.

Neurosci Res 2012 May 24;73(1):73-9. Epub 2012 Feb 24.

Department of Psychology, Graduate School of Arts and Letters, Tohoku University, Japan.

We investigated brain activity in 3-5-year-old preschoolers as they listened to connected speech stimuli in Japanese (first language), English (second language), and Chinese (a rarely exposed, foreign language) using near-infrared spectroscopy. Unlike the younger preschoolers who had been exposed to English for almost 1 year, brain activity in the bilateral frontal regions of the older preschoolers who had been exposed to English for almost 2 years was higher for Japanese and English speech stimuli than for Chinese. This tendency seemed to be similar to that observed in adults who had learned English for some years. These results indicate that exposure to a second language affects brain activity to language stimuli among preschoolers.
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http://dx.doi.org/10.1016/j.neures.2012.02.004DOI Listing
May 2012

Semantic relatedness between words in each individual brain: an event-related potential study.

Neurosci Lett 2011 Aug 29;501(2):72-7. Epub 2011 Jun 29.

Department of Language Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan.

The relationship between 2 words is judged by the meanings of words. Here, we examined how the semantic relatedness of words is structured in each individual brain. During measurements of event-related potentials (ERPs), participants performed semantic-relatedness judgments of word pairs. For each participant, we divided word pairs into 2 groups--related and unrelated pairs--and compared their ERPs. All of the participants showed a significant N400 effect. However, when we applied an identical grouping of pairs, this effect was observed only in half the number of the participants. These results show that our single-subject analysis of N400 extracted semantic relatedness of words in the individual brain. Future studies using this analysis will clarify the organization of the mental lexicon.
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http://dx.doi.org/10.1016/j.neulet.2011.06.044DOI Listing
August 2011

Sound to language: different cortical processing for first and second languages in elementary school children as revealed by a large-scale study using fNIRS.

Cereb Cortex 2011 Oct 24;21(10):2374-93. Epub 2011 Feb 24.

Department of Language Sciences, Graduate School of Humanities, Tokyo Metropolitan University, Minami-Osawa, Hachioji, Tokyo 192-0397, Japan.

A large-scale study of 484 elementary school children (6-10 years) performing word repetition tasks in their native language (L1-Japanese) and a second language (L2-English) was conducted using functional near-infrared spectroscopy. Three factors presumably associated with cortical activation, language (L1/L2), word frequency (high/low), and hemisphere (left/right), were investigated. L1 words elicited significantly greater brain activation than L2 words, regardless of semantic knowledge, particularly in the superior/middle temporal and inferior parietal regions (angular/supramarginal gyri). The greater L1-elicited activation in these regions suggests that they are phonological loci, reflecting processes tuned to the phonology of the native language, while phonologically unfamiliar L2 words were processed like nonword auditory stimuli. The activation was bilateral in the auditory and superior/middle temporal regions. Hemispheric asymmetry was observed in the inferior frontal region (right dominant), and in the inferior parietal region with interactions: low-frequency words elicited more right-hemispheric activation (particularly in the supramarginal gyrus), while high-frequency words elicited more left-hemispheric activation (particularly in the angular gyrus). The present results reveal the strong involvement of a bilateral language network in children's brains depending more on right-hemispheric processing while acquiring unfamiliar/low-frequency words. A right-to-left shift in laterality should occur in the inferior parietal region, as lexical knowledge increases irrespective of language.
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http://dx.doi.org/10.1093/cercor/bhr023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3169662PMC
October 2011

An event-related potential investigation of lexical pitch-accent processing in auditory Japanese.

Brain Res 2011 Apr;1385:217-28

Department of Language Sciences, Graduate School of Humanities, Tokyo Metropolitan University, Tokyo, Japan.

Lexical prosody plays an important role in speech comprehension. However, the electrophysiological nature and time course of processing lexical prosody in mora-timed languages are rarely known in contrast to the wealth of knowledge in stress-timed languages and syllable-timed languages like German and French. In the present study, lexical pitch-accent processing in Japanese is investigated using event-related potentials. Participants listened to sentences with verbs either correct or incorrect with respect to pitch-accent (phonological condition), word meaning (semantic condition) or sentence type (syntactic condition). When the brain potentials of correct and incorrect sentences were compared within conditions, the phonological and semantic conditions showed a negativity and positivity (P600), while the syntactic condition displayed a P600. Furthermore, the negativity in response to pitch-accent violations (pitch-accent negativity) appeared approximately 60ms earlier than the response to semantic violations (N400), while no significant topographical distributions were found between the two components. These results suggest that the pitch-accent negativity reflects initial phonological processing followed by lexical access and word recognition. Moreover, the P600 displayed in all conditions was interpreted as a general integration process that is common across the three domains.
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http://dx.doi.org/10.1016/j.brainres.2011.02.008DOI Listing
April 2011

Age and amount of exposure to a foreign language during childhood: behavioral and ERP data on the semantic comprehension of spoken English by Japanese children.

Neurosci Res 2011 Jun 12;70(2):197-205. Epub 2011 Feb 12.

Department of Language Sciences, Graduate School of Humanities, Tokyo Metropolitan University, Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan.

Children's foreign-language (FL) learning is a matter of much social as well as scientific debate. Previous behavioral research indicates that starting language learning late in life can lead to problems in phonological processing. Inadequate phonological capacity may impede lexical learning and semantic processing (phonological bottleneck hypothesis). Using both behavioral and neuroimaging data, here we examine the effects of age of first exposure (AOFE) and total hours of exposure (HOE) to English, on 350 Japanese primary-school children's semantic processing of spoken English. Children's English proficiency scores and N400 event-related brain potentials (ERPs) were analyzed in multiple regression analyses. The results showed (1) that later, rather than earlier, AOFE led to higher English proficiency and larger N400 amplitudes, when HOE was controlled for; and (2) that longer HOE led to higher English proficiency and larger N400 amplitudes, whether AOFE was controlled for or not. These data highlight the important role of amount of exposure in FL learning, and cast doubt on the view that starting FL learning earlier always produces better results.
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http://dx.doi.org/10.1016/j.neures.2011.01.018DOI Listing
June 2011

Second-language instinct and instruction effects: nature and nurture in second-language acquisition.

J Cogn Neurosci 2011 Oct 21;23(10):2716-30. Epub 2011 Jan 21.

Miyagi Gakuin Women's University, Sendai-shi, Japan.

Adults seem to have greater difficulties than children in acquiring a second language (L2) because of the alleged "window of opportunity" around puberty. Postpuberty Japanese participants learned a new English rule with simplex sentences during one month of instruction, and then they were tested on "uninstructed complex sentences" as well as "instructed simplex sentences." The behavioral data show that they can acquire more knowledge than is instructed, suggesting the interweaving of nature (universal principles of grammar, UG) and nurture (instruction) in L2 acquisition. The comparison in the "uninstructed complex sentences" between post-instruction and pre-instruction using functional magnetic resonance imaging reveals a significant activation in Broca's area. Thus, this study provides new insight into Broca's area, where nature and nurture cooperate to produce L2 learners' rich linguistic knowledge. It also shows neural plasticity of adult L2 acquisition, arguing against a critical period hypothesis, at least in the domain of UG.
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http://dx.doi.org/10.1162/jocn.2011.21607DOI Listing
October 2011

The acceleration of spoken-word processing in children's native-language acquisition: an ERP cohort study.

Neuropsychologia 2011 Apr 12;49(5):790-799. Epub 2011 Jan 12.

Department of Language Sciences, Graduate School of Humanities, Tokyo Metropolitan University, Minami-Osawa, Hachioji, Tokyo 192-0397, Japan; Research Institute of Science and Technology for Society (RISTEX), Japan Science and Technology Agency (JST), Nibancho, Chiyoda-ku, Tokyo 100-0004, Japan. Electronic address:

Healthy adults can identify spoken words at a remarkable speed, by incrementally analyzing word-onset information. It is currently unknown how this adult-level speed of spoken-word processing emerges during children's native-language acquisition. In a picture-word mismatch paradigm, we manipulated the semantic congruency between picture contexts and spoken words, and recorded event-related potential (ERP) responses to the words. Previous similar studies focused on the N400 response, but we focused instead on the onsets of semantic congruency effects (N200 or Phonological Mismatch Negativity), which contain critical information for incremental spoken-word processing. We analyzed ERPs obtained longitudinally from two age cohorts of 40 primary-school children (total n=80) in a 3-year period. Children first tested at 7 years of age showed earlier onsets of congruency effects (by approximately 70ms) when tested 2 years later (i.e., at age 9). Children first tested at 9 years of age did not show such shortening of onset latencies 2 years later (i.e., at age 11). Overall, children's onset latencies at age 9 appeared similar to those of adults. These data challenge the previous hypothesis that word processing is well established at age 7. Instead they support the view that the acceleration of spoken-word processing continues beyond age 7.
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http://dx.doi.org/10.1016/j.neuropsychologia.2011.01.007DOI Listing
April 2011
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