Publications by authors named "Yi-Mei Yang"

32 Publications

Effects of nursing care in fast-track surgery on postoperative pain, psychological state, and patient satisfaction with nursing for glioma.

World J Clin Cases 2021 Jul;9(20):5435-5441

Department of Neurosurgery, Chongqing University Cancer Hospital, Chongqing 400030, China.

Background: The brain is the most complex organ in the human body. Treatment for a glioma always involves a multi-disciplinary team. Nursing care in fast-track surgery or enhanced recovery after surgery is such kind of work implemented by an interdisciplinary team to provide services to patients to improve their outcomes.

Aim: To explore the effects of nursing care in fast-track surgery on postoperative pain, psychological state, and patient satisfaction with nursing for glioma.

Methods: From June 2018 to June 2020, 138 patients who underwent operation for glioma at Cancer Hospital Affiliated to Chongqing University were selected. They were categorized into groups according to different nursing care that they received. Of them, 69 patients receiving nursing care in fast-track surgery were included in an experimental group, and 69 patients receiving conventional postoperative nursing were included in a control group. Visual analogue scale was used to evaluate postoperative pain in the two groups immediately after the operation and at 3 d after the operation. Self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were used to evaluate the psychological status of patients immediately after operation and on the 3 postoperative day. A self-made satisfaction scale for patient satisfaction with nursing was used to evaluate and compare patient satisfaction with nursing between the two groups.

Results: Time to excretion, time to out-of-bed activities, and length of hospital stay were significantly shorter in the observation group than in the control group ( < 0.05). There was no significant difference in duration of operative time or intraoperative bleeding between the two groups ( > 0.05). There was no significant difference in postoperative pain score between the two groups ( > 0.05). The pain score was significantly lower in the observation group than in the control group at 3 d after the operation ( < 0.05). There was no significant difference in postoperative SAS or SDS score between the two groups ( > 0.05). SAS and SDS scores were significantly lower in the observation group than in the control group at 3 d after operation ( < 0.05). The rate of patient satisfaction with nursing was 94.2% in the observation group, which was significantly higher than that (81.2%) of the control group ( < 0.05).

Conclusion: Nursing care in fast-track surgery can relieve postoperative pain, anxiety, and depression, and improve patient satisfaction with nursing in patients with glioma, which is worthy of clinical application.
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http://dx.doi.org/10.12998/wjcc.v9.i20.5435DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8281405PMC
July 2021

Developmental plasticity of NMDA receptors at the calyx of Held synapse.

Neuropharmacology 2021 Jul 6;196:108697. Epub 2021 Jul 6.

Program in Neurosciences & Mental Health, SickKids Research Institute, 555 University Ave, Toronto, Ontario M5G 1X8, Canada; Department of Physiology, University of Toronto, 1 Kings Circle, Toronto, Ontario, M5S 1A8, Canada. Electronic address:

Excitatory synaptic transmission is largely mediated by glutamate receptors in central synapses, such as the calyx of Held synapse in the auditory brainstem. This synapse is best known for undergoing extensive morphological and functional changes throughout early development and thereby has served as a prominent model system to study presynaptic mechanisms of neurotransmitter release. However, the pivotal roles of N-methyl-d-aspartate receptors (NMDARs) in gating acute forms of activity-dependent, persistent plasticity in vitro and chronic developmental remodeling in vivo are hardly noted. This article will provide a retrospective review of key experimental evidence to conceptualize the impact of a transient abundance of NMDARs during the early postnatal stage on the functionality of fast-spiking central synapses while raising a series of outstanding questions that are of general significance for understanding the developing brain in health and diseases.
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http://dx.doi.org/10.1016/j.neuropharm.2021.108697DOI Listing
July 2021

Acute intranasal dopamine application counteracts the reversal learning deficit of spontaneously hypertensive rats in an attentional set-shifting task.

Psychopharmacology (Berl) 2021 May 12. Epub 2021 May 12.

M et P Pharma AG Emmetten Switzerland and Oceanographic Center, Nova Southeastern University, Fort Lauderdale, FL, USA.

Rationale: Studies on the attention-deficit/hyperactivity disorder (ADHD) have concluded that the disorder might be caused by a deficit in the inhibitory control of executive functions because of dopamine hypofunction. Recently, the intranasal route has emerged as an effective alternative means for sending dopamine directly to the brain. However, whether the treatment can ameliorate the deficits of inhibitory control in ADHD remains unknown.

Objectives: Investigating the effects of acute intranasal dopamine (IN-DA) on the inhibitory control of executive functions of an ADHD rodent model.

Methods: We trained an animal model of ADHD, the spontaneously hypertensive rat (SHR), and Wistar rats as controls, in an attentional set-shifting task (ASST) in which dopamine (0.15 mg/kg, 0.3 mg/kg, or vehicle) was intranasally administered before the final test.

Results: IN-DA application dose-dependently improved the performance and reduced errors of SHR in the initial reversal learning. The effect size was comparable to that of a peripheral injection of 0.6 mg/kg methylphenidate. In control Wistar rats, the highest dose of intranasal dopamine (0.3 mg/kg) induced deficits in the reversal learning of extradimensional discriminations.

Conclusions: The findings suggest that the IN-DA treatment has potential for use in the treatment of ADHD; however, caution must be exercised when determining the dosage to be administered, because too much dopamine may have negative effects.
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http://dx.doi.org/10.1007/s00213-021-05863-2DOI Listing
May 2021

Functional Convergence of Motor and Social Processes in Lobule IV/V of the Mouse Cerebellum.

Cerebellum 2021 Mar 4. Epub 2021 Mar 4.

Department of Biomedical Sciences, University of Minnesota Medical School, 1035 University Drive, Duluth, MN, 55812, USA.

Topographic organization of the cerebellum is largely segregated into the anterior and posterior lobes that represent its "motor" and "non-motor" functions, respectively. Although patients with damage to the anterior cerebellum often exhibit motor deficits, it remains unclear whether and how such an injury affects cognitive and social behaviors. To address this, we perturbed the activity of major anterior lobule IV/V in mice by either neurotoxic lesion or chemogenetic excitation of Purkinje cells in the cerebellar cortex. We found that both of the manipulations impaired motor coordination, but not general locomotion or anxiety-related behavior. The lesioned animals showed memory deficits in object recognition and social-associative recognition tests, which were confounded by a lack of exploration. Chemogenetic excitation of Purkinje cells disrupted the animals' social approach in a less-preferred context and social memory, without affecting their overall exploration and object-based memory. In a free social interaction test, the two groups exhibited less interaction with a stranger conspecific. Subsequent c-Fos imaging indicated that decreased neuronal activities in the medial prefrontal cortex, hippocampal dentate gyrus, parahippocampal cortices, and basolateral amygdala, as well as disorganized modular structures of the brain networks might underlie the reduced social interaction. These findings suggest that the anterior cerebellum plays an intricate role in processing motor, cognitive, and social functions.
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http://dx.doi.org/10.1007/s12311-021-01246-7DOI Listing
March 2021

Altered dopaminergic pathways and therapeutic effects of intranasal dopamine in two distinct mouse models of autism.

Mol Brain 2020 08 10;13(1):111. Epub 2020 Aug 10.

Department of Biomedical Sciences, University of Minnesota Medical School, 1035 University Drive, Duluth, MN, 55812, USA.

The dopamine (DA) system has a profound impact on reward-motivated behavior and is critically involved in neurodevelopmental disorders, such as autism spectrum disorder (ASD). Although DA defects are found in autistic patients, it is not well defined how the DA pathways are altered in ASD and whether DA can be utilized as a potential therapeutic agent for ASD. To this end, we employed a phenotypic and a genetic ASD model, i.e., Black and Tan BRachyury TItpr3/J (BTBR) mice and Fragile X Mental Retardation 1 knockout (Fmr1-KO) mice, respectively. Immunostaining of tyrosine hydroxylase (TH) to mark dopaminergic neurons revealed an overall reduction in the TH expression in the substantia nigra, ventral tegmental area and dorsal striatum of BTBR mice, as compared to C57BL/6 J wild-type ones. In contrast, Fmr1-KO animals did not show such an alteration but displayed abnormal morphology of TH-positive axons in the striatum with higher "complexity" and lower "texture". Both strains exhibited decreased expression of striatal dopamine transporter (DAT) and increased spatial coupling between vesicular glutamate transporter 1 (VGLUT1, a label for glutamatergic terminals) and TH signals, while GABAergic neurons quantified by glutamic acid decarboxylase 67 (GAD67) remained intact. Intranasal administration of DA rescued the deficits in non-selective attention, object-based attention and social approaching of BTBR mice, likely by enhancing the level of TH in the striatum. Application of intranasal DA to Fmr1-KO animals alleviated their impairment of social novelty, in association with reduced striatal TH protein. These results suggest that although the DA system is modified differently in the two ASD models, intranasal treatment with DA effectively rectifies their behavioral phenotypes, which may present a promising therapy for diverse types of ASD.
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http://dx.doi.org/10.1186/s13041-020-00649-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7418402PMC
August 2020

The medial prefrontal cortex - hippocampus circuit that integrates information of object, place and time to construct episodic memory in rodents: Behavioral, anatomical and neurochemical properties.

Neurosci Biobehav Rev 2020 06 13;113:373-407. Epub 2020 Apr 13.

Center for Behavioral Neuroscience, Institute of Experimental Psychology, Heinrich-Heine University, Düsseldorf, Germany. Electronic address:

Rats and mice have been demonstrated to show episodic-like memory, a prototype of episodic memory, as defined by an integrated memory of the experience of an object or event, in a particular place and time. Such memory can be assessed via the use of spontaneous object exploration paradigms, variably designed to measure memory for object, place, temporal order and object-location inter-relationships. We review the methodological properties of these tests, the neurobiology about time and discuss the evidence for the involvement of the medial prefrontal cortex (mPFC), entorhinal cortex (EC) and hippocampus, with respect to their anatomy, neurotransmitter systems and functional circuits. The systematic analysis suggests that a specific circuit between the mPFC, lateral EC and hippocampus encodes the information for event, place and time of occurrence into the complex episodic-like memory, as a top-down regulation from the mPFC onto the hippocampus. This circuit can be distinguished from the neuronal component memory systems for processing the individual information of object, time and place.
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http://dx.doi.org/10.1016/j.neubiorev.2020.04.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7302494PMC
June 2020

Targeting inhibitory cerebellar circuitry to alleviate behavioral deficits in a mouse model for studying idiopathic autism.

Neuropsychopharmacology 2020 06 16;45(7):1159-1170. Epub 2020 Mar 16.

Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN, 55812, USA.

Autism spectrum disorder (ASD) encompasses wide-ranging neuropsychiatric symptoms with unclear etiology. Although the cerebellum is a key region implicated in ASD, it remains elusive how the cerebellar circuitry is altered and whether the cerebellum can serve as a therapeutic target to rectify the phenotype of idiopathic ASD with polygenic abnormalities. Using a syndromic ASD model, e.g., Black and Tan BRachyury TItpr3/J (BTBR) mice, we revealed that increased excitability of presynaptic interneurons (INs) and decreased intrinsic excitability of postsynaptic Purkinje neurons (PNs) resulted in low PN firing rates in the cerebellum. Knowing that downregulation of Kv1.2 potassium channel in the IN nerve terminals likely augmented their excitability and GABA release, we applied a positive Kv1.2 modulator to mitigate the presynaptic over-inhibition and social impairment of BTBR mice. Selective restoration of the PN activity by a new chemogenetic approach alleviated core ASD-like behaviors of the BTBR strain. These findings highlight complex mechanisms converging onto the cerebellar dysfunction in the phenotypic model and provide effective strategies for potential therapies of ASD.
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http://dx.doi.org/10.1038/s41386-020-0656-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7234983PMC
June 2020

Delayed expression of activity-dependent gating switch in synaptic AMPARs at a central synapse.

Mol Brain 2020 01 15;13(1). Epub 2020 Jan 15.

Program in Neurosciences & Mental Health, SickKids Research Institute, 555 University Ave, Toronto, Ontario, M5G 1X8, Canada.

Developing central synapses exhibit robust plasticity and undergo experience-dependent remodeling. Evidently, synapses in sensory systems such as auditory brainstem circuits mature rapidly to achieve high-fidelity neurotransmission for sound localization. This depends on a developmental switch in AMPAR composition from slow-gating GluA1-dominant to fast-gating GluA4-dominant, but the mechanisms underlying this switch remain unknown. We hypothesize that patterned stimuli mimicking spontaneous/sound evoked activity in the early postnatal stage drives this gating switch. We examined activity-dependent changes in evoked and miniature excitatory postsynaptic currents (eEPSCs and mEPSCs) at the calyx of Held synapse by breaking through the postsynaptic membrane at different time points following 2 min of theta burst stimulation (TBS) to afferents in mouse brainstem slices. We found the decay time course of eEPSCs accelerated, but this change was not apparent until > 30 min after TBS. Histogram analyses of the decay time constants of mEPSCs for naive and tetanized synapses revealed two populations centered around τ ≈ 0.4 and 0.8 ms, but the relative weight of the τ population over the τ population increased significantly only in tetanized synapses. Such changes are blocked by NMDAR or mGluR1/5 antagonists or inhibitors of CaMKII, PKC and protein synthesis, and more importantly precluded in GluA4 synapses, suggesting GluA4 is the substrate underlying the acceleration. Our results demonstrate a novel form of plasticity working through NMDAR and mGluR activation to trigger a gating switch of AMPARs with a temporally delayed onset of expression, ultimately enhancing the development of high-fidelity synaptic transmission.
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http://dx.doi.org/10.1186/s13041-019-0536-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6961283PMC
January 2020

Timing constraints of action potential evoked Ca current and transmitter release at a central nerve terminal.

Sci Rep 2019 03 14;9(1):4448. Epub 2019 Mar 14.

Department of Biomedical Sciences, University of Minnesota Medical School, 1035 University Drive, Duluth, MN, 55812, USA.

The waveform of presynaptic action potentials (APs) regulates the magnitude of Ca currents (I) and neurotransmitter release. However, how APs control the timing of synaptic transmission remains unclear. Using the calyx of Held synapse, we find that Na and K channels affect the timing by changing the AP waveform. Specifically, the onset of I depends on the repolarization but not depolarization rate of APs, being near the end of repolarization phase for narrow APs and advancing to the early repolarization phase for wide APs. Increasing AP amplitude has little effect on the activation but delays the peak time of I. Raising extracellular Ca concentration increases the amplitude of I yet does not alter their onset timing. Developmental shortening of APs ensures I as a tail current and faithful synaptic delay, which is particularly important at the physiological temperature (35 °C) as I evoked by broad pseudo-APs can occur in the depolarization phase. The early onset of I is more prominent at 35 °C than at 22 °C, likely resulting from a temperature-dependent shift in the activation threshold and accelerated gating kinetics of Ca channels. These results suggest that the timing of Ca influx depends on the AP waveform dictated by voltage-gated channels and temperature.
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http://dx.doi.org/10.1038/s41598-019-41120-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6418091PMC
March 2019

Anxiogenic-like behavior and deficient attention/working memory in rats expressing the human DISC1 gene.

Pharmacol Biochem Behav 2019 04 16;179:73-79. Epub 2019 Feb 16.

Center for Behavioral Neuroscience, Institute of Experimental Psychology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany. Electronic address:

In humans, mutations in the Disrupted-in-schizophrenia 1 (DISC1) gene have been related to psychiatric disorders, including symptoms of abnormal cognitive and emotional behaviors. In our previous studies, overexpression of the human DISC1 gene in rats resulted in schizophrenia-like phenotypes showing deficits in motor learning, impaired cognitive function and dysfunctions of the dopamine system. Here we asked, whether the DISC1 overexpression affects locomotor activity in the open field (OF), anxiety in the elevated plus-maze (EPM), depression-related behavior in the forced swim test (FST), and attention-like/short-term working-memory in the spontaneous alternation behavior (SAB) in the T-maze in transgenic DISC1 (tgDISC1) rats and littermate controls (WT). TgDISC1 rats showed enhanced anxiety behavior in the EPM and an impairment in attention-like/short-term working-memory in the SAB. However, tgDISC1 animals showed no locomotor impairments or depression-like behavior in the OF and FST. These results suggest that DISC1 overexpression leads to higher anxiety level and an attention-like/working-memory deficit. These findings may expand the causal role of DISC1 in its contribution to multiple symptom dimensions of psychiatric disorders.
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http://dx.doi.org/10.1016/j.pbb.2019.02.005DOI Listing
April 2019

Underpinning heterogeneity in synaptic transmission by presynaptic ensembles of distinct morphological modules.

Nat Commun 2019 02 18;10(1):826. Epub 2019 Feb 18.

Program in Neurosciences and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada.

Synaptic heterogeneity is widely observed but its underpinnings remain elusive. We addressed this issue using mature calyx of Held synapses whose numbers of bouton-like swellings on stalks of the nerve terminals inversely correlate with release probability (Pr). We examined presynaptic Ca currents and transients, topology of fluorescently tagged knock-in Ca channels, and Ca channel-synaptic vesicle (SV) coupling distance using Ca chelator and inhibitor of septin cytomatrix in morphologically diverse synapses. We found that larger clusters of Ca channels with tighter coupling distance to SVs elevate Pr in stalks, while smaller clusters with looser coupling distance lower Pr in swellings. Septin is a molecular determinant of the differences in coupling distance. Supported by numerical simulations, we propose that varying the ensemble of two morphological modules containing distinct Ca channel-SV topographies diversifies Pr in the terminal, thereby establishing a morpho-functional continuum that expands the coding capacity within a single synapse population.
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http://dx.doi.org/10.1038/s41467-019-08452-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6379440PMC
February 2019

Identification of a molecular locus for normalizing dysregulated GABA release from interneurons in the Fragile X brain.

Mol Psychiatry 2020 09 17;25(9):2017-2035. Epub 2018 Sep 17.

Program in Neurosciences & Mental Health, SickKids Research Institute, Toronto, ON, M5G 1X8, Canada.

Principal neurons encode information by varying their firing rate and patterns precisely fine-tuned through GABAergic interneurons. Dysregulation of inhibition can lead to neuropsychiatric disorders, yet little is known about the molecular basis underlying inhibitory control. Here, we find that excessive GABA release from basket cells (BCs) attenuates the firing frequency of Purkinje neurons (PNs) in the cerebellum of Fragile X Mental Retardation 1 (Fmr1) knockout (KO) mice, a model of Fragile X Syndrome (FXS) with abrogated expression of the Fragile X Mental Retardation Protein (FMRP). This over-inhibition originates from increased excitability and Ca transients in the presynaptic terminals, where Kv1.2 potassium channels are downregulated. By paired patch-clamp recordings, we further demonstrate that acutely introducing an N-terminal fragment of FMRP into BCs normalizes GABA release in the Fmr1-KO synapses. Conversely, direct injection of an inhibitory FMRP antibody into BCs, or membrane depolarization of BCs, enhances GABA release in the wild type synapses, leading to abnormal inhibitory transmission comparable to the Fmr1-KO neurons. We discover that the N-terminus of FMRP directly binds to a phosphorylated serine motif on the C-terminus of Kv1.2; and that loss of this interaction in BCs exaggerates GABA release, compromising the firing activity of PNs and thus the output from the cerebellar circuitry. An allosteric Kv1.2 agonist, docosahexaenoic acid, rectifies the dysregulated inhibition in vitro as well as acoustic startle reflex and social interaction in vivo of the Fmr1-KO mice. Our results unravel a novel molecular locus for targeted intervention of FXS and perhaps autism.
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http://dx.doi.org/10.1038/s41380-018-0240-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7473840PMC
September 2020

Corrigendum to "Behavioral assessments of BTBR T+Itpr3tf/J mice by tests of object attention and elevated open platform: implications for an animal model of psychiatric comorbidity in autism" [Behav. Brain Res. 347 (2018) 140-147].

Behav Brain Res 2019 01 6;356:516. Epub 2018 Sep 6.

Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN, USA. Electronic address:

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http://dx.doi.org/10.1016/j.bbr.2018.08.026DOI Listing
January 2019

Behavioral assessments of BTBR T+Itpr3tf/J mice by tests of object attention and elevated open platform: Implications for an animal model of psychiatric comorbidity in autism.

Behav Brain Res 2018 07 13;347:140-147. Epub 2018 Mar 13.

Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN, USA. Electronic address:

Autism spectrum disorders (ASD) are diagnosed based on the behavioral criteria of impaired social interaction, defective communication and repetitive behaviors. Psychiatric comorbidities, such as anxiety and intellectual disability, are commonly present in ASD. The BTBR T+ Itpr3tf/J (BTBR) mice display a range of autistic phenotypes, yet whether this mouse model is appropriate to study psychiatric comorbidity in ASD remains unclear. We addressed this issue by subjecting the BTBR animals to three-chambered apparatus, open field, object attention test and elevated open platform. Compared to C57BL/6J control mice, the BTBR mice displayed hyperactivity in most of the tests. In the three-chamber assessment, they exhibited deficits in sociability. In the open field, more grooming and thigmotaxis and less rearing behaviors were observed. They also showed impaired object-based attention. On the elevated open platform, the BTBR animals stayed more to the edges than in the center of the platform. To further examine the properties of this test, naïve C57BL/6J mice were randomly administrated with saline or an anxiogenic substance, caffeine. The caffeine group demonstrated a similar behavioral pattern as the BTBR mice. When the saline group was re-exposed to the same platform, the time they stayed in the center substantially increased, likely due to reduced anxiety by habituation. These results indicate that the BTBR were more anxious than control mice on the open platform. Taken together, the BTBR strain exhibit emotional and cognitive impairments in addition to autistic behaviors, suggesting that they can be a valid model for ASD with psychiatric comorbidity.
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http://dx.doi.org/10.1016/j.bbr.2018.03.014DOI Listing
July 2018

Ageing brains attend a symphony with asynchronous transmitter release.

J Physiol 2017 02;595(3):613-614

Program in Neurosciences and Mental Health, SickKids Research Institute and Department of Physiology, University of Toronto, Toronto, Ontario, M5G 1X8, Canada.

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http://dx.doi.org/10.1113/JP273421DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5285715PMC
February 2017

[Research Status of Application of Gold Nanoparticles in Medical Biotechnology].

Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2016 Apr;34(2):166-70

In recent years, gold nanoparticles (GNPs) have attracted more and more attention for their unique physical, chemical and biological properties, and are emerging as optical probes and biocompatibility materials for use. With the application of nanogold labeling technology in the medical field, detection techniques using GNPs as immune markers will become a major labeling technique, and will have wide applications in basic and clinical medicine. In this article, recent research progress on the applications of GNPs in the detection of pathogens, nucleic acids, and proteins and in the preparation of biosensors is reviewed.
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April 2016

Enhancing the fidelity of neurotransmission by activity-dependent facilitation of presynaptic potassium currents.

Nat Commun 2014 Jul 31;5:4564. Epub 2014 Jul 31.

1] Program in Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada M5G 1X8 [2] Department of Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8.

Neurons convey information in bursts of spikes across chemical synapses where the fidelity of information transfer critically depends on synaptic input-output relationship. With a limited number of synaptic vesicles (SVs) in the readily releasable pool (RRP), how nerve terminals sustain transmitter release during intense activity remains poorly understood. Here we report that presynaptic K(+) currents evoked by spikes facilitate in a Ca(2+)-independent but frequency- and voltage-dependent manner. Experimental evidence and computer simulations demonstrate that this facilitation originates from dynamic transition of intermediate gating states of voltage-gated K(+) channels (Kvs), and specifically attenuates spike amplitude and inter-spike potential during high-frequency firing. Single or paired recordings from a mammalian central synapse further reveal that facilitation of Kvs constrains presynaptic Ca(2+) influx, thereby efficiently allocating SVs in the RRP to drive postsynaptic spiking at high rates. We conclude that presynaptic Kv facilitation imparts neurons with a powerful control of transmitter release to dynamically support high-fidelity neurotransmission.
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http://dx.doi.org/10.1038/ncomms5564DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4503407PMC
July 2014

[Preliminary survey on the host of Angiostrongylus cantonensis in three plateau lakes of Yunnan Province].

Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2014 Apr;32(2):139-42, 147

Objective: To investigated the intermediate hosts of Angiostrongylus cantonensis in three plateau lakes of Yunnan Province, and analyze the effect of temperature on A. cantonensis during 1991-2010.

Methods: An epidemiological investigation of angiostrongyliasis cantonensis in Erhai Lake, Fuxian Lake and Xingyun Lake was conducted from April to September in 2012. Snails were examined for the third stage larvae by enzyme digestion or lung examination. Rodents were captured in the fields, and their hearts and lungs were dissected for adult worms. The potential distribution of A. cantonensis and its main intermediate host Pomacea canaliculata were predicted based on degree-day models using GIS technique.

Results: A total of 4 950 snails were collected, belonging to 4 species, P. canaliculata, Cipangopaludina chinensis, Bellamya aeruginosa, and B. quadrata. 174 rodents were captured, belonging to 5 species. No positive samples were found. The potential distribution map showed that the distribution of A. cantonensis and P. canaliculata in Yunnan would expand with the rise of temperature, and with the passage of time they could complete one generation in the region which couldn't finish one generation in one year along with time passing.

Conclusion: A. cantonensis are not found in the hosts. The natural environment and ecological system of the three lakes match the condition of A. cantonensis transmission.
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April 2014

[Application of PCR and PCR-derived technologies in the detection of Angiostrongylus cantonensis].

Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2012 Aug;30(4):321-4

Department of Parasitology, College of Basic Medical Science, Dali University, Dali 671000, China.

Angiostrongyliasis is a zoonotic disease and has become one of the potentially threatening food-borne parasitic infections in China. This article reviews the advances in the application of PCR and PCR-derived techniques in detection of Angiostrongylus cantonensis.
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August 2012

[Killing effect of garlic extract on Schistosoma japonicum cercariae and Oncomelania snails].

Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2012 Jun;30(3):245-6

Faculty of Clinical Medicine, Dali University, Dali 671000, China.

The killing effect of different concentrations of garlic extract solution on Schistosoma japonicum cercariae and Oncomelania snails was observed under dissecting microscope. Mice were infected by cercariae through the abdominal skin daubed by garlic solution or by deionized water as control. The results showed that the cercariae were killed in (77.33 +/- 25.01) s in average, it needed (73.00 +/- 1.73)- (299.67 +/- 18.96) s under the garlic solution concentrations of 50.00%-0.79% respectively, while the cercariae kept alive in 600 s in the control. The snails were killed in 1 d by 100% garlic solution but no death in the control in 2 d. No mouse daubed with different concentrations of garlic solution was found infected by schistosomes while 100% of the control mice got infected. It is concluded that the garlic shows satisfactory effect in killing cercariae and Oncomelania snails, and may prevent schistosome infection by daubing the skin.
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June 2012

[Application of immune colloidal gold technique on the diagnosis of parasitoses].

Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2011 Aug;29(4):305-9

Department of Parasitology, Faculty of Basic Medical Sciences, Dali University, Dali 671000, China.

Immune colloidal gold (ICG) technique is a simple, rapid, accurate diagnosis method. At present, ICG technique has been widely applied in the accessory diagnosis of parasitoses, and this article reviews the latest progress of ICG technique applied in parasitology.
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August 2011

[Application of molecular biological techniques in Taenia identification].

Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2011 Oct;29(5):385-8

The traditional identification of Taenia spp. based on morphological features of adult and cysticercus has difficulties in identifying the morphologically similar species. The recent development of molecular techniques provides more scientific ways for distinguishing Taenia species. This paper summarizes the application of molecular biological techniques in the identification of Taenia, such as analysis of DNA sequence, PCR-RFLP and LAMP.
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October 2011

GluA4 is indispensable for driving fast neurotransmission across a high-fidelity central synapse.

J Physiol 2011 Sep 20;589(17):4209-27. Epub 2011 Jun 20.

Program in Neurosciences & Mental Health, The Hospital For Sick Children and Department of Physiology, University of Toronto, 555 University Avenue, Toronto, Ontario, Canada.

Fast excitatory synaptic transmission in central synapses is mediated primarily by AMPA receptors (AMPARs), which are heteromeric assemblies of four subunits, GluA1-4. Among these subunits, rapidly gating GluA3/4 appears to be the most abundantly expressed to enable neurotransmission with submillisecond precision at fast rates in subsets of central synapses. However, neither definitive identification of the molecular substrate for native AMPARs in these neurons, nor their hypothesized functional roles in vivo has been unequivocally demonstrated, largely due to lack of specific antagonists. Using GluA3 or GluA4 knockout (KO) mice, we investigated these issues at the calyx of Held synapse, which is known as a high-fidelity synapse involved in sound localization. Patch-clamp recordings from postsynaptic neurons showed that deletion of GluA4 significantly slowed the time course of both evoked and miniature AMPAR-mediated excitatory postsynaptic currents (AMPAR-EPSCs), reduced their amplitude, and exacerbated AMPAR desensitization and short-term depression (STD). Surprisingly, presynaptic release probability was also elevated, contributing to severe STD at GluA4-KO synapses. In contrast, only marginal changes in AMPAR-EPSCs were found in GluA3-KO mice. Furthermore, independent of changes in intrinsic excitability of postsynaptic neurons, deletion of GluA4 markedly reduced synaptic drive and increased action potential failures during high-frequency activity, leading to profound deficits in specific components of the auditory brainstem responses associated with synchronized spiking in the calyx of Held synapse and other related neurons in vivo. These observations identify GluA4 as the main determinant for fast synaptic response, indispensable for driving high-fidelity neurotransmission and conveying precise temporal information.
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http://dx.doi.org/10.1113/jphysiol.2011.208066DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3180579PMC
September 2011

Action potential bursts enhance transmitter release at a giant central synapse.

J Physiol 2011 May 28;589(Pt 9):2213-27. Epub 2011 Feb 28.

Institute of Molecular Medicine, Peking University, Beijing 100871, China.

Patterns of action potentials (APs), often in the form of bursts, are critical for coding and processing information in the brain. However, how AP bursts modulate secretion at synapses remains elusive. Here, using the calyx of Held synapse as a model we compared synaptic release evoked by AP patterns with a different number of bursts while the total number of APs and frequency were fixed. The ratio of total release produced by multiple bursts to that by a single burst was defined as 'burst-effect'.We found that four bursts of 25 stimuli at 100 Hz increased the totalcharge of EPSCs to 1.47 ± 0.04 times that by a single burst of 100 stimuli at the same frequency.Blocking AMPA receptor desensitization and saturation did not alter the burst-effect, indicating that it was mainly determined by presynaptic mechanisms. Simultaneous dual recordings of presynaptic membrane capacitance (Cm) and EPSCs revealed a similar burst-effect, being 1.58±0.13by Cm and 1.49±0.05 by EPSCs. Reducing presynapticCa2+ influx by lowering extracellular Ca2+concentration or buffering residual intracellular Ca2+ with EGTA inhibited the burst-effect. We further developed a computational model largely recapitulating the burst-effect and demonstrated that this effect is highly sensitive to dynamic change in availability of the releasable pool of synaptic vesicles during various patterns of activities. Taken together, we conclude that AP bursts modulate synaptic output mainly through intricate interaction between depletion and replenishment of the large releasable pool. This burst-effect differs from the somatic burst-effect previously described from adrenal chromaffin cells, which substantially depends on activity-induced accumulation of Ca2+ to facilitate release of a limited number of vesicles in the releasable pool. Hence, AP bursts may play an important role in dynamically regulating synaptic strength and fidelity during intense neuronal activity at central synapses.
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http://dx.doi.org/10.1113/jphysiol.2010.200154DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3098699PMC
May 2011

Septins regulate developmental switching from microdomain to nanodomain coupling of Ca(2+) influx to neurotransmitter release at a central synapse.

Neuron 2010 Jul;67(1):100-15

Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada.

Neurotransmitter release depends critically on close spatial coupling of Ca(2+) entry to synaptic vesicles at the nerve terminal; however, the molecular substrates determining their physical proximity are unknown. Using the calyx of Held synapse, where "microdomain" coupling predominates at immature stages and developmentally switches to "nanodomain" coupling, we demonstrate that deletion of the filamentous protein Septin 5 imparts immature synapses with striking morphological and functional features reminiscent of mature synapses. This includes synaptic vesicles tightly localized to active zones, resistance to the slow Ca(2+) buffer EGTA and a reduced number of Ca(2+) channels required to trigger single fusion events. Disrupting Septin 5 organization acutely transforms microdomain to nanodomain coupling and potentiates quantal output in immature wild-type terminals. These observations suggest that Septin 5 is a core molecular substrate that differentiates distinct release modalities at the central synapse.
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http://dx.doi.org/10.1016/j.neuron.2010.06.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5145303PMC
July 2010

Action potential evoked transmitter release in central synapses: insights from the developing calyx of Held.

Mol Brain 2009 Nov 25;2:36. Epub 2009 Nov 25.

Program for Neurosciences and Mental Health, The Hospital for Sick Children and Department of Physiology, University of Toronto, 555 University Avenue, Toronto, Ontario, M5G 1X8, Canada.

Chemical synapses are the fundamental units that mediate communication between neurons in the mammalian brain. In contrast to the enormous progress made in mapping out postsynaptic contributions of receptors, scaffolding structures and receptor trafficking to synaptic transmission and plasticity, the small size of nerve terminals has largely precluded direct analyses of presynaptic modulation of excitability and transmitter release in central synapses. Recent studies performed in accessible synapses such as the calyx of Held, a giant axosomatic synapse in the sound localization circuit of the auditory brainstem, have provided tremendous insights into how central synapses regulate the dynamic gain range of synaptic transmission. This review will highlight experimental evidence that resolves several long-standing issues with respect to intricate interplays between the waveform of action potentials, Ca2+ currents and transmitter release and further conceptualize their relationships in a physiological context with theoretical models of the spatial organization of voltage-gated Ca2+ channels and synaptic vesicles at release sites.
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http://dx.doi.org/10.1186/1756-6606-2-36DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2794261PMC
November 2009

[One case with 14 tapeworms (Taenia saginata asiatica) expelled].

Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2009 Jun;27(3):1 p following 290

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June 2009

[Application of molecular marker techniques in taxonomic identification of parasites].

Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2009 Jun;27(3):261-6

Department of Parasitology, School of Basic Medicine, Dali University, Dali 671000, China.

Different subspecies or strains of the same species produce varied clinical manifestations. The clarification of parasite taxonomy is useful for the researches of their biology, epidemiology and control. DNA molecular markers have the advantages of high polymorphism, non-pleiotropy, and clear identifying alleles, etc. This paper summarizes the first generation (restriction fragment length polymorphism, random amplified polymorphic DNA), second generation (simple sequence repeat-anchored PCR, inter-simple sequence repeat) and third generation (single nucleotide polymorphism) molecular marker techniques, and their application in taxonomic identification of parasites.
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June 2009

Coincident activation of metabotropic glutamate receptors and NMDA receptors (NMDARs) downregulates perisynaptic/extrasynaptic NMDARs and enhances high-fidelity neurotransmission at the developing calyx of Held synapse.

J Neurosci 2007 Sep;27(37):9989-99

The Program for Neurosciences and Mental Health and Division of Neurology, The Hospital for Sick Children, and Department of Physiology, University of Toronto, Toronto, Ontario, Canada M5G 1X8.

NMDA receptors (NMDARs) are usually downregulated in developing central synapses, but underlying mechanisms and functional consequences are not well established. Using developing calyx of Held synapses in the mouse auditory brainstem, we show here that pairing presynaptic stimulation with postsynaptic depolarization results in a persistent downregulation in the summated amplitude of NMDAR-mediated EPSCs (NMDAR-EPSCs) during a train of stimuli (100/200 Hz, 100 ms) at both 22 degrees C and 35 degrees C. In contrast, the amplitude of single NMDAR-EPSCs or AMPA receptor-mediated EPSCs in the same synapses is not significantly altered, implying a preferential downregulation of perisynaptic/extrasynaptic NMDARs. Induction of this downregulation is blocked by antagonists for NMDARs or group I metabotropic glutamate receptors (mGluRs), suggesting that coincident activation of these two receptors is required. When the postsynaptic neuron is loaded with the fast Ca2+ buffer BAPTA or depolarized to +60 mV to reduce the driving force for Ca2+ influx, downregulation of the summated NMDAR-EPSCs is abolished, indicating Ca2+ plays a critical role in the induction. The expression of this downregulation depends on ongoing synaptic activity, and is attenuated by a dynamin peptide (D15) that blocks clathrin-dependent internalization. We further demonstrated that the same induction paradigm specifically reduces NMDAR-dependent plateau potential and aberrant spike firings during repetitive activity. Together, our results suggest that coincident activation of mGluRs and NMDARs during intense synaptic activity may lead to selective endocytosis of NMDARs in the perisynaptic/extrasynaptic domain, and implicate that mGluRs are potentially important for gating development of high-fidelity neurotransmission at this synapse.
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http://dx.doi.org/10.1523/JNEUROSCI.2506-07.2007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6672635PMC
September 2007

Amplitude and kinetics of action potential-evoked Ca2+ current and its efficacy in triggering transmitter release at the developing calyx of Held synapse.

J Neurosci 2006 May;26(21):5698-708

Division of Neurology, The Hospital for Sick Children, Department of Physiology, University of Toronto, Toronto, Ontario, M5G 1X8, Canada.

Action potentials (APs) play a crucial role in evoking Ca2+ currents (ICa) through voltage-gated calcium channels (VGCCs) and transmitter release. During development and neuromodulation, both depolarization and repolarization phases of APs change, but how such changes affect the characteristics of ICa and its efficacy at central synapses is not clear. By paired voltage-clamp recordings of ICa and excitatory postsynaptic currents (IEPSC) with pseudo-APs and real APs, we examined these issues in the developing calyx of Held synapse of postnatal mice. We found that speeding the AP depolarization rate primarily reduces the number of activated VGCCs, whereas shortening the AP repolarization phase decreases the number of activated VGCCs and accelerates their kinetics. The ICa-IESPC relationships are well predicted by the integral but not the amplitude of ICa, and exhibit development- and temperature-dependent shifts toward left, indicating an enhancement in downstream Ca2+ coupling efficacy. Cross-correlation analyses of ICa and IEPSC evoked by real APs and pseudo-APs demonstrated that AP shortening in the half-width from 0.4 ms at postnatal day 8 (P8)-P12 to 0.27 ms at P16-P18 decreases ICa integral by 36%, but increases IEPSC by 72% as a result of developmental upregulation in coupling efficacy. These counteracting actions maintain the release fraction evoked by an AP at approximately 10% of the maximal quantal output. We suggest that AP narrowing is a critical adaptation for the calyx of Held synapse to control the quantal output per AP and is likely important for the efficient use of the readily releasable pool of synaptic vesicles during high-frequency neurotransmission.
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http://dx.doi.org/10.1523/JNEUROSCI.4889-05.2006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6675268PMC
May 2006
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