114 results match your criteria activate short-latency


Cortico-cortical connectivity: the road from basic neurophysiological interactions to therapeutic applications.

Authors:
Giacomo Koch

Exp Brain Res 2020 Aug 23;238(7-8):1677-1684. Epub 2020 Jul 23.

Non Invasive Brain Stimulation Unit, Laboratorio Di Neurologia Clinica E Comportamentale, IRCCS Fondazione S. Lucia, Via Ardeatina, 306, 00179, Rome, Italy.

Transcranial magnetic stimulation (TMS) based methods are emerging as a unique approach to evaluate in real-time brain electrical activity in healthy and pathological conditions. By applying TMS pulses in two different bran areas within a short temporal frame of few milliseconds, it is possible to investigate their physiological interactions. These paradigms, collectively termed dual-site TMS, have been inspired by Professor John Rothwell's work, based on the idea that applying a conditioning stimulus over a cortical area may activate putative pathways projecting onto a second target area, thus providing a unique opportunity to test the causal effects between interconnected brain areas. Read More

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Priming Effects of Water Immersion on Paired Associative Stimulation-Induced Neural Plasticity in the Primary Motor Cortex.

Int J Environ Res Public Health 2019 12 27;17(1). Epub 2019 Dec 27.

Department of Rehabilitation Medicine, Kagoshima University, Sakuragaoka 8-35-1, Kagoshima City, Kagoshima 890-8520, Japan.

We aimed to verify whether indirect-wave (I-wave) recruitment and cortical inhibition can regulate or predict the plastic response to paired associative stimulation with an inter-stimulus interval of 25 ms (PAS25), and also whether water immersion (WI) can facilitate the subsequent PAS25-induced plasticity. To address the first question, we applied transcranial magnetic stimulation (TMS) to the M1 hand area, while alternating the direction of the induced current between posterior-to-anterior and anterior-to-posterior to activate two independent synaptic inputs to the corticospinal neurons. Moreover, we used a paired stimulation paradigm to evaluate the short-latency afferent inhibition (SAI) and short-interval intracortical inhibition (SICI). Read More

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December 2019

Multimodal stimuli modulate rapid visual responses during reaching.

J Neurophysiol 2019 11 11;122(5):1894-1908. Epub 2019 Sep 11.

Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom.

The reticulospinal tract plays an important role in primate upper limb function, but methods for assessing its activity are limited. One promising approach is to measure rapid visual responses (RVRs) in arm muscle activity during a visually cued reaching task; these may arise from a tecto-reticulospinal pathway. We investigated whether changes in reticulospinal excitability can be assessed noninvasively using RVRs, by pairing the visual stimuli of the reaching task with electrical stimulation of the median nerve, galvanic vestibular stimulation, or loud sounds, all of which are known to activate the reticular formation. Read More

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November 2019

Muscle-selective disinhibition of corticomotor representations using a motor imagery-based brain-computer interface.

Neuroimage 2018 12 30;183:597-605. Epub 2018 Aug 30.

Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Kanagawa, Japan; Keio Research Institute for Pure and Applied Sciences (KiPAS), Keio University, Kanagawa, Japan. Electronic address:

Bridging between brain activity and machine control, brain-computer interface (BCI) can be employed to activate distributed neural circuits implicated in a specific aspect of motor control. Using a motor imagery-based BCI paradigm, we previously found a disinhibition within the primary motor cortex contralateral to the imagined movement, as evidenced by event-related desynchronization (ERD) of oscillatory cortical activity. Yet it is unclear whether this BCI approach does selectively facilitate corticomotor representations targeted by the imagery. Read More

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December 2018

Otolithic Receptor Mechanisms for Vestibular-Evoked Myogenic Potentials: A Review.

Front Neurol 2018 25;9:366. Epub 2018 May 25.

MSA ENT Academy Center, Cassino, Italy.

Air-conducted sound and bone-conduced vibration activate otolithic receptors and afferent neurons in both the utricular and saccular maculae, and trigger small electromyographic (EMG) responses [called vestibular-evoked myogenic potentials (VEMPs)] in various muscle groups throughout the body. The use of these VEMPs for clinical assessment of human otolithic function is built on the following logical steps: (1) that high-frequency sound and vibration at clinically effective stimulus levels activate otolithic receptors and afferents, rather than semicircular canal afferents, (2) that there is differential anatomical projection of otolith afferents to eye muscles and neck muscles, and (3) that isolated stimulation of the utricular macula induces short latency responses in eye muscles, and that isolated stimulation of the saccular macula induces short latency responses in neck motoneurons. Evidence supports these logical steps, and so VEMPs are increasingly being used for clinical assessment of otolith function, even differential evaluation of utricular and saccular function. Read More

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Sensory, Motor and Intrinsic Mechanisms of Thalamic Activity related to Organic and Psychogenic Dystonia.

J Alzheimers Dis Parkinsonism 2017 Jun 15;7(3). Epub 2017 May 15.

Departments of Neurosurgery and Neurology Johns Hopkins Hospital, Baltimore, MD, USA.

The thalamus is a critical module in the circuit which has been associated with movement disorders including dystonia. This circuit extends from cortex to striatum to pallidum to the thalamic nucleus Ventral Lateral anterior (VLa) to cortex and can be studied by activity recorded during thalamic stereotactic surgery for the treatment of dystonia. Neuronal recordings in the VLa nucleus show low frequency modulation of firing that is correlated with and leads the low frequency modulation of EMG activity; this EMG activity is characteristic of dystonia. Read More

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Left hemispheric breakdown of LTP-like cortico-cortical plasticity in schizophrenic patients.

Clin Neurophysiol 2017 10 14;128(10):2037-2042. Epub 2017 Jul 14.

Non-invasive Brain Stimulation Unit, Laboratorio di Neurologia Clinica e Comportamentale, Fondazione Santa Lucia IRCCS, Via Ardeatina 306, 00179 Rome, Italy; Stroke Unit, Policlinico Tor Vergata, Rome, Italy.

Objective: Altered cortical connectivity and plasticity seems to be asymmetrical between the hemispheres in patients with schizophrenia (SCZ). We evaluated long-term potentiation (LTP) in parietal-frontal circuits of both hemispheres using a cortico-cortical Paired Associative Stimulation (cc-PAS) protocol testing the rules of Hebbian-like spike timing dependent plasticity (SPTD).

Methods: 12 SCZ and 12 healthy subjects (HS) underwent a cc-PAS protocol to activate, by means of paired pulses of transcranial magnetic stimulation (TMS), the short-latency connection between posterior parietal cortex (PPC) and primary motor cortex (M1) of both hemispheres. Read More

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October 2017

Short-latency muscle response patterns to multi-directional, unpredictable perturbations to balance applied to the arm are context dependent.

Neuroscience 2017 06 8;352:170-179. Epub 2017 Apr 8.

Department of Kinesiology and Physical Education, McGill University, 475 Pine Avenue West, Montreal, Quebec H2S 1S4, Canada. Electronic address:

A number of studies have shown that sensory inputs from the hand can have a profound effect in stabilizing upright posture. This suggests that the central nervous system can extract information about body motion and external forces acting on the body from cutaneous sensory signals. We have recently shown that the central nervous system determines the direction of an unpredictable force applied to the hand so rapidly that it is able to activate ankle muscles in advance of the perturbing effect that this force has at the ankles. Read More

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Orbitofrontal Cortex Neurons Respond to Sound and Activate Primary Auditory Cortex Neurons.

Cereb Cortex 2018 03;28(3):868-879

Institute for Systems Research, University of Maryland, College Park, MD 20742, USA.

Sensory environments change over a wide dynamic range and sensory processing can change rapidly to facilitate stable perception. While rapid changes may occur throughout the sensory processing pathway, cortical changes are believed to profoundly influence perception. Prior stimulation studies showed that orbitofrontal cortex (OFC) can modify receptive fields and sensory coding in A1, but the engagement of OFC during listening and the pathways mediating OFC influences on A1 are unknown. Read More

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Pulse Duration as Well as Current Direction Determines the Specificity of Transcranial Magnetic Stimulation of Motor Cortex during Contraction.

Brain Stimul 2017 Jan - Feb;10(1):106-115. Epub 2016 Oct 5.

Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK.

Background: Previous research suggested that anterior-posterior (AP) directed currents induced by TMS in motor cortex (M1) activate interneuron circuits different from those activated by posterior-anterior currents (PA). The present experiments provide evidence that pulse duration also determines the activation of specific interneuron circuits.

Objective: To use single motor unit (SMU) recordings to confirm the difference in onset latencies of motor-evoked potentials (MEPs) evoked by different current directions and pulse durations: AP, AP, PA and PA. Read More

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September 2017

The inion response revisited: evidence for a possible cerebellar contribution to vestibular-evoked potentials produced by air-conducted sound stimulation.

J Neurophysiol 2017 03 14;117(3):1000-1013. Epub 2016 Dec 14.

Prince of Wales Clinical School and Neuroscience Research Australia, University of New South Wales, Randwick, Sydney, Australia

This study investigated the effect of eye gaze and head position on vestibular-evoked potentials (VsEPs). Head position would be expected to affect myogenic sources, and eye position is known to affect ocular myogenic responses (ocular vestibular-evoked myogenic potentials), whereas a neurogenic source should behave otherwise. Eleven healthy subjects were recruited, and VsEPs, using 72-channel EEG, were recorded at a fixed intensity above the vestibular threshold. Read More

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Cortical Control of Striatal Dopamine Transmission via Striatal Cholinergic Interneurons.

Cereb Cortex 2016 Oct;26(11):4160-4169

Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.

Corticostriatal regulation of striatal dopamine (DA) transmission has long been postulated, but ionotropic glutamate receptors have not been localized directly to DA axons. Striatal cholinergic interneurons (ChIs) are emerging as major players in striatal function, and can govern DA transmission by activating nicotinic receptors (nAChRs) on DA axons. Cortical inputs to ChIs have historically been perceived as sparse, but recent evidence indicates that they strongly activate ChIs. Read More

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October 2016

Effects of Optogenetic Activation of Corticothalamic Terminals in the Motor Thalamus of Awake Monkeys.

J Neurosci 2016 Mar;36(12):3519-30

Yerkes National Primate Research Center and School of Medicine, Department of Neurology, Emory University, Atlanta, Georgia 30329.

Unlabelled: The role of the corticothalamic projection in the ventral motor thalamus remains poorly understood. Therefore, we studied the electrophysiological responses of neurons in the basal ganglia and cerebellar receiving-territories of the motor thalamus (BGMT and CbMT, respectively) using optogenetic activation of corticothalamic projections in awake rhesus macaques. After injections of viral vectors carrying the excitatory opsins ChR2 or C1V1 into the primary motor and premotor cortices of two monkeys, we used optrodes to light activate opsin-expressing neurons in cortex or their terminals in the thalamus while simultaneously recording the extracellular activity of neurons in the vicinity of the stimulation sites. Read More

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A convergent and essential interneuron pathway for Mauthner-cell-mediated escapes.

Curr Biol 2015 Jun 7;25(11):1526-34. Epub 2015 May 7.

Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; FAS Center for Systems Biology, Harvard University, MA 02138, USA. Electronic address:

The Mauthner cell (M-cell) is a command-like neuron in teleost fish whose firing in response to aversive stimuli is correlated with short-latency escapes [1-3]. M-cells have been proposed as evolutionary ancestors of startle response neurons of the mammalian reticular formation [4], and studies of this circuit have uncovered important principles in neurobiology that generalize to more complex vertebrate models [3]. The main excitatory input was thought to originate from multisensory afferents synapsing directly onto the M-cell dendrites [3]. Read More

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Oestradiol and prostaglandin F2α regulate sexual displays in females of a sex-role reversed fish.

Proc Biol Sci 2014 Mar 22;281(1778):20133070. Epub 2014 Jan 22.

Eco-Ethology Research Unit, ISPA-Instituto Universitário, , Rua Jardim do Tabaco 34, Lisboa 1149-041, Portugal, Centro de Ciências do Mar, Universidade do Algarve, , Campus de Gambelas, Faro 8005-139, Portugal, Department of Science and Environment, University of St Joseph, , Rua de Londres 16, Macau, People's Republic of China (SAR), Champalimaud Neuroscience Programme, Instituto Gulbenkian de Ciência, , Oeiras, Portugal.

The mechanisms regulating sexual behaviours in female vertebrates are still poorly understood, mainly because in most species sexual displays in females are more subtle and less frequent than displays in males. In a sex-role reversed population of a teleost fish, the peacock blenny Salaria pavo, an external fertilizer, females are the courting sex and their sexual displays are conspicuous and unambiguous. We took advantage of this to investigate the role of ovarian-synthesized hormones in the induction of sexual displays in females. Read More

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Microcircuit mechanisms involved in paired associative stimulation-induced depression of corticospinal excitability.

J Physiol 2013 Oct 15;591(19):4903-20. Epub 2013 Jul 15.

J. Classen: University of Leipzig, Department of Neurology, Liebigstr. 20, Leipzig 04103, Germany.

Synaptic weight changes induced by temporal correlations between the spikes of pre- and postsynaptic neurons are referred to as spike-timing-dependent plasticity (STDP). Transcranial magnetic stimulation (TMS) induces long-lasting effects on corticospinal excitability, if it is repetitively paired with stimulation of afferents from a corresponding contralateral hand region at short intervals (paired associative stimulation, PAS). PAS-induced plasticity has been linked with synaptic STDP. Read More

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October 2013

Hebbian and anti-Hebbian spike-timing-dependent plasticity of human cortico-cortical connections.

J Neurosci 2013 Jun;33(23):9725-33

Non-Invasive Brain Stimulation Unit, Santa Lucia Foundation, Institute for Inpatient Treatment and Scientific Studies, I-00179 Rome, Italy.

Learning of new skills may occur through Hebbian associative changes in the synaptic strength of cortical connections [spike-timing-dependent plasticity (STDP)], but how the precise temporal relationship of the presynaptic and postsynaptic inputs determines the STDP effects in humans is poorly understood. We used a novel paired associative stimulation protocol to repeatedly activate the short-latency connection between the posterior parietal cortex and the primary motor cortex (M1) of the left-dominant hemisphere. In different experiments, we systematically varied the temporal relationships between the stimuli and the preferential activation of different M1 neuronal populations by applying transcranial magnetic stimulation over M1 with different coil orientations and in different states of cortical excitability (rest vs muscular contraction). Read More

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A postural reflex evoked by brief axial accelerations.

Exp Brain Res 2013 Jul 21;228(1):73-85. Epub 2013 May 21.

Prince of Wales Clinical School, University of New South Wales, Randwick, Sydney, NSW, 2031, Australia.

Impulsive stimuli were used to evoke postural reflexes in healthy subjects (n = 10) and avestibular patients (n = 2). Electromyographic (EMG) activity was recorded with subjects standing erect, feet together with eyes closed and leaning forward to activate their leg muscles. EMG was recorded bilaterally from over the soleus muscles, rectified and averaged. Read More

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Event time representation in cerebellar mossy fibres arising from the lateral reticular nucleus.

J Physiol 2013 Feb 26;591(4):1045-62. Epub 2012 Nov 26.

Department of Physiology, Development and Neuroscience, Downing Street, University of Cambridge, Cambridge, UK.

Time representation is an important element of cerebellar neural processing, but the mechanisms involved are poorly understood. We demonstrate that the major mossy fibre input system originating from the lateral reticular nucleus (LRN) can represent sensory event timing over hundreds of milliseconds. In vivo, cerebellar-projecting LRN neurons discharge extremely regularly with a clock-like rhythm. Read More

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February 2013

The amygdala and the pedunculopontine tegmental nucleus: interactions controlling active (rapid eye movement) sleep.

Exp Neurol 2012 Nov 17;238(1):44-51. Epub 2012 Aug 17.

Websciences International, Los Angeles, CA 90024, USA.

There is a consensus that active sleep (AS; i.e., REM sleep) is produced by cholinergic projections from the pedunculopontine tegmental nuclei (PPT) that activate AS-on neurons in the nucleus pontis oralis (NPO) that are components of the AS-Generator. Read More

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November 2012

Vestibular-dependent spinal reflexes evoked by brief lateral accelerations of the heads of standing subjects.

J Appl Physiol (1985) 2012 Jun 5;112(11):1906-14. Epub 2012 Apr 5.

Prince of Wales Clinical School, University of New South Wales, Randwick, Sydney, New South Wales, Australia.

An impulsive acceleration stimulus, previously shown to activate vestibular afferents, was applied to the mastoid. Evoked EMG responses from the soleus muscles in healthy subjects (n = 10) and patients with bilateral vestibular dysfunction (n = 3) were recorded and compared with the effects of galvanic stimulation (GVS). Subjects were stimulated while having their eyes closed, head rotated, and while tonically activating their soleus muscles. Read More

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Bone conducted vibration activates the vestibulo-ocular reflex in the guinea pig.

Brain Res Bull 2011 Aug 1;86(1-2):74-81. Epub 2011 Jul 1.

Vestibular Research Laboratory School of Psychology, University of Sydney, NSW, Australia.

The aim of the study was: (a) to test whether short duration (6 ms) 500 Hz bone-conducted vibration (BCV) of the skull in alert head free guinea pigs would elicit eye movements; (b) to test whether these eye movements were vestibular in origin; and (c) to determine whether they corresponded to human eye movements to such stimuli. In this way we sought to establish the guinea pig as an acceptable model for testing the mechanism of the effect BCV on the vestibulo-ocular reflex. Consistent short-latency stimulus-locked responses to BCV were observed. Read More

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The human splice variant Δ16HER2 induces rapid tumor onset in a reporter transgenic mouse.

PLoS One 2011 Apr 29;6(4):e18727. Epub 2011 Apr 29.

Department of Bioscience and Biotechnology, University of Camerino, Camerino, Italy.

Several transgenic mice models solidly support the hypothesis that HER2 (ERBB2) overexpression or mutation promotes tumorigenesis. Recently, a HER2 splice variant lacking exon-16 (Δ16HER2) has been detected in human breast carcinomas. This alternative protein, a normal byproduct of HER2, has an increased transforming potency compared to wild-type (wt) HER2 receptors. Read More

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Long-lasting contralateral motor cortex excitability is increased by unilateral hand movement that triggers electrical stimulation of opposite homologous muscles.

Neurorehabil Neural Repair 2011 Jul-Aug;25(6):521-30. Epub 2011 Mar 24.

Motor Control Laboratory, School of Psychology, University of Tasmania, Hobart, Tasmania, Australia.

Background/objective: Long-term changes in the motor cortex can be induced by practicing motor tasks with simultaneous application of peripheral nerve stimulation. This combination may augment motor rehabilitation after stroke but has been used primarily during contraction of the affected hand. The authors tested the effect of a right hand movement that electrically stimulated left hand contraction on right motor cortex excitability. Read More

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BA3b and BA1 activate in a serial fashion after median nerve stimulation: direct evidence from combining source analysis of evoked fields and cytoarchitectonic probabilistic maps.

Neuroimage 2011 Jan 4;54(1):60-73. Epub 2010 Aug 4.

Laboratory for Human Brain Dynamics, Brain Science Institute (BSI), RIKEN, Saitama, Japan.

This study combines source analysis imaging data for early somatosensory processing and the probabilistic cytoarchitectonic maps (PCMs). Human somatosensory evoked fields (SEFs) were recorded by stimulating left and right median nerves. Filtering the recorded responses in different frequency ranges identified the most responsive frequency band. Read More

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January 2011

Comparison of activity characteristics of the cuneate nucleus and thoracic spinal neurons receiving noxious cardiac and/or somatic inputs in rats.

Brain Res 2010 Jul 2;1346:102-11. Epub 2010 Jun 2.

Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73190, USA.

Previous studies have shown that the gracile nucleus in postsynaptic dorsal column pathway plays an important role in conveying nociceptive information from pelvic visceral organs. The purpose of this study was to compare effects of a noxious cardiac stimulus on neuronal activity in the cuneate nucleus and upper thoracic spinal cord in rats. Extracellular potentials of single neurons in the cuneate nucleus and upper thoracic (T3) spinal cord were recorded in pentobarbital anesthetized, ventilated and paralyzed male rats. Read More

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Mechanisms of excitation of spinal networks by stimulation of the ventral roots.

Ann N Y Acad Sci 2010 Jun;1198:63-71

Developmental Neurobiology Section, NINDS, NIH, Bethesda, Maryland, USA.

It has recently been demonstrated that motoneurons in neonatal rodents release an excitatory amino acid, in addition to acetylcholine, from their central terminals onto Renshaw cells. Although the function of this amino acid release is not understood, it may mediate the excitatory actions of motor axon stimulation on spinal motor networks. Stimulation of motor axons in the ventral roots or muscle nerves can activate the locomotor central pattern generator or entrain bursting in the disinhibited cord. Read More

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Reflex responses of masseter muscles to sound.

Clin Neurophysiol 2010 Oct 5;121(10):1690-9. Epub 2010 May 5.

Department of Biomedical Sciences, University of Sassari, Sassari, Italy.

Acoustic stimuli can evoke reflex EMG responses (acoustic jaw reflex) in the masseter muscle. Although these were previously ascribed to activation of cochlear receptors, high intensity sound can also activate vestibular receptors. Since anatomical and physiological studies, both in animals and humans, have shown that masseter muscles are a target for vestibular inputs we have recently reassessed the vestibular contribution to masseter reflexes. Read More

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October 2010

Self-association mediated by the Ras association 1 domain of AF6 activates the oncogenic potential of MLL-AF6.

Blood 2010 Jul 15;116(1):63-70. Epub 2010 Apr 15.

Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.

MLL is a common target for chromosomal translocations associated with acute leukemia resulting in its fusion with a large variety of nuclear or cytoplasmic proteins that may activate its oncogenic properties by distinct but poorly understood mechanisms. The MLL-AF6 fusion gene represents the most common leukemogenic fusion of mixed lineage leukemia (MLL) to a cytoplasmic partner protein. Here, we identified a highly conserved Ras association (RA1) domain at the amino-terminus of AF6 as the minimal region sufficient for MLL-AF6 mediated myeloid progenitor immortalization in vitro and short latency leukemogenesis in vivo. Read More

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Corticospinal contribution to arm muscle activity during human walking.

J Physiol 2010 Mar 1;588(Pt 6):967-79. Epub 2010 Feb 1.

Department of Exercise and Sport Science, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark.

When we walk, our arm muscles show rhythmic activity suggesting that the central nervous system contributes to the swing of the arms. The purpose of the present study was to investigate whether corticospinal drive plays a role in the control of arm muscle activity during human walking. Motor evoked potentials (MEPs) elicited in the posterior deltoid muscle (PD) by transcranial magnetic stimulation (TMS) were modulated during the gait cycle in parallel with changes in the background EMG activity. Read More

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