Abstract:
:The aim of this study was to investigate how maximal intermittent contractions for a hand muscle influence cortical and reflex activity, as well as the ability to voluntarily activate, the homologous muscle in the opposite limb. Twelve healthy subjects (age: 24 ± 3 years, all right hand dominant) performed maximal contractions of the dominant limb first dorsal interosseous (FDI), and activity of the contralateral FDI was examined in a series of experiments. Index finger abduction force, FDI EMG, motor evoked potentials and heteronomous reflexes were obtained from the contralateral limb during brief non-fatiguing contractions. The same measures, as well as the ability to voluntarily activate the contralateral FDI, were then assessed in an extended intermittent contraction protocol that elicited fatigue. Brief contractions under non-fatigued conditions increased index finger abduction force, FDI EMG, and motor evoked potential amplitude of the contralateral limb. However, when intermittent maximal contractions were continued until fatigue, there was an inability to produce maximal force with the contralateral limb (~30%) which was coupled to a decrease in the level of voluntary activation (~20%). These declines were present without changes in reflex activity, and regardless of whether cortical or motor point stimulation was used to assess voluntary activation. It is concluded that performing maximal intermittent contractions with a single limb causes an inability of the CNS to maximally drive the homologous muscle of the contralateral limb. This was, in part, mediated by mechanisms that involve the motor cortex ipsilateral to the contracting limb.
journal_name
J Neurophysioljournal_title
Journal of neurophysiologyauthors
Kavanagh JJ,Feldman MR,Simmonds MJdoi
10.1152/jn.00367.2016subject
Has Abstractpub_date
2016-11-01 00:00:00pages
2272-2280issue
5eissn
0022-3077issn
1522-1598pii
jn.00367.2016journal_volume
116pub_type
杂志文章abstract::In this study, the juxtamembrane region of the Drosophila SNARE protein neuronal-Synaptobrevin (n-Syb) was tested for its role in synaptic transmission. A transgenic approach was used to express n-Syb mutant genes. The transgenes carried engineered point mutations that alter the amino acid sequence of the conserved tr...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00474.2013
更新日期:2014-09-15 00:00:00
abstract::The nucleus tractus solitarii (nTS) is the initial central termination site for visceral afferents and is important for modulation and integration of multiple reflexes including cardiorespiratory reflexes. Glutamate is the primary excitatory neurotransmitter in the nTS and is removed from the extracellular milieu by e...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.01054.2015
更新日期:2016-03-01 00:00:00
abstract::In the auditory system of the big brown bat (Eptesicus fuscus), paired conditioned tonal (CS) and unconditioned leg stimuli (US) for auditory fear conditioning elicit tone-specific plasticity represented by best-frequency (BF) shifts that are augmented by acetylcholine, whereas unpaired CS and US for pseudoconditionin...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00930.2011
更新日期:2013-02-01 00:00:00
abstract::A description of healthy and pathological brain dynamics requires an understanding of spatiotemporal patterns of neural activity and characteristics of its propagation between interconnected circuits. However, the structure and modulation of the neural activation maps underlying these patterns and their propagation re...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00708.2011
更新日期:2012-07-01 00:00:00
abstract::Manipulations of vagal activity are used to treat medical pathologies, but the underlying CNS changes caused by these treatments are not well understood. Furthermore, heart and lung transplant as well as treatments for many gastrointestinal disorders result in section of the vagus nerve (vagotomy). Following unilatera...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00168.2009
更新日期:2009-11-01 00:00:00
abstract::The interstitial nucleus of Cajal (INC) is thought to control torsional and vertical head posture. Unilateral microstimulation of the INC evokes torsional head rotation to positions that are maintained until stimulation offset. Unilateral INC inactivation evokes head position-holding deficits with the head tilted in t...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.90363.2008
更新日期:2008-09-01 00:00:00
abstract::This study investigated how the ability to extend the fingers and thumb recovers early after stroke and how the ability to extend all of the digits affects grasping performance. We studied 24 hemiparetic patients at 3 and 13 wk post stroke. At each visit, we tested the subjects' ability to actively extend all five dig...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.91310.2008
更新日期:2009-07-01 00:00:00
abstract::We have used the rat hippocampal slice preparation as a model system for studying the epileptogenic consequences of a reduction in neuronal Na+-K+ pump activity. The cardiac glycosides (CGs) strophanthidin and dihydroouabain were used to inhibit the pump. These drugs had readily reversible effects, provided they were ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1987.57.2.496
更新日期:1987-02-01 00:00:00
abstract::1. Noxious stimuli have been shown to produce a diffuse inhibition of nociresponsive neurons in the spinal and trigeminal dorsal horns. The present study sought to extend these electrophysiological studies of diffuse noxious inhibitory controls (DNIC) by determining the effect of a spatially remote noxious stimulus on...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1994.72.3.1152
更新日期:1994-09-01 00:00:00
abstract::N-methyl-d-aspartate (NMDA) receptors play crucial roles in glutamate-mediated synaptic transmission and plasticity and are involved in a variety of brain functions. Specific single nucleotide polymorphisms (SNPs) in the genes encoding NMDA receptor subunits have been associated with some neuropsychiatric disorders in...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00318.2011
更新日期:2011-10-01 00:00:00
abstract::The cholinergic system is critically involved in synaptic models of learning and memory by enhancing dendritic [Ca(2+)](i) signals. Diffuse cholinergic innervation suggests subcellular modulation of membrane currents and Ca(2+) signals. Here we use ion-selective microelectrodes to study spread of carbachol (CCh) after...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1999.82.4.1909
更新日期:1999-10-01 00:00:00
abstract::Extensive work on learning in reaching and pointing tasks has demonstrated high degrees of plasticity in our ability to optimize goal-directed motor behavior. However, studies focusing on the perceptual awareness of our own actions during motor adaptation are still rare. Here we present the first simultaneous investig...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00104.2006
更新日期:2006-09-01 00:00:00
abstract::Fast oscillatory activity (more than approximately 200 Hz) has been attracting increasing attention regarding its possible role in both normal brain function and epileptogenesis. Yet, its underlying cellular mechanism remains poorly understood. Our prior investigation of the phenomenon in rat somatosensory cortex indi...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.2002.88.2.1016
更新日期:2002-08-01 00:00:00
abstract::1. In taste neurophysiology, from Pfaffmann's (49, 50) pioneering work until the present, the possibility of types of neurons corresponding in some sense with the "primary" taste qualities of Henning (33) has been entertained: recently types of gustatory neurons in peripheral nerves have been established according to ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1979.42.5.1390
更新日期:1979-09-01 00:00:00
abstract::Although G-protein-coupled (metabotropic) receptors are known to modulate the production of motor patterns, evidence from the escape swim central pattern generator (CPG) of the nudibranch mollusk, Tritonia diomedea, suggests that they might also participate in the generation of the motor pattern itself. The dorsal swi...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.2001.85.1.476
更新日期:2001-01-01 00:00:00
abstract::Acetic acid applied to the hind limb of a frog evokes nocifensive behaviors, including a vigorous wiping of the exposed skin, referred to as the wiping response. The aim of this study was to examine the responses of cutaneous primary afferent fibers in frogs to acetic acid (pH 2.84-1.42) applied topically to the skin....
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00324.2003
更新日期:2003-08-01 00:00:00
abstract::Contact-evoked changes in EMG activity during human grasp. 2215 Cutaneous receptors in the digits discharge bursts of activity on contact with an object during human grasp. In this study, we investigated the contribution of this sensory activity to the responses of muscles involved in the task. Twelve subjects perform...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1999.81.5.2215
更新日期:1999-05-01 00:00:00
abstract::Pyramidal cells in the dorsal cochlear nucleus (DCN) show three characteristic discharge patterns in response tones: pauser, buildup, and regular firing. Experimental evidence suggests that a rapidly inactivating K+ current (I(KIF)) plays a critical role in generating these discharge patterns. To explore the role of I...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.2001.85.2.523
更新日期:2001-02-01 00:00:00
abstract::Postembryonic developmental changes in electrophysiological properties of the AIY interneuron class were investigated using whole cell voltage clamp. AIY interneurons displayed an increase in cell capacitance during larval development, whereas steady-state current amplitude did not increase. The time course of the out...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00052.2006
更新日期:2006-06-01 00:00:00
abstract::Respiratory depression is a therapy-limiting side effect of opioid analgesics, yet our understanding of the brain circuits mediating this potentially lethal outcome remains incomplete. Here we studied the contribution of the rostral ventromedial medulla (RVM), a region long implicated in pain modulation and homeostati...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00563.2012
更新日期:2012-11-01 00:00:00
abstract::We performed a whole-body mapping study of the effect of unilateral muscle vibration, eliciting spindle Ia firing, on the control of standing and walking in humans. During quiet stance, vibration applied to various muscles of the trunk-neck system and of the lower limb elicited a significant tilt in whole body postura...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00764.2006
更新日期:2007-01-01 00:00:00
abstract::Spontaneous synchronized bursts of activity play an essential role in the maturation and plasticity of neuronal networks. To investigate the cellular properties that enable spontaneous network activity, we used dissociated cultures of hippocampal neurons that express prolonged network activity bursts. Acute exposure t...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.91085.2008
更新日期:2009-04-01 00:00:00
abstract::In common with other sensory cortices, the mammalian primary auditory cortex (AI) demonstrates the capacity for large-scale reorganization following many experimental situations. For example, training animals in frequency-discrimination tasks has been shown to result in an increase in cortical frequency representation...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.2001.86.4.1555
更新日期:2001-10-01 00:00:00
abstract::When identical stimuli are presented in rapid temporal succession, neural responses to the second stimulation are often weaker than those observed for the first. This phenomenon is termed sensory gating and is believed to be an adaptive feature that helps prevent higher-order cortical centers from being flooded with u...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00260.2017
更新日期:2017-10-01 00:00:00
abstract::Many neurophysiological experiments involving monkeys require that the head be stabilized while the animal performs a task. Often a post is attached to the skull to accomplish this goal, using a headcap formed from dental acrylic. We describe a new headpost, developed by refinement of several prototypes, and supply an...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00102.2007
更新日期:2007-08-01 00:00:00
abstract::We present a quantitative analysis of the visual response properties of single neurons in the dorsal lateral geniculate nucleus (dLGN) of wild-type C57Bl/6J mice. Extracellular recordings were made from single dLGN cells in mice under halothane and nitrous oxide anesthesia. After mapping the receptive fields (RFs) of ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00699.2003
更新日期:2003-12-01 00:00:00
abstract::Dual whole-cell patch clamp recordings from the soma and dendrites of CA1 pyramidal neurons located in hippocampal slices of adult rats were used to examine the potential mechanisms of phase precession. To mimic phasic synaptic input, 5-Hz sine wave current injections were simultaneously delivered both to the soma and...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.2001.86.1.528
更新日期:2001-07-01 00:00:00
abstract::The century-old duplex theory of sound localization posits that low- and high-frequency sounds are localized with two different acoustical cues, interaural time and level differences (ITDs and ILDs), respectively. While behavioral studies in humans and behavioral and neurophysiological studies in a variety of animal m...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00062.2015
更新日期:2015-07-01 00:00:00
abstract::Previous studies examining the influence of afferent stimulation on corticospinal excitability have demonstrated that the intensity of afferent stimulation and the nature of the afferents targeted (cutaneous/proprioceptive) determine the effects. In this study, we assessed the effects of whole-hand water immersion (WI...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00161.2014
更新日期:2015-02-01 00:00:00
abstract::We have shown previously that in the acutely spinalized anesthetized rat the activities of many dorsal horn interneurons (DHN) at the T(10) level are correlated positively with both ongoing and stimulus-evoked renal sympathetic nerve activity (RSNA) and therefore may belong to networks generating RSNA after acute, cer...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.2000.83.5.2699
更新日期:2000-05-01 00:00:00