Abstract:
:1. A method is described for measuring contractile properties of single human motor units. Conventional human microneurographic techniques were adapted to stimulate individual motor axons in the median nerve, with the use of negative current pulses and a tungsten microelectrode, while recording motor-unit electromyographic activity (EMG) and isometric force responses from the thenar muscles. 2. EMG signals were recorded from both proximal and distal thenar muscle surfaces. Force was recorded in two directions (thumb flexion and abduction). This allowed calculation of the direction and magnitude of resultant force exerted by each unit. 3. Data accepted as originating from a single unit satisfied all the traditional "all-or-none" criteria. Additional criteria also required the following: 1) a wide safety margin between the threshold for unit activation and the current intensity needed to elicit responses from other units; 2) that the characteristic direction in which each unit generated force did not change during the recording period; and 3) whenever F-responses were encountered, the second EMG waveform was identical to the first--a highly improbable event if more than one unit had been excited. 4. Respiration and blood pressure waves introduced baseline fluctuations that distorted the force measurements. These fluctuations were minimized by synchronizing stimuli to the pulse pressure cycle and resetting the baseline electronically just before stimulus onset. 5. Combining motor-axon stimulation at a site remote from the muscle with electronic resetting of the force baseline and delivery of stimuli at fixed intervals after the pulse pressure waves allowed the full time course of human motor-unit twitch and tetanic force and EMG signals to be recorded accurately without signal averaging.
journal_name
J Neurophysioljournal_title
Journal of neurophysiologyauthors
Westling G,Johansson RS,Thomas CK,Bigland-Ritchie Bdoi
10.1152/jn.1990.64.4.1331subject
Has Abstractpub_date
1990-10-01 00:00:00pages
1331-8issue
4eissn
0022-3077issn
1522-1598journal_volume
64pub_type
杂志文章abstract::Motor cortex (M1) activity between postnatal weeks 5 and 7 is essential for normal development of the corticospinal tract (CST) and visually guided movements. Unilateral reversible inactivation of M1, by intracortical muscimol infusion, during this period permanently impairs development of the normal dorsoventral dist...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.91026.2008
更新日期:2009-03-01 00:00:00
abstract::During locomotion, contacting an obstacle generates a coordinated response involving flexion of the stimulated leg and activation of extensors contralaterally to ensure adequate support and forward progression. Activation of motoneurons innervating contralateral muscles (i.e., crossed extensor reflex) has always been ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.01274.2007
更新日期:2008-02-01 00:00:00
abstract::The recovery of soleus (SOL), gastrocnemius (GAS), and tibialis anterior (TA) electromyographic activity (EMG) after transection and surgical repair of the sciatic nerve was studied in Sprague-Dawley rats using chronically implanted stimulation and recording electrodes. Spontaneous EMG activity in SOL and GAS and dire...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.01035.2006
更新日期:2007-02-01 00:00:00
abstract::1. Somatic K currents of cultured hippocampal, striatal, and spinal cord neurons of embryonic rat were recorded under voltage clamp in membrane spheres ("blebs") excised by means of a tight-seal pipette. 2. The somatic K current in blebs was subject to rapid and near complete inactivation during 300-ms depolarizations...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1992.68.5.1708
更新日期:1992-11-01 00:00:00
abstract::The problem of how the hippocampus encodes both spatial and nonspatial information at the cellular network level remains largely unresolved. Spatial memory is widely modeled through the theoretical framework of attractor networks, but standard computational models can only represent spaces that are much smaller than t...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00856.2015
更新日期:2016-08-01 00:00:00
abstract::Synaptic dynamics comprise a variety of interacting processes acting on a wide range of time scales. This enables a synapse to perform a large array of computations, from temporal and spatial filtering to associative learning. In this study, we describe how changing synaptic gain via long-term plasticity can act to sh...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00856.2003
更新日期:2004-02-01 00:00:00
abstract::1. Evidence from single-unit recordings suggests that neurons in the medial superior temporal visual area (MST) carry directional signals that influence psychophysical judgements of motion direction. We tested this hypothesis by electrically stimulating clusters of directionally selective neurons in MST (the dorsomedi...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1995.73.2.437
更新日期:1995-02-01 00:00:00
abstract::The magnitude of postsynaptic Ca(2+) transients is thought to affect activity-dependent synaptic plasticity associated with learning and memory. Large Ca(2+) transients have been implicated in the induction of long-term potentiation (LTP), while smaller Ca(2+) transients have been associated with long-term depression ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.2001.85.1.399
更新日期:2001-01-01 00:00:00
abstract::In the inferior colliculus (IC) of the big brown bat, a subpopulation of cells ( approximately 35%) are tuned to a narrow range of sound durations. Band-pass tuning for sound duration has not been seen at lower levels of the auditory pathway. Previous work suggests that it arises at the IC through the interaction of s...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.2000.84.3.1475
更新日期:2000-09-01 00:00:00
abstract::1. In the intact cat eye, the responses of ganglion cells to light stimulation were recorded extracellularly and the actions of iontophoretically applied 2-amino-4-phosphonobutyrate (APB), a potent agonist at ON-bipolars, and of strychnine, a glycine antagonist, were investigated. 2. Under light-adapted conditions, th...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1988.59.6.1657
更新日期:1988-06-01 00:00:00
abstract::During anticipated postural perturbations induced by limb movement, the central nervous system generates anticipatory postural adjustments (APAs) in the trunk and hip musculature to minimize disturbances to equilibrium. Age-related changes in functional organization of the nervous system may contribute to changes in A...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00428.2018
更新日期:2018-12-01 00:00:00
abstract::The ablation of afferent input results in the reorganization of sensory and motor cortices. In the primary visual cortex (V1), binocular retinal lesions deprive a corresponding cortical region [lesion projection zone (LPZ)] of visual input. Nevertheless, neurons in the LPZ regain responsiveness by shifting their recep...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00871.2007
更新日期:2008-05-01 00:00:00
abstract::Synchronous neural oscillations are found throughout the brain and are thought to contribute to neural coding and the propagation of activity. Several proposed mechanisms of synchronization have gained support through combined theoretical and experimental investigation, including mechanisms based on coupling and corre...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00362.2012
更新日期:2012-10-01 00:00:00
abstract::Noninvasive alternating current stimulation can induce vision restoration in patients with chronic optic nerve damage and results in electroencephalogram (EEG) aftereffects. To better understand the mechanisms of action, we studied such EEG "aftereffects" of transcorneal alternating current stimulation (tACS) at the c...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00341.2012
更新日期:2012-11-01 00:00:00
abstract::1. The proton-gated current was investigated in whole-cell configuration of the neurons isolated from bullfrog heart parasympathetic ganglia with the use of the "concentration-clamp" technique, which combines intracellular perfusion and extremely rapid exchange of external solution within 1-2 ms, under a single-electr...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1990.63.5.1060
更新日期:1990-05-01 00:00:00
abstract::1. Intracellular recordings near the output terminals of an identified interneuron (the descending contralateral movement detector, DCMD) in the locust revealed the occurrence of depolarizing synaptic potentials. These presynaptic depolarizing potentials were evoked by spikes in both DCMDs, by auditory stimuli, and by...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1981.45.3.501
更新日期:1981-03-01 00:00:00
abstract::1. In vagotomized, paralyzed, decerebrate cats, simultaneous recordings were taken from one or more sympathetic nerves [cervical sympathetic (CS), inferior cardiac (IC), splanchnic (SP)] and from medullary neurons in vasomotor-related regions. Coherence analyses were used to ascertain the presence of sympathetic rhyth...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1995.74.1.474
更新日期:1995-07-01 00:00:00
abstract::The orthodromic synaptic responses, membrane properties, and responses of dentate gyrus granule cells (DGCs) to several convulsant agents were studied in the in vitro hippocampal slice preparation. Orthodromic stimulation via the perforant pathway (PP) evoked excitatory-inhibitory postsynaptic potentials (EPSP-IPSP) s...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1984.51.2.195
更新日期:1984-02-01 00:00:00
abstract::Spatial and temporal properties of LGN receptive fields were studied by flashing a small bar of light across the field in 28 discrete steps. The flashes at each of the spatial positions were used to produce 28 PST histograms. These histograms were in turn displayed as a plane, with space on the chi axis, time on the p...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1976.39.2.213
更新日期:1976-03-01 00:00:00
abstract::1. Patterns of respiratory neuronal activity were examined in pentobarbitone anesthetized adult cats in a circumscribed area of the ventrolateral medulla, which has previously been defined as the pre-Bötzinger complex (pre-BOTC) from electrophysiological and morphological criteria in the brain stem-spinal cord prepara...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1995.73.4.1452
更新日期:1995-04-01 00:00:00
abstract::The role of dorsal root reflexes (DRRs) in acute cutaneous neurogenic inflammation induced by intradermal injection of capsaicin (CAP) was examined in anesthetized rats. Changes in cutaneous blood flow (flare) on the plantar surface of the foot were measured using a laser Doppler flowmeter, and neurogenic edema was ex...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1999.82.5.2602
更新日期:1999-11-01 00:00:00
abstract::1. The functional organization of interneurons in spinal laminae III-V was studied in an isolated preparation of hamster dorsal horn with sensory innervation from an excised skin patch. Morphological details of 40 neurons were visualized by intracellular injection of horseradish peroxidase. Active and passive membrane...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1992.68.5.1746
更新日期:1992-11-01 00:00:00
abstract::Bladder and erectile dysfunction are common urologic complications of diabetes and are associated with reduced parasympathetic autonomic control. To determine whether disruption of ganglionic neurotransmission contributes to the loss of function, we investigated synaptic transmission at parasympathetic, major pelvic g...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00354.2012
更新日期:2013-02-01 00:00:00
abstract::Understanding how whisker-based tactile information is represented in the nervous system requires quantification of sensory input and observation of neural activity during whisking and whisker touch. Chronic electrophysiological methods have long been available to study neural responses in awake and behaving animals; ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00012.2008
更新日期:2008-07-01 00:00:00
abstract::The primate superior colliculus (SC) is causally involved in microsaccade generation. Moreover, visually responsive SC neurons across this structure's topographic map, even at peripheral eccentricities much larger than the tiny microsaccade amplitudes, exhibit significant modulations of evoked response sensitivity whe...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00077.2020
更新日期:2020-06-01 00:00:00
abstract::Foot drop is very common among people with chronic incomplete spinal cord injury (SCI) and likely stems from SCI that disturbs the corticospinal activation of the ankle dorsiflexor tibialis anterior (TA). Thus, if one can recover or increase the corticospinal excitability reduced by SCI, motor function recovery may be...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00557.2018
更新日期:2019-03-01 00:00:00
abstract::We investigated whether the proprioceptive eye position signal after the execution of a saccadic eye movement is used to estimate the accuracy of the movement. If so, saccadic adaptation, the mechanism that maintains saccade accuracy, could use this signal in a similar way as it uses visual feedback after the saccade....
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00095.2019
更新日期:2019-11-01 00:00:00
abstract::1. Properties of 90 lateral cervical nucleus (LCN) neurons responsive to light tactile stimulation of ipsilateral body surfaces were examined in pentobarbital sodium-anesthetized raccoons. Peripheral receptive fields (RFs) of 60 of these lay totally or partially on glabrous skin of the forepaw. There were 71 neurons a...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1991.65.6.1411
更新日期:1991-06-01 00:00:00
abstract::In quadrupeds, the dorsal-side-up body orientation during standing is maintained due to a postural system that is driven by feedback signals coming mainly from limb mechanoreceptors. In caudally decerebrated (postmammillary) rabbits, the efficacy of this system is considerably reduced. In this paper, we report that th...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00042.2012
更新日期:2012-06-01 00:00:00
abstract::Paw-shake responses (PSRs) were evoked by wrapping masking tape around the hind-paw in nine cats spinalized at the T12 level either at 2 or 12 wk of age or as young adults (10-12 mo). Electromyographic responses of ankle extensors (LG and SOL) and one ankle flexor (TA) were recorded through the 6th mo after cord trans...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1984.51.4.680
更新日期:1984-04-01 00:00:00