Abstract:
:We have previously shown that control subjects use two distinct temporal strategies when stepping on an inclined surface during walking: one for level and 10 degrees surfaces and another for 20 and 30 degrees surfaces. These two temporal strategies were characterized by systematic shifts in the timing of muscle activity and peak joint angles. We examined whether cerebellar subjects with mild to moderate gait ataxia were impaired in their ability to select these two temporal strategies, adjust peak joint angle amplitudes, and/or adjust one joint appropriately with respect to movements and constraints at another joint. Subjects walked on a level surface and on different wedges (10, 20, and 30 degrees ) presented in the context of level walking. In a single trial, a subject walked on a level surface in approach to a wedge, took a single step on the wedge, and continued walking on an elevated level surface beyond the wedge. Cerebellar subjects used two temporal strategies, one for the level and 10 degrees surfaces and another for 20 and 30 degrees surfaces. Cerebellar strategies were similar to those used by controls except for the timing of ankle-joint movement on the steeper wedges. Cerebellar subjects adjusted the peak amplitudes of individual joint angles normally, with the exception of peak ankle plantarflexion. However, they exhibited greater trial-to-trial variability of peak hip and knee joint angles that increased as a function of wedge inclination. The most substantial deficit noted in the cerebellar group was in the relative movement of multiple joints. Cerebellar subjects demonstrated multijoint coordination deficits in all conditions, although these deficits were most pronounced during stance on the steeper wedges. On the 30 degrees wedge, cerebellar subjects showed abnormal relative movement of hip, knee, and ankle joints and the most substantial decomposition of movement. We speculate that to simplify multijoint control, cerebellar subjects decomposed their movement by fixing the ankle joint in a dorsiflexed position on the steepest wedges. Our results suggest that the cerebellum may not be critical in selecting the basic motor patterns for the two temporal strategies because cerebellar subjects produced appropriate timing shifts at most joints. Instead, our data suggest that the cerebellum is most critical for adjusting the relative movement of multiple joints, especially to accommodate external constraints.
journal_name
J Neurophysioljournal_title
Journal of neurophysiologyauthors
Earhart GM,Bastian AJdoi
10.1152/jn.2001.85.2.759subject
Has Abstractpub_date
2001-02-01 00:00:00pages
759-69issue
2eissn
0022-3077issn
1522-1598journal_volume
85pub_type
杂志文章abstract::Regularly discharging vestibular-nerve afferents innervating the semicircular canals were recorded extracellularly in anesthetized chinchillas undergoing high-frequency, high-velocity sinusoidal rotations. In the range from 2 to 20 Hz, with peak velocities of 151 degrees/s at 6 Hz and 52 degrees/s at 20 Hz, 67/70 (96%...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1999.82.4.2000
更新日期:1999-10-01 00:00:00
abstract::Synchronization of local and distributed neuronal assemblies is thought to underlie fundamental brain processes such as perception, learning, and cognition. In neurological disease, neuronal synchrony can be altered and in epilepsy may play an important role in the generation of seizures. Linear cross-correlation and ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00368.2010
更新日期:2010-12-01 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::A tool or probe often functions as an extension of the hand, transmitting vibrations to the hand to produce a percept of the object contacting the tool or probe. This paper reports the psychophysical results of a combined psychophysical and neurophysiological study of the perception of vibration transmitted through a ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1999.81.4.1548
更新日期:1999-04-01 00:00:00
abstract::It is well established that patterns of sensory input can affect neuroplastic changes during early development. The scope and consequences of experience-dependent plasticity in the adult are less well understood. We studied the possibility that repeated exposure to trains of stroboscopic stimuli could induce a sensiti...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00724.2005
更新日期:2005-12-01 00:00:00
abstract::Reaching to grasp is of fundamental importance to primate motor behavior and requires coordinating hand preshaping with limb transport and grasping. We aimed to clarify the role of cerebellar output via the magnocellular red nucleus (RNm) to the control of reaching to grasp. Rubrospinal fibers originating from RNm con...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.2001.85.4.1461
更新日期:2001-04-01 00:00:00
abstract::Beyond being essential for long-term motor-skill development, movement repetition has immediate benefits on performance, increasing speed and accuracy of a second execution. While repetition effects have been reported for single reaching movements, it has yet to be determined whether they also occur for movement seque...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00054.2020
更新日期:2020-05-01 00:00:00
abstract::Cellular mechanisms underlying learning and memory were investigated in the octopus using a brain slice preparation of the vertical lobe, an area of the octopus brain involved in learning and memory. Field potential recordings revealed long-term potentiation (LTP) of glutamatergic synaptic field potentials similar to ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00645.2003
更新日期:2003-11-01 00:00:00
abstract::Manipulating a cup by the handle requires compensating for the torque induced by the moment of the mass of the cup relative to the location of the handle. In the present study, we investigated the control strategy of subjects asked to perform grip-lift movements with an object with center of mass located away from the...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00367.2011
更新日期:2011-12-01 00:00:00
abstract::Responses of low characteristic-frequency (CF) neurons in the inferior colliculus were obtained to amplitude-modulated (AM) high-frequency tones in which the modulation rate was equal to the neuron's CF. Despite all spectral components lying outside the pure tone-evoked response areas, discharge rates were modulated b...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00034.2004
更新日期:2004-09-01 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::Frequent gait modifications are often required to navigate our world. These can involve long or wide steps or changes in direction. People generally prefer to minimize the motor cost (or effort) of a movement, although with changes in gait this is not always possible. The decision of when and where to shift gaze is cr...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00027.2019
更新日期:2019-07-01 00:00:00
abstract::Slow covariations in neuronal resting potentials can lead to artefactually fast cross-correlations in their spike trains. J. Neurophysiol. 80: 3345-3351, 1998. A model of two lateral geniculate nucleus (LGN) cells, which interact only through slow (tens of seconds) covariations in their resting membrane potentials, is...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1998.80.6.3345
更新日期:1998-12-01 00:00:00
abstract::When sensory feedback is perturbed, accurate movement is restored by a combination of implicit processes and deliberate reaiming to strategically compensate for errors. Here, we directly compare two methods used previously to dissociate implicit from explicit learning on a trial-by-trial basis: 1) asking participants ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00834.2016
更新日期:2017-08-01 00:00:00
abstract::The present series of investigations was aimed to disclose the possible sites of action of excitatory and inhibitory inputs on tho-interneuron pathway mediating the primary afferent depolarization (PAD) of group I afferents of extensor muscles in the cat spinal cord. To this end we compared the effects produced by sti...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1983.50.4.743
更新日期:1983-10-01 00:00:00
abstract::Behavioral, ethological, and electrophysiological evidence suggests that the highly unpleasant, bitter taste of a concentrated quinine hydrochloride (QHCL) should activate the human amygdala. In the present study, healthy subjects tasted 0.02 M QHCL or water while regional cerebral blood flow (rCBF) was assayed with H...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00358.2001
更新日期:2002-02-01 00:00:00
abstract::The cerebellum has long been recognized to play an important role in motor adaptation. Individuals with cerebellar ataxia exhibit impaired learning in visuomotor adaptation tasks such as prism adaptation and force field learning. Both types of tasks involve the adjustment of an internal model to compensate for an exte...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00654.2011
更新日期:2013-02-01 00:00:00
abstract::1. Physiological responses of hippocampal pyramidal neurons in primary culture to prolonged glutamate (GLU) exposure (500 microM in all experiments) were studied with the use of patch electrodes and whole-cell current-clamp recording techniques. In some experiments, perforated patch recordings were employed with elect...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1992.68.2.362
更新日期:1992-08-01 00:00:00
abstract::A desirable goal of functional MRI (fMRI), both clinically and for basic research, is to produce detailed maps of cortical function in individual subjects. Single-subject mapping of the somatotopic hand representation in the human primary somatosensory cortex (S1) has been performed using both phase-encoding and block...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00499.2012
更新日期:2013-05-01 00:00:00
abstract::One of the fundamental principles of neuroscience is that direct electrical interactions between neurons are not possible without specialized electrical contacts, gap junctions, because the transmembrane resistance of neurons is typically much higher than the resistance of the adjacent extracellular space. However it ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00098.2005
更新日期:2006-03-01 00:00:00
abstract::Behavioral and neural findings demonstrate that animals can locate low-frequency sounds along the azimuth by detecting microsecond interaural time differences (ITDs). Information about ITDs is also available in the amplitude modulations (i.e., envelope) of high-frequency sounds. Since medial superior olivary (MSO) neu...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00044.2013
更新日期:2014-08-15 00:00:00
abstract::Humans with spinal cord injury (SCI) modulate locomotor output in response to limb load. Understanding the neural control mechanisms responsible for locomotor adaptation could provide a framework for selecting effective interventions. We quantified feedback and feedforward locomotor adaptations to limb load modulation...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00604.2009
更新日期:2010-09-01 00:00:00
abstract::Robust auditory perception plays a pivotal function for processing behaviorally relevant sounds, particularly with distractions from the environment. The neuronal coding enabling this ability, however, is still not well understood. In this study, we recorded single-unit activity from the primary auditory cortex (A1) o...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00476.2016
更新日期:2017-02-01 00:00:00
abstract::Voluntary and stimulus-driven shifts of attention can modulate the representation of behaviorally relevant stimuli in early areas of visual cortex. In turn, attended items are processed faster and more accurately, facilitating the selection of appropriate behavioral responses. Information processing is also strongly i...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.01090.2009
更新日期:2010-07-01 00:00:00
abstract::Augmenting (or incremental) responses are progressively growing potentials elicited by 5- to 15-Hz stimulation within the thalamus, cerebral cortex, or by setting into action reciprocal thalamocortical neuronal loops. These responses are associated with short-term plasticity processes in thalamic and cortical neurons....
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1998.79.5.2716
更新日期:1998-05-01 00:00:00
abstract::The effects of neuronal density on morphological and functional attributes of the evolving networks were studied in cultured dissociated hippocampal neurons. Plating at different densities affected connectivity among the neurons, such that sparse networks exhibited stronger synaptic connections between pairs of record...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00914.2009
更新日期:2010-08-01 00:00:00
abstract::We have used a computer-based mathematical model of alpha-motoneurons and of group Ia synaptic input to them, based on anatomical and electrophysiological data from the cat spinal cord, in order to examine the effects of variations in neuron size and input resistance and of conductance magnitude and duration on the ge...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1983.50.2.399
更新日期:1983-08-01 00:00:00
abstract::The input-output and discharge properties of neurons are shaped by both passive and active electrophysiological membrane properties. Whole cell patch-clamp recordings in lamina I-III neurons in an isolated preparation of the whole spinal cord of juvenile rats with attached dorsal roots and dorsal root ganglia were use...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00187.2016
更新日期:2016-09-01 00:00:00
abstract::Express saccades represent the fastest possible eye movements to visual targets with reaction times that approach minimum sensory-motor conduction delays. Previous work in monkeys has identified two specific neural signals in the superior colliculus (SC: a midbrain sensorimotor integration structure involved in gaze c...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00047.2015
更新日期:2015-08-01 00:00:00
abstract::In songbirds, the basal ganglia outflow nucleus LMAN is a cortical analog that is required for several forms of song plasticity and learning. Moreover, in adults, inactivating LMAN can reverse the initial expression of learning driven via aversive reinforcement. In the present study, we investigated how LMAN contribut...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00311.2011
更新日期:2011-10-01 00:00:00