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STUDY OBJECTIVES Sleep has been hypothesized to globally reduce synaptic strength. However, recent findings suggest that in the context of learning and memory consolidation, sleep may promote synaptic potentiation. We tested the requirement for sleep in a naturally occurring form of experience-dependent synaptic potentiation in the adult mouse visual cortex(More)
The objective of this preliminary study was to examine the possible contribution of disordered control of motor unit (MU) recruitment and firing patterns in muscle weakness post-stroke. A novel surface EMG (sEMG) recording and decomposition system was used to record sEMG signals and extract single MU activities from the first dorsal interosseous muscle(More)
We introduce a new method to examine the spinal motoneuron involvement after stroke using a surface electromyography (EMG) recording system. Fourteen chronic stroke survivors with mild to severe muscle weakness participated in the study. Surface EMG signals were collected from the first dorsal interosseous muscle while subjects performed isometric index(More)
Hemispheric brain injury resulting from a stroke is often accompanied by muscle weakness in limbs contralateral to the lesion. In the present study, we investigated whether weakness in contralesional hand muscle in stroke survivors is partially attributable to alterations in motor unit activation, including alterations in firing rate modulation range. The(More)
OBJECTIVE The advancement of surface electromyogram (sEMG) recording and signal processing techniques has allowed us to characterize the recruitment properties of a substantial population of motor units (MUs) non-invasively. Here we seek to determine whether MU recruitment properties are modified in paretic muscles of hemispheric stroke survivors. (More)
The after hyperpolarization (AHP) of a motoneuron is a primary determinant of motoneuron firing rate. Any increase in its duration or amplitude could alter normal motor unit (MU) firing rate properties in stroke, and potentially impact muscle force generation. The objective of this preliminary study was to examine potential differences in(More)
OBJECTIVE Hemispheric stroke survivors often show impairments in voluntary muscle activation. One potential source of these impairments could come from altered control of muscle, via disrupted motor unit (MU) firing patterns. In this study, we sought to determine whether MU firing patterns are modified on the affected side of stroke survivors, as compared(More)
28 29 30 Hemispheric brain injury resulting from a stroke is often accompanied by muscle weakness in 31 limbs contralateral to the lesion. In the present study, we investigated whether weakness in 32 contralesional hand muscle in stroke survivors is partially attributable to alterations in motor unit 33 activation, including alterations in firing rate(More)
We examined surface electromyogram (EMG) characteristics during voluntary isometric activation of the first dorsal interosseous (FDI) muscle in stroke survivors. Five stroke subjects participated in the study. They were instructed to generate isometric contraction at different force levels. The recording was performed in both paretic and contralateral(More)
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