Following chronic sacral spinal cord transection in rats the affected tail muscles exhibit marked spasticity, with characteristic long-lasting tail spasms evoked by mild stimulation. The purpose of the present paper was to characterize the long-lasting reflex seen in tail muscles in response to electrical stimulation of the tail nerves in the awake spastic rat, including its development with ti...

Spinal plasticity is thought to contribute to sensorimotor recovery of limb function in several neurological disorders and can be experimentally induced in animals and humans using different stimulation protocols. In healthy individuals, electrical continuous Theta Burst Stimulation (TBS) of the median nerve has been shown to change spinal motoneuron excitability in the cervical spinal cord as ...

The aim of this study was to identify a neurophysiological marker of upper motoneuron involvement in patients with sporadic amyotrophic lateral sclerosis (ALS). For this purpose we evaluated the after-effects of transcranial direct-current stimulation (tDCS) on excitability of the motor cortex of eight ALS patients and eight healthy controls. Healthy controls showed a transient polarity-specifi...

One potential expression of altered motoneuron excitability following a hemispheric stroke is the spontaneous unit firing (SUF) of motor units at rest. The elements contributing to this altered excitability could be spinal descending pathways, spinal interneuronal networks, afferent feedback, or intrinsic motoneuron properties. Our purpose was to examine the characteristics of spontaneous disch...

The spatial and temporal balance of spinal α-motoneuron (αMN) intrinsic membrane conductances underlies the neural output final common pathway for motor commands. Although complete set precise localization αMN K+ channels their respective outward remain unsettled, important channel subtypes have now been documented, including Kv1, Kv2, Kv7, TASK, HCN SK isoforms. Unique kinetics gating paramete...

BACKGROUND Mechanisms of anesthetic-mediated presynaptic inhibition are incompletely understood. Isoflurane reduces presynaptic excitability at the larval Drosophila neuromuscular junction, slowing conduction velocity and depressing glutamate release. Mutations in the Para voltage-gated Na channel enhance anesthetic sensitivity of adult flies. Here, the author examines the role of para in anest...

Amyotrophic lateral sclerosis (ALS) is a devastating paralytic disorder caused by dysfunction and degeneration of motoneurons starting in adulthood. Recent studies using cell or animal models document that astrocytes expressing disease-causing mutations of human superoxide dismutase 1 (hSOD1) contribute to the pathogenesis of ALS by releasing a neurotoxic factor(s). Neither the mechanism by whi...

Observations have been made upon a typical flexor reflex with the aim of disclosing the changes in amount, latency, and temporal configuration of reflex discharge that take place as afferent input is varied from zero to maximal for the band of cutaneous myelinated afferent fibers that extends upward from approximately 6 micro in diameter (group II fibers). Reflex threshold is reached at 6 to 12...

The effect of extracellularly applied electrical fields on neuronal excitability and firing behavior is attributed to the interaction between neuronal morphology and the spatial distribution and level of differential polarization induced by the applied field in different elements of the neuron. The presence of voltage-gated ion channels that mediate persistent inward currents (PICs) on the dend...