Motoneurons, the final common path of the Central Nervous System (CNS), are under a complex control of its excitability in order to precisely translate the interneuronal pattern of activity into skeletal muscle contraction and relaxation. To fulfill this relevant function, motoneurons are provided with a vast repertoire of receptors and channels, including the extrasynaptic GABAA receptors whic...

Spinal motoneurons possess large, highly branching dendritic structures that contain thousands of synaptic contacts and various voltage-gated ion channels (VGICs). Research has indicated that dendritic arborization and cable properties provide the basis for foundational dendritic processing, which is characterized by direction-dependent signal propagation and location-dependent channel activati...

[PDF] [Full Text] [Abstract] , April , 2011; 105 (4): 1835-1849. J Neurophysiol Brian R. Noga, Dawn M. G. Johnson, Mirta I. Riesgo and Alberto Pinzon receptors in the thoraco-lumbar spinal cord 2b α or NE 1a α with NE Locomotor-activated neurons of the cat. II. Noradrenergic innervation and colocalization [PDF] [Full Text] [Abstract] , October , 2011; 106 (4): 1652-1661. J Neurophysiol Tany...

The state of areflexia and muscle weakness that immediately follows a spinal cord injury (SCI) is gradually replaced by the recovery of neuronal and network excitability, leading to both improvements in residual motor function and the development of spasticity. In this review we summarize recent animal and human studies that describe how motoneurons and their activation by sensory pathways beco...

PURPOSE Too investigate asymmetry in eyelid movements with blinking, the stability of the asymmetry, and its modifiability in normal humans. METHODS Differences in the start time and amplitude between the two eyelids were assessed for voluntary blinks and reflex blinks evoked by supraorbital trigeminal nerve stimulation. These variables were also measured before and up to 18 months after 2 ho...

In brain cortex-ablated cats (BCAC), hind limb motoneurons activity patterns were studied during fictive locomotion (FL) or fictive scratching (FS) induced by pinna stimulation. In order to study motoneurons excitability: heteronymous monosynaptic reflex (HeMR), intracellular recording, and individual Ia afferent fiber antidromic activity (AA) were analyzed. The intraspinal cord microinjections...

Although Substance P (SP) acts primarily through neurokinin 1 (NK1) receptors to increase the excitability of virtually all motoneurons (MNs) tested, the ontogeny of this transmitter system is not known for any MN pool. Hypoglossal (XII) MNs innervate tongue protruder muscles and participate in several behaviors that must be functional from birth including swallowing, suckling and breathing. We...

Background: Spasticity is one of the major neurological complications occurring in people with Spinal Cord Lesions due to loss of supra-spinal and spinal control over alpha motor neuron activity. Its accurate assessment is necessary for tailoring patient specific rehabilitation program. Clinical assessment is commonly done through Modified Ashworth Scale where in the examiner subjectively judge...

Immediately after spinal cord injury (SCI), a devastating paralysis results from the loss of brain stem and cortical innervation of spinal neurons that control movement, including a loss of serotonergic (5-HT) innervation of motoneurons. Over time, motoneurons recover from denervation and function autonomously, exhibiting large persistent calcium currents (Ca PICs) that both help with functiona...