Persistent sodium conductance contributes to orexin-A-mediated modulation of membrane excitability in neonatal rat mesencephalic V neurons

Characteristics of Sensory Neuron Dysfunction in Amyotrophic Lateral Sclerosis (ALS): Potential for ALS Therapy

“…MesV neurons are proprioceptive sensory neurons that control mastication [35,96]; these directly affect motor neurons through α-amino-3-hydroxy-5-methyl-4isoxazolepropionic acid and N-methyl-D-aspartate (NMDA) receptors, which are excitatory postsynaptic receptors for neurotransmitters [97,98]. A study using neonatal ALS model mice (SOD1G93A) reported firing inhibition as an electrophysiological feature of the MesV in neonates [35] (Table 3).…”

“…MesV neurons are proprioceptive sensory neurons that are required for mastication that not only transmit intrinsic sensations from muscle spindles in jaw movements to the centre, but also directly act on trigeminal motor neurons to control masticatory movements [35,[96][97][98]. Treatment strategies for mastication disorders in ALS may focus on protecting the survival and function of the MesV, which controls mastication movements [35,36,[140][141][142].…”

“…In addition, the burst frequency increases in neurons that exhibit rhythmic burst discharges in response to maintained current injections, and NPY treatment increases the Na current in the MesV [139]. Future studies should investigate whether neuropeptides that act in an excitatory capacity on neurons, such as NPY and Orexin, ameliorate the hypo-excitation of the MesV in ALS and improve MesV function [96]. Whether correcting abnormalities in proprioceptive sensory neurons involved in muscle spindles, such as the MesV, corrects mastication deficits in ALS and helps to treat movement disorders in patients with ALS should also be examined [95] (Figure 3).…”