37 Motoneurons often fire repetitively and for long periods. In sustained voluntary contractions the 38 excitability of motoneurons declines. We provide the first detailed description of the time-course of 39 human motoneuron recovery after sustained activity at a constant discharge rate. We recorded the 40 discharge of single motor units (MUs, n=30) with intramuscular wire electrodes inserted ...

Spinal muscular atrophy (SMA) is a motoneuron disease caused by loss or mutation in Survival of Motor Neuron 1 (SMN1) gene. Recent studies have shown that selective restoration of SMN protein in astrocytes partially alleviates pathology in an SMA mouse model, suggesting important roles for astrocytes in SMA. Addressing these underlying mechanisms may provide new therapeutic avenues to fight SMA...

Motoneuron excitability and muscle spasms are regulated by 1 5-HT2B and 5-HT2C receptor activity. 2 3 Katherine C. Murray, Marilee J. Stephens, Edmund W. Ballou, Charles J. Heckman, 4 and David J. Bennett 5 Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada; Department of Physiology, 6 Northwestern University, Chicago, IL, USA. 7 8 9 Running Title: 5-HT2B receptors on mot...

Sera from patients with Guillain-Barré syndrome (GBS) following Campylobacter jejuni infection have autoantibody to GM1 ganglioside in the acute phase of the illness. There is a strong association between GBS and Penner's serotype 19 (PEN 19) of C. jejuni. The terminal structure of the bacterial lipopolysaccharide is identical to the terminal tetrasaccharide of GM1 ganglioside. Anti-GM1 antibod...

Activation of ankle extensor group Ia muscle spindle or Ib tendon organ afferents during locomotion can prolong and enhance hindlimb extensor motoneuron activity. A growing body of evidence suggests that these group I evoked reflexes not only compensate for a changing environment but also help shape extensor activity during normal, unperturbed locomotion. In this paper we review four mechanisms...