Responses of constantly firing motor units to afferent stimulation
- 14 Downloads
Constantly firing motor units of the short abductor muscles of the first finger in the human hand and the abdominal wall muscle in immobilized rats responded to afferent stimulation of the median and sciatic nerves respectively with changes in the nature of spike activity. In the first 250 msec of the post-stimulus period, the frequency of motor unit spike activity became unstable and peri-stimulus histograms were individually quite distinct. This was followed by relative stabilization of motor unit discharge frequencies, and the subsequently (750 msec) determined motor unit spike frequency depended on most cases on the background spike frequency.
Key wordsMotor unit motoneuron afferent stimulation spike frequency
Unable to display preview. Download preview PDF.
- 1.L. P. Kudina, “Testing the excitability of a spiking motoneuron in humans in the interspike interval,” Neirofiziologiya,19, 210–216 (1987).Google Scholar
- 2.L. P. Kudina and L. I. Chirikova, “The frequency ratio of discharges of a spiking motoneuron and the efficiency of excitatory stimulation of 1-a afferents in humans,” Neirofiziologiya,19, 595–600 (1987).Google Scholar
- 3.P. Ashby and D. Zilm, “Characteristics of postsynaptic potentials produced in single human motoneurons by homonymous group,” Vollys. Exp. Brain Res.,47, 41–48 (1982).Google Scholar
- 4.B. A. Conway, H. Hultborn, O. Kiehn, and I. Miutz, “Plateau potentials in a-motoneurons induced by intravenous injection of L-DOPA and clonidine in the spinal cat,” J. Physiol. (London),405, 369–384 (1988).Google Scholar
- 7.J. Hounsgaard, H. Hultborn, B. Jespersen, and O. Kiehn, “Bistability ofa-motoneurons in the decerebrate cat after intravenous 5-hydroxytryptophan,” J. Physiol. (London),405, 345–367 (1988).Google Scholar
- 10.T. S. Miles and K. S. Turker, “Biphasic inhibitory responses and their IPSPs, evoked by tibial nerve stimulation in human soleus,” Exp. Brain Res.,74, 637–645 (1989).Google Scholar