Electrophysiological Characteristics of the Rubrospinal Neurons in the Nucleus Ruber of the Cat (K Electrofisiologicheskoi Kharakteristike Rubro-Spinalnykh Neironov Krasnogo Yadra Koshki),

The presence of a reflex inhibition in the rubrospinal neurons has been determined by using subthreshold and strict threshold antidromic stimulation. In all tests, the minimum attenuation of the threshold stimulus for the axon of this neuron led to complete disappearance of the antidromic action potential, with no signs of an inhibitory postsynaptic potential. This indicates absence or weak manifestation of a reflex inhibition in the neurons of the necleus ruber during the stimulation of the rubrospinal tract. The dependence found during the investigation of the motor neurons of the spinal cord, according to which reflex inhibition decreases with a decrease in the duration of the subsequent hyperpolarization of an antidromically aroused action potential, was fully confirmed in the experiments. Thus these experiments provide a basis for a classification of the rubrospinal neurons as fast neurons. This obviously plays an important role in providing a rapid and flexible influence of the nucleus rubers on the reflex mechanisms of the spinal cord.