[Multi-component synaptic potentials of rubrospinal neurons of the cat induced by corticofugal spike trains].

Compound nature of EPSPs in rubrospinal neurons evoked by stimulation of the sensorimotor and associative parietal region of the cerebral cortex was shown in acute experiments on nembutalized cats by means of intracellular technique. Monosynaptic nature of the first two components of EPSPs evoked by corticofugal impulses propagating with an average velocity of 18.5 m/s and 7.5 m/s was revealed. These components are supposed to arise as a result of activation of slow conducting pyramidal and corticorubral neurons. In some rubrospinal neurons the first EPSP component evoked by corticofugal impulsation had a fast rising phase and reflected activation of axo-somatic synapses. The results are discussed in the light of the mechanisms of reorganization of cortical synaptic inputs to the red nucleus neurons.