[2 types of neuronal reactions of the medulla oblongata to microstimulation of the locomotor and inhibitory points of the brain stem].

Synaptic responses (postsynaptic potentials and action potentials) of medial and lateral bulbar neurons were evoked by stimulation of the medullary locomotor point (LP) and pontine inhibitory point (IP) by current up to 20 microA in mesencephalic decerebellated cats. Some neurons responded even to single (2-5/s) stimuli. Other neurons responded only to rhythmic (30-60/s) stimulation. Both groups of medial neurons were more susceptible to the input from IP. Lateral neurons which responded even to single stimuli were more reactive to the input from LP, whereas those which responded only to rhythmic stimulation were under the predominant influence from IP. Many neurons (both lateral and medial) with the background activity did not generate responses which were time-locked to a stimulus, however the background activity was either enhanced or inhibited under the rhythmic stimulation. These reactions were encountered more often during stimulation of LP. Partial redistribution of target neurons which accompanied the elevation of the frequency of the presynaptic input may be very significant in the motor control.