Dependence of impulse reactions in surviving sections of cortex on stimulation parameters

The dependence of neuronal reactions on the location of the stimulating electrode, and the intensity, frequency, and duration of stimulation was investigated in experiments on surviving sections of the neocortex of the guinea pig. The character of the response was maintained in the majority of the neurons only at a slightly suprathreshold intensity of stimulation, a quite low frequency of its presentation (0.1 imp/sec), and a limited duration of the series of stimuli (10-30) with a following 5-10 min break. More intense, high-frequency, or too prolonged stimulation led, as a rule, to a temporary suppression of impulse reactions. Excitation spread more readily in a radial direction, rather than a tangential direction, at identical linear distances to the points of stimulation.