Thermal Regulation of Spontaneous Spike Frequency and Concomitant Changes in the Amplitude of Spikes from Cortical Neurons

Studies using living slices of guinea pig sensorimotor cortex showed that changes in temperature from 24°C to 37°C produced stepwise increases in neuron spike frequency at two temperature zones: 27–29°C and 34–36°C. Changes in spontaneous activity were accompanied by decreases in spike amplitude at t   34°C. After cooling to 24°C, spike amplitude generally recovered completely when the temperature was increased to 32–34°C. The decrease in spike amplitude at t > 35°C could not be restored by decreasing the temperature. It is suggested that these effects are associated with the K+ permeability of neuron membranes.