Neuronal habituation and sensitization in the reticular formation of the rat

Abstract

Plasticity of reticular formation neuronal responses to repetitive sensory stimulation was studied in locally anesthetized paralyzed rats. Eighty-four percent of neuronal responses studied (n = 80) showed either decrement, increment, or increment followed by decrement in responses to repetitive sensory stimulation. Effects of stimulus parameters on neuronal plasticity were similar to effects reported for plasticity of behavioral and neuronal responses in other organisms. Spontaneous activity usually decreased as a result of stimulus repetition, although exceptions were noted. Latency from stimulus onset to first spike discharge increased during the course of stimulus repetition. Dishabituation was evident for many of the units tested, particularly for strong extra stimuli such as tail pinches. No differential location of neurons within the reticular core with respect to characteristics of plasticity was observed.