Asymmetry of interhemispheric responses evoked in the prefrontal cortex of the rat

Interhemispheric responses of anesthetized rats were evoked in the prefrontal cortex of both cerebral hemispheres by electric stimulation of the homologous contralateral cortical region. Fatigability of interhemispheric responses to repetitive stimulation was lower in the right prefrontal cortex. Besides, responses recorded in the right hemisphere exhibited greater amplitude increments to double-shock stimulation. No significant differences in rheobase, chronaxie, and threshold current were observed when comparing responsiveness of both prefrontal cortices to single stimuli. Results suggest that brain lateralization in the rat could depend, in part, on synaptic functional asymmetries of the prefrontal cortex.