Lateralized response to cortical injury in the rat: interhemispheric interaction.

This study was conducted to investigate the role of interhemispheric interaction in the production of spontaneous hyperactivity following right but not left frontal cortical suction lesions in the rat. Bilateral lesions, either simultaneous or left followed 1 week later by right, led to spontaneous hyperactivity and bilateral depletions of cortical norepinephrine concentrations. Rats given corpus callosum sectioning as neonates and frontal cortical suction lesions as adults developed spontaneous hyperactivity only when the right hemisphere was injured. These data suggest that lateralized spontaneous hyperactivity as elicited by small suction lesions of the right hemisphere does not depend on interhemispheric release or interaction and that at least the cortical mechanism is in the right hemisphere itself.