Lateralization of catecholaminergic and behavioral response to cerebral infarction in the rat.

The effects of left middle cerebral artery ligation on brain catecholamine concentrations and behavior were compared with those effects of right middle cerebral artery ligation which have previously been reported. Although the lesion caused by middle cerebral artery ligation appeared to be identical on the two sides, the animals with left hemispheric lesion showed no postoperative change in either mean spontaneous 24 hour activity or mean catecholamine concentrations in several areas of the brain. In marked contrast, as we have previously reported and was confirmed in the present study, the animals with a right hemispheric infarct are hyperactive for about 2 to 3 weeks after surgery and there is a significant decrease in mean norepinephrine concentrations in several brain regions. These studies have demonstrated a remarkable asymmetry in the behavioral and biochemical response to cerebral cortical infarction. It is uncertain whether this asymmetry reflects an underlying hemispheric difference in catecholaminergic or non-catecholaminergic neurons.