Subcortical cerebral blood flow and metabolic changes elicited by cortical spreading depression in rat

Changes in cerebral cortical perfusion (CBFLDF), local cerebral blood flow (lCBF) and local cerebral glucose utilization (lCGU) elicited by unilateral cortical spreading depression (SD) were monitored and measured in separate groups of rats anesthetized with alpha-chloralose. CBFLDF was recorded with laser Doppler flowmetry, while lCBF and lCGU were measured by the quantitative autoradiographic [14C]iodoantipyrine and [14C]-2-deoxyglucose methods, respectively. SD elicited a wave of hyperemia after a latency of 2 to 3 min followed by an oligemic phase. Ninety minutes following the onset of SD cortical (frontal, parietal and occipital) lCBF and lCGU were essentially the same as on the contralateral side and in sham-treated rats. However, alteration in the lCBF and lCGU in upper and lower brainstem persisted. The present results demonstrate, for the first time, that long-lasting cerebrovascular and metabolic alterations take place within the subcortical regions following SD. These regions provide an attractive site to integrate observations in man concerning spreading depression and the aura of migraine with the other features of the syndrome.