Normal cerebrovascular regulatory mechanisms are present in intracerebral neuronal transplants

Local cerebral blood flow and local cerebral glucose utilization were measured using quantitative autoradiography in parallel groups of rats (n = 5-7) which 12-15 weeks previously had undergone limited unilateral ibotenate-induced lesion of the nucleus basalis magnocellularis, followed by implantation into ipsilateral neocortex of primordial basal forebrain cell suspensions. Surviving transplants were visualized by acetylcholinesterase histochemistry. Neither lesion alone nor the presence of a transplant produced significant side-to-side differences in either blood flow or glucose use in any of the 20 brain areas measured. Glucose use within the transplant was independent of the site of implantation. When sited in neocortex, glucose use in the transplant (66 +/- 4 mumol/100 g per min) was significantly lower than in the corresponding contralateral site (113 +/- 3 mumol/100 g per min), whereas when sited in subcortical white matter, glucose use (53 +/- 3 mumol/100 g per min) was significantly higher than in the contralateral side (29 +/- 4 mumol/100 g per min). In the host brain as a whole, the ratio of blood flow to glucose use ipsilateral to the transplant (m = 1.27, r = 0.88) was not significantly different from that of the contralateral side (m = 1.30, r = 0.94). This relationship was also observed within the transplanted tissue itself despite the fact that alkaline phosphatase histochemistry revealed a relative hypervascularization associated with the implantation site.(ABSTRACT TRUNCATED AT 250 WORDS)