Regional cerebral glucose utilization during vasopressin-induced barrel rotations or bicuculline-induced seizures in rats.

Abstract

Regional cerebral metabolic rates of glucose (rCMRglu) were measured in conscious rats grouped according to three treatments: control, bicuculline (5.5 mg/kg s.c.), and intracerebroventricular arginine vasopressin (0.5 micrograms/5 microliter). Rats in the latter group were pre-exposed to the peptide 48 h earlier to render them 100% susceptible to a motor output termed barrel rotation (BR). Marked increases in rCMRglu occurred in all brain areas investigated after bicuculline. Increases after intracerebroventricular arginine vasopressin were smaller and occurred in fewer brain areas. Opposite to bicuculline, arginine vasopressin reduced rCMRglu in hippocampus and auditory cortex. The data confirm marked stimulation of rCMRglu during bicuculline-induced seizures and provide initial data for an endogenous peptide that causes BR. Generalized seizures and BR may share some neural substrates, but they produce distinct changes in rCMRglu. The rCMRglu changes are compatible with the interpretation that BR is initiated by brainstem/cerebellar areas that process visual-vestibular information, with subsequent involvement of higher brain structures.