Regional cerebral metabolic rate for glucose during hyperbaric oxygen-induced convulsions

Hyperbaric oxygen-induced convulsions in awake unrestrained rats are preceded by electrocorticographic changes including paroxysmal electrical discharges (PED). During oxygen induced convulsions, alterations in regional cerebral metabolic rate for glucose (rCMRgl) were autoradiographically measured and compared with rCMRgl results obtained during pre-convulsive periods in an earlier study. Statistically elevated rCMRgl during oxygen-induced convulsions were found in globus pallidus, substantia nigra, limbic structures, and cerebellar cortex. Significant reductions were found largely in auditory structures and cerebral cortex. This pattern of changes in rCMRgl resembles the pattern of changes during successive PED in the absence of overt convulsions. This similarity may indicate that a common sequence of biochemical changes leads to both oxygen-induced pre-convulsive as well as convulsive electrical discharges.