Regional changes in transmitter amino acids during focal and generalized seizures in rats

Measurement of glucose utilization after 20 minutes of seizure activity induced by the systemic administration of convulsants in paralyzed, ventilated rats demonstrates that the initial metabolic activation during kainic acid seizures is confined to the hippocampus. L-allylglycine-induced generalized seizures result in a global metabolic activation, whereas bicuculline seizures in fasted rats have little effect on brain glucose utilization after 20 minutes of seizure activity. Other metabolic changes associated with kainic acid seizures also predominate in the hippocampus, were decreases in the levels of aspartate, glutamate, taurine and glutamine, and an increase in the level of GABA are observed after 20 minutes of seizure activity. L-allylglycine seizures are associated with generalized decreases in regional GABA levels, and increases in regional glutamine levels. Bicuculline-induced changes include increases in hippocampal GABA and taurine levels, and increases in cerebellar glutamine and taurine levels. These changes can be tentatively explained in terms of known biochemical and neurophysiological mechanisms of these convulsants.