Cerebral energy metabolism in rats with genetic absence epilepsy is not correlated with the pharmacological increase or suppression of spike-wave discharges.
The quantitative [14C]2-deoxyglucose (2-DG) autoradiographic method was applied to measure the effects of pharmacological agents on local cerebral metabolic rates of glucose (LCMRglcs) in a selected strain of Genetic Absence Epilepsy Rats from Strasbourg (GAERS). In a previous study, we have shown that GAERS display an overall significant increase of LCMRglc compared to non-epileptic rats from a selected strain. To further characterize the metabolic responses in GAERS, we measured the effects of drugs aggravating or suppressing absences. The animals were divided into 4 groups, i.e. 2 non-epileptic control groups and 2 GAERS groups. Ten min before the initiation of the 2-DG procedure, both non-epileptic control and epileptic rats received an injection of the same amount of the pharmacological agent, either haloperidol (2 mg/kg) or ethosuximide (200 mg/kg). In the presence of haloperidol, GAERS exhibited almost continuous spike-wave discharges; however, the difference in energy metabolism between GAERS and non-epileptic control rats was abolished and LCMRglcs were similar in all structures of both groups of animals. In GAERS treated with ethosuximide, spike-wave discharges were totally suppressed, whereas rates of energy metabolism remained higher by 31-72% in all structures of epileptic rats compared to their corresponding non-epileptic controls. These data demonstrate a lack of correlation between the occurrence of spike-wave discharges and LCMRglcs and are in favor of normal or decreased ictal metabolism and of increased interictal glucose utilization by the brain in rats with absence epilepsy.
Nehlig
A
A
INSERM U272, Université de Nancy I, France.
Vergnes
M
M
Marescaux
C
C
Boyet
S
S
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D004569:Electroencephalography / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects*; D004832:Epilepsy, Absence / Q000235:genetics / Q000378:metabolism*; D005013:Ethosuximide / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism; D006220:Haloperidol / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D005013:Ethosuximide; D005947:Glucose; D006220:Haloperidol