Abstract
The spontaneously epileptic rat (SER) is a recently bred epileptic animal model which has seizures resembling absence and tonic seisures in humans from two months of age onwards, with similar electroencephalographic characteristics and responses to various antiepileptic drugs.
In this study, local cerebral glucose utilization (LCGU) in SERs and their parent strains, zitter (ZI) and Kyoto/wistar (KW) rats were investigated by the autoradiographic [14C] 2-deoxy-glucose method. LCGU of the 8-week-old SERs which had never exhibited the epileptic seizures was decreased in all brain regions examined, but there were no significant differences in the extent of decrement among those regions, in comparison with KW rats. Moreover, there were no differences in LCGU in all regions examined among both SERs and ZI rats. To the contrary, at 13 weeks of age, the interictal LCGU of SERs which exhibited the epileptic seizures was, on the whole, lower than in the other two strains, and in particular, significantly lower LCGU being found in the hippocampus and amygdala.
In local cerebral blood flow (LCBF) measured using I-125-N-isopropyl-iodoamphetamine, although significantly lower LCBF was found in the amygdala of ZI and SER and in temporal cortex of SER when compared with those of KW, there was no difference in other regions tested among these three strains.
These results suggest that the hippocampus and amygdala are the key structures related to the epileptogenic focus of SERs.
