Abstracts

RATIONALE: Injection of [gamma]-butyrolactone (GBL)(100mg/kg) induces absence seizures in rats. Rats fed a ketogenic diet experience fewer and briefer episodes of the spike-wave discharges (SWD) that characterize absence seizures but, unlike those fed a normal diet, demonstrate a profound lethargy. The purpose of this study was to evaluate the lethargic response of male and female rats to injection (i.p.) of GBL.
METHODS: Thirty-four Sprague-Dawley rats of each gender were used and doses of 50, 75, 100 and 125 mg/kg were administered. Some animals received repeated doses in this ascending series and others received only one dose of GBL and and were injected with saline as control in place of the other doses. Rats were scored for posture, gait and performance on a roto-rod.
RESULTS: The higher doses (100 and 125 mg/kg) produced a pronate resting posture, lack of spontaneous mobility and increased failure on the roto-rod behavioral test in rats fed the ketogenic diet but not in those fed standard rodent chow. In ketogenic animals, all of these effects were more evident in females than in males, and all were diminished in both genders if individual animals received repeated injections of GBL.
CONCLUSIONS: Although the ketogenic diet is uniqure in protecting against both convulsive and non-convulsive seizures, ketogenic rats suffer a cognitive/locomotor deficit when injected with ictogenic doses of GBL and this effect is more pronounced in females than in males.
[Supported by: Department of Biology, Georgetown University]