Basic fibroblast growth factor-induced seizures in rats

The neurotrophic effects of basic fibroblast growth factor on hippocampal neurons have been well documented. However, the acute effects of basic fibroblast growth factor on hippocampal electrical activities in vivo have not yet been studied. To assess the impact of basic fibroblast growth factor on hippocampal electroencephalographic (EEG) activity, two doses of basic fibroblast growth factor were injected into the right ventral hippocampus of freely moving animals. Unilateral injection of 50 ng of basic fibroblast growth factor into the dentate region of the hippocampus resulted in immediate EEG ictal discharges and behavioral seizures in 7/9 rats. These seizures lasted about 2 h following the injection. Injection of 25 ng of basic fibroblast growth factor into the same sites induced ictal discharges of approximately 60 min duration in 3/7 rats. Injection with heat-inactivated basic fibroblast growth factor into the same sites did not cause any EEG or behavioral modifications. These results suggest that in addition to growth-promoting effects, basic fibroblast growth factor is able to acutely alter the electrical activity of hippocampal neurons and cause seizures.