Acute intrahippocampal infusion of BDNF induces lasting potentiation of synaptic transmission in the rat dentate gyrus

Acute intrahippocampal infusion of BDNF induces lasting potentiation of synaptic transmission in the rat dentate gyrus. J. Neurophysiol. 79: 496-499, 1998. The effect of acute intrahippocampal infusion of brain-derived neurotrophic factor (BDNF) on synaptic transmission in the dentate gyrus was investigated in urethan-anesthetized rats. Medial perforant path-evoked field potentials were recorded in the dentate hilus and BDNF-containing buffer was infused (4 mu l, 25 min) immediately above the dentate molecular layer. BDNF led to a slowly developing increase of the held excitatory postsynaptic potential (fEPSP) slope and population spike amplitude. The potentiation either reached a plateau level at similar to 2 h after BDNF infusion or continued to increase for the duration of experiment; the longest time point recorded was 10 h. Mean increases at 4 h after BDNF infusion were 62.2 and 224% for the fEPSP slope and population spike, respectively. No changes in responses were observed in controls receiving duffer medium only or buffer containing cytochrome C. BDNF-induced potentiation developed in the absence of epileptiform activity in the hippocampal electroencephalogram or changes in recurrent inhibition on granule cells as assessed by paired-purse inhibition of the population spike, We conclude that exogenous BDNF induces a lasting potentiation of synaptic efficacy in the dentate gyrus of anesthetized adult rats.