Epidermal growth factor and basic fibroblast growth factor promote the generation of long-term potentiation in the dentate gyrus of anaesthetized rats.

The effects of epidermal growth factor (EGF), basic fibroblast growth factor (bFGF) and nerve growth factor (NGF) on long-term potentiation (LTP) of evoked potential were investigated in the dentate gyrus of anaesthetised rats. Tetanic stimulation of 100 pulses at 100 Hz was applied to induce complete LTP, and stimulation of 20 pulses at 60 Hz was used as a subthreshold stimulation in inducing LTP. Injection of 50 ng EGF, bFGF or NGF into the contralateral ventricle influenced neither the basal amplitude of the population spike nor the LTP induced by the tetanus of 100 pulses at 100 Hz. However, EGF or bFGF, but not NGF, significantly augmented the potentiation induced by the tetanus of 20 pulses at 60 Hz and facilitated the generation of LTP. Moreover, the effect of EGF was dose-dependent in the range 5-500 ng. These results suggest that EGF and bFGF promote the generation process of LTP.