Enhancement of synaptic transmission Induced by BDNF in Cultured cortical neurons

摘要

Brain-derived neurotrophic factor (BDNF), like other neurotrophins, has long-term effects on neuronal survival and differentiation; furthermore, BDNF has been reported to exert an acute potentiation of synaptic activity and are critically involved in long-term potentiation(LTP). We found that BDNF rapidly induced potentiation of synaptic activity and an increase in the intracellular Ca~(2+) concentration in cultured cortical neurons. Within minutes of BDNF application to cultured cortical neurons spontaneous firing rate was dramatically increased as were the frequency and amplitude of excitatory spontaneous postsynaptic currents (EPSCs). Fura-2 recordings showed that BDNF acutely elicited an increase in intracellular calcium concentration ([Ca~(2+)]_c). This effect was partially dependent on [Ca~(2+)]_o; The BDNF-induced increase in [Ca~(2+)]_c can not be completely blocked by Ca~(2+)-free solution. It was completely blocked by K252a and partially blocked by Cd~(2+) and TTX. The results demonstrate that BDNF can enhances synaptic transmission and that this effect is accompanied by a rise in [Ca~(2+)]_c that requires two route : the release of Ca~(2+) from intracellular calcium stores and influx of extracellular Ca~(2+) through voltage-dependent Ca~(2+) channels in cultured cortical neurons.