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 anddifferentiation; furthermore, BDNF has been reported to exert an acute potentiation of synaptic activity and arecritically involved in long-term potentiation(LTP). We found that BDNF rapidly induced potentiation of synapticactivity and an increase in the intracellular Ca~(2+) concentration in cultured cortical neurons. Within minutes of BDNFapplication to cultured cortical neurons ,spontaneous firing rate was dramatically increased as were the frequency andamplitude of excitatory spontaneous postsynaptic currents (EPSCs). Fura-2 recordings showed that BDNF acutelyelicited an increase in intracellular calcium concentration ([Ca~(2+)]c). This effect was partially dependent on [Ca~(2+)]o; TheBDNF-induced increase in [Ca~(2+)]c can not be completely blocked by Ca~(2+)-free solution. It was completely blocked byK252a and partially blocked by Cd2+ and TTX. The results demonstrate that BDNF can enhances synaptic transmissionand that this effect is accompanied by a rise in [Ca~（2+）]c that requires two route : the release of Ca~(2+) from intracellularcalcium stores and influx of extracellular Ca~(2+) through voltage-dependent Ca2+ channels in cultured cortical neurons.