Plateau potential in distal dendrites of CA1 pyramidal neurons, a controversy of NMDA or calcium spike
【摘要】：正Focal activation of glutamate receptors by fluorescence-guided photolysis of caged glutamate in distal dendrites of hippocampal pyramidal cells triggers plateau-like potentials. Calcium transients produced by plateau potentials were not restricted to the sites of photolysis, but occurred throughout individual distal dendritic compartments, indicating that electrogenesis is mediated primarily by voltage-gated channels. Cadmium but not specific inhibitors of R-, L-, P-, N-, Q-type calcium channels could block plateau potentials. In the presence of APV, accumulation AMPA receptor mediated responses by giving trains of stimulations could not trigger plateau potentials. Moreover, puffing APV and MK.-801 at one end of a long distal dendrite while photolysis of caged glutamate at the other end restricted calcium transient to the photolysis end only. These experiments indicate that NMDA receptors are necessary to trigger the voltage depended channel mediated plateau potentials in distal dendrites of CA1 pyramical neurons.