Voltage-gated calcium channels in adult hippocampal neurons.

Abstract

Interest in how calcium ions move through neuronal membranes and in the function of calcium ions once in the cytoplasm continues to intensify. Calcium ions in the cytoplasm appear to be ubiquitous second messengers that have been implicated in the regulation of numerous intracellular enzymes (Kennedy, 1989) and in gene expression (Morgan and Curran, 1988). Intracellular calcium ions are also essential for neuronal events such as synaptogenesis, neurotransmitter release, and synaptic plasticity (although the mechanisms remain unclear). Moreover, voltage-gated calcium influx is a critical determinant of the electroresponsiveness of neurons either directly (Llinas, 1988) or indirectly through the subsequent activation of potassium, nonselective cation, or chloride permeability changes in the membrane (Marty, 1989).