Regulation of Voltage-Sensitive Calcium Channels in Brain by Micromolar Affinity Benzodiazepine Receptors
Ca2+ is an important mediator of molecular events in the functioning nerve terminal (1, 2). An increase in cytoplasmic Ca2+ has been shown to regulate a variety of neuronal cell functions, including neurotransmitter release, stimulation of protein phosphorylation, and synaptic morphological changes (3). It is well-established that these events are directly dependent on the entry of extracellular Ca2+ into the presynaptic nerve terminal through specific voltage-gated Ca2+ channels (4,6). The central role of Ca2+ channels in stimulus-secretion coupling mechanisms has led to the extensive investigation of Ca2+ channel function in a wide variety of intact and broken cell preparations (7). Despite extensive electrophysiological characterization of Ca2+ channels in brain, the molecular nature and pharmacological characteristics of this major neuronal Ca2+ channel remain largely unclear.
KeywordsCobalt Manganese Norepinephrine Diazepam Acetylcholine
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