Calcium Signalling In Neurons
Dr Pandey Abhay Kumar
Specialization of cell systems in organism is accompanied with increased role of intracellular signal systems which direct and co-ordinate organized multicellular responses to realize a particular physiological function. Higher organisms possess multiple specialized signalling systems that recognize environmental signals and transform them into intracellular signals. The information meets transduction to appropriate functional elements, perhaps programmed genetically to respond, adapt or suffer derangement. Most of such signalling systems use calcium as second messenger. Calcium mediated signal transduction has acquired complexity through evolution, timing to improve signalling pathways and to establish new communications. Signalling drives excitability and propagation of nervous action potential, and its disruption is responsible for several diseases, including toxic impacts. The significance of Ca2+ signalling in living systems is testified by evolved Ca2+ channel toxins in various animal venoms. Calcium influx from the exterior and calcium release intra-cellularly forms distinct facets for investigation in effects of chemicals and drugs. Most calcium channels contain multiple binding sites for agonists and antagonists. Transduction function of calcium channels accords them high biological, particularly neuro-physiological, significance across space and time of understanding and applications. This article attempts to cover facets of neuronal calcium signalling.