NEURONAL CA2- ACTIVATION AND FUNCTION( STORES )

The intracellular concentration of free Ca2+ ([Ca2+]) displays complex fluctuations in response to a variety of stimuli, and acts as a pluri potent signal for many neuronal functions. It is well established that various 'metabotropic' neurotransmitter receptors can mediate the mob ilization of Ca2+ stores via actions of inositol-polyphosphate second messengers, and move recent evidence suggests that 'ionotropic' recept or-mediated Ca2+ signals in neurones might also involve release of Ca2 + from intracellular stores. These two mechanisms of release of Ca2+ e nable considerable temporal and spatial complexity of increases in the [Ca2+], via multiple interactions at the level of intracellular-recep tor activation. The complexity of Ca2+ signalling that is elicited via these interconnecting pathways might underlie mechanisms that are cen tral to information transfer and integration within neuronal compartme nts.