Generation, propagation and transmission of cellular signals
Information processing in the central nervous system relies on the precise interplay of electrical and chemical signals. Action potential generation, propagation, and the initiating events causing transmitter release from the synaptic terminus are determined by the activity of a variety of ion channels. The transfer of information between neurons and target cells is achieved by chemical transmitter substances crossing the synaptic cleft. Neurotransmitter are accumulated in presynaptic vesicles whose fusion with the cell membrane results in neurotransmitter release [Ionenkanäle]. Binding of these substances to specific receptors embedded in the postsynaptic membrane can exert either electrical or biochemical signals by stimulation of ionotropic or metabotropic receptors, respectively. Activation of ionotropic receptors elicit postsynaptic changes in membrane potential that propagate along the dendrites to the neuronal soma. Transmitter-activated, metabotropic G-protein-coupled receptors [Biogene Amine] cause transient changes of intracellular second messenger concentrations which play a central role in cellular forms of plasticity.