Somato-dendritic secretion of neuropeptides

In addition to classical neurosecretion at the synapse, many neurons also secrete neurotransmitters from their cell bodies and dendrites. In contrast to synaptic transmission, somato-dendritic secretion is best characterized as modulating the overall excitability of the target cells over a longer time course via actions at presynaptic and extrasynaptic receptors. Magnocellular neurons of the hypothalamic supraoptic and paraventricular nuclei synthesize the neuropeptides, vasopressin and oxytocin, and were among the first neurons shown to secrete neurotransmitters from their cell bodies and dendrites by exocytosis. These neuropeptides modulate the activity of the neurons from which they are secreted, as well as the activity of neighboring neurons, to provide intra- and interpopulation signals that coordinate the endocrine and autonomic responses for control of cardiovascular and reproductive physiology, as well as behavior.