Neural vasopressin is a potent modulator of behaviour in vertebrates. It acts at both sensory processing regions and within larger
regulatory networks to mediate changes in social recognition, affiliation, aggression, communication and other social behaviours.
There are multiple populations of vasopressin neurons within the brain, including groups in olfactory and visual processing
regions. Some of these vasopressin neurons, such as those in the main and accessory olfactory bulbs, anterior olfactory nucleus,
piriform cortex and retina, were recently identified using an enhanced green fluorescent protein-vasopressin (eGFP-VP) transgenic
rat. Based on the interconnectivity of vasopressin-producing and sensitive brain areas and in consideration of autocrine,
paracrine and neurohormone-like actions associated with somato-dendritic release, we discuss how these different neuronal
populations may interact to impact behaviour.