Secreted polyprotein that is packaged and proteolytically processed by prohormone convertases PCSK1 and PCSK2 in a cell-type-specific manner (By similarity). VGF and peptides derived from its processing play many roles in neurogenesis and neuroplasticity associated with learning, memory, depression and chronic pain (By similarity). Plays a role in the control of body fluid homeostasis by regulating vasopressin release. Suppresses presynaptic glutamatergic neurons connected to vasopressin neurons. Plays a role in the control of body fluid homeostasis by regulating vasopressin release. Activates GABAergic interneurons which are inhibitory neurons of the nervous system and thereby suppresses presynaptic glutamatergic neurons (By similarity). Stimulates also feeding behavior in an orexin-dependent manner in the hypothalamus (By similarity). Functions as a positive regulator for the activation of orexin neurons resulting in elevated gastric acid secretion and gastric emptying (By similarity). Stored in secretory vesicles and then secreted, NERP peptides colocalize with vasopressin in the storage granules of hypothalamus. Multiple peptides are derived from VGF, with activities in synaptic plasticity, antidepression, penile erection, autonomic activation, and increases in energy expenditure.