Hypothalamic neuropeptides as modulators of neural activity and behaviour

Hypothalamic neural circuits control a diverse array of functions including appetite, arousal, hormone secretion and social behaviour. Many of these functions and behaviours are expressed over long time windows, suggesting that long lasting changes in neural activity are required. Neuropeptides are one class of neuromodulators that are highly expressed in the hypothalamus and are well suited to inducing long-lasting changes in excitability in neural circuits. Here we review the role of hypothalamic neuropeptides in mediating long-lasting changes in neural states. These actions may allow neuropeptides to act as "state controllers" that bridge the gap between transient sensory input and enduring changes in behaviour and neuroendocrine output.