The hypothalamus: the heart of the brain
I have worked on the hypothalamus, and its neuropeptide systems, for more than 40 years now. Neuropeptides are often spoken of as a class of neurotransmitters, but I have argued that this is, to a first approximation, a lie. Neuropeptides and neurotransmitters are very different signaling systems. Neurotransmitters transmit private messages from one cell to another, a message exchanged at a very specific time and place. Neuropeptides are more akin to hormones; they are released extrasynaptically, can be released independently of electrical activity in response to mobilisation of intracellular calcium, are long lasting and can act at considerable distances from their sites of release. And specific neuropeptides can trigger specific and sustained changes in behaviour. My book ("The heart of the brain: the hypothalamus and its hormones") explores the implications of our emerging understanding of neuropeptides.