Many other active peptides and neurotransmitters can be isolated from the hypothalamus (Fig. 1.11) and, in some instances, are co-secreted with the known hypophysiotrophic hormones or are found in neurones that project into the hypothalamus from other parts of the brain. Indeed, the hypothalamus contains a wide variety, and a higher concentration, of neuropeptides and neurotransmitters than any other part of the brain.