Peptidergic Regulation of Feeding

This chapter focuses on the role of peptides as the regulators of food intake. Peptides, besides acting as neurotransmitters within the central nervous system, can also be released into the bloodstream and circulate, thereby acting as classical hormones. In addition, peptides can be released from nonneuronal cells in the periphery and produce an effect on neighboring cells, which is the so-called paracrine system. It would appear that all three of these modes of action of peptides are involved in the regulation of food intake. To understand the interactions of the multiple neurotransmitters involved in the regulation of feeding, a hypothetical model utilizing a matchstick diagram, from which further experiments can be designed to probe the mysteries of appetite regulation, was developed. The model originally proposed that the hypothalamus acts as a neuroendocrine transducer with the control of food intake involving a balance between a number of neuropeptides and monoamines.