Neuroendocrine Control of Reproduction

Multicellular organisms use a nervous system to sense external (environmental) and internal (e.g. nutritional status) information. The nerve cells summarize and transmit the input information to effector cells using neurotransmitters, which are peptides or small molecules exchanged within synapses. Although these intercellular messages are exchanged quickly, due to rapid intracellular electrical activity, network coverage is limited by the maximum length of a neuron and the intimacy of the cell-cell contact. A more effective means of broadcasting messages involves the neuroendocrine system, which relays information from the nervous system to the rest of the organism. The neuroendocrine system is composed of specialized cells residing in many anatomical locations, sometimes as individual cells or small clusters of a few cells, that receive inputs either directly from the nervous system or from circulating chemicals, integrate these signals, and respond by releasing hormones into circulation to control organismal physiology.