Hypothalamic synaptogenesis and its relationship with the maturation of hormonal secretion.

1. Information obtained during the last decade has demonstrated that hypothalamic neurons release a wide variety of neuroactive substances, such as neurotransmitters, mostly monoamines and amino acids, and neuromodulators such as the peptides vasopressin (AVP) and oxytocin (OXT) and hypophysial releasing hormones. 2. Synapse formation between hypothalamic neurons was followed at different times within a given nucleus and among different nuclei during development of the mouse hypothalamus. 3. The amounts of various neurotransmitters and hormones were determined at various stages of development. 4. A correlation is presented of the biochemical and ultrastructural features and their functional implications during maturation.