ABSTRACT

Neurons at multiple levels of the central nervous system generate specific patterns of sympathetic response that may also contain parasympathetic, endocrine, and somatomotor components. Populations of neurons in the hypothalamus, periaqueductal grey matter, rostral medullary raphe, and the ventrolateral medullary reticular formation generate patterned autonomic responses involving multiple tissues. The hypothalamus can be divided into three longitudinal zones: lateral, periventricular, and medial. The hypothalamus can also be divided into four levels (or zones) along the rostral-to-caudal axis: preoptic, anterior (supraoptic), tuberal, and mammillary. The tuberal zone of the hypothalamus contains the dorsomedial and ventromedial hypothalamic nuclei. The dorsomedial and ventromedial hypothalamic nuclei are also located within the medial hypothalamic zone. As predatory or instrumental aggression evolved into social forms of aggression, mechanisms had to emerge that suitably restrained aggression. Oxytocinergic neurons of the paraventricular nucleus project to ß-endorphin neurons in the arcuate nucleus.