the rostral portion of the hypothalamus generally located internal to the region of the optic chiasm; contains the following nuclei: anterior hypothalamic nucleus [TA] (nucleus anterior hypothalami [TA]), anterior periventricular nucleus [TA] (nucleus periventricularis ventralis [TA]), interstitial nuclei of anterior hypothalamus [TA] (nuclei interstitiales hypothalami anteriores [TA]), lateral preoptic nucleus [TA] (nucleus preopticus lateralis [TA]), medial preoptic nucleus [TA] (nucleus preopticus medialis [TA]), median preoptic nucleus [TA] (nucleus preopticus medianus [TA]), paraventricular nucleus [TA] (nucleus paraventricularis hypothalami [TA]), periventricular preoptic nucleus [TA] (nucleus preopticus periventricularis [TA]), suprachiasmatic nucleus [TA] (nucleus suprachiasmaticus [TA]), and supraoptic nucleus [TA] (nucleus supraopticus [TA]). The latter cell group consists of dorsomedial, ventromedial, and dorsolateral parts.hypothalamus. SYN: area hypothalamica rostralis [TA], anterior hypothalamic region*.