DECREASED NUMBER OF OXYTOCIN NEURONS IN THE PARAVENTRICULAR NUCLEUS OF THE HUMAN HYPOTHALAMUS IN AIDS

The number of immunocytochemically identified vasopressin (AVP) and ox ytocin (OXT) neurons was determined morphometrically in the paraventri cular nucleus of the hypothalamus of 20 acquired immunodeficiency synd rome (AIDS) patients and 10 controls. The AIDS group consisted of 14 h omosexual males (age range 25-62 years), four of whom had a probable H IV-1 associated dementia complex, and six non-demented heterosexuals ( four males and two females, age range 21 -73 years). Ten males without a primary neurological or psychiatric disease served as a control gro up. The number of OXT-expressing neurons in the paraventricular nucleu s of both groups of AIDS patients was approximately 40% lower than tha t of the controls. In contrast, the three groups showed no significant differences in the number of AVP-expressing neurons in the paraventri cular nucleus. Since there were no significant differences in the numb er of AVP and OXT cells between the homosexual and heterosexual subjec ts with AIDS, the morphological difference in the paraventricular nucl eus seems to be related to AIDS and not to sexual orientation. No infl ammatory changes were found in the paraventricular nucleus area. The s elective changes in the OXT neurons of the paraventricular nucleus may be the basis for part of the neuroendocrine, autonomic dysfunction or vegetative symptoms in AIDS.