Fig. (7) (p24, Nef) Immunohistochemical demonstration of HIV-1 antigens in frontal lobe neurons of the patient #5 with HAD (the results of staining in patients #1-4 were comparable) (a). Positive neuronal staining with anti p24 (ISF2) (40x, inset 100x). (b) Positive neuronal staining with anti p24 (AG 3.0) (100x). (c) Positive neuronal staining with anti-Nef (AE6). (d) Positive neuronal staining with anti-Nef (EH1).