Table 3.

Viral replication in the different sections of the brain

	In situ hybridisation	Env (gp41)	nef Expression
Naïve Macaque
Cerebrum	−ve	−ve	−ve
Midbrain	−ve	−ve	−ve
Brain Stem	−ve	−ve	−ve
Cerebellum	−ve	−ve	−ve
SIVmacC8
Cerebrum	+i	+	+
Midbrain	+i	+	+
Brain Stem	+i	+	+
Cerebellum	+i	+	+
SIVmacJ5
Cerebrum	+i	+	+
Midbrain	+i	+	+
Brain Stem	+i	+	+
Cerebellum	+i	+	+
SIVmac17E-Fr
Cerebrum	+i	+	−ve
Midbrain	+i	+	−ve
Brain Stem	+i	+	−ve
Cerebellum	+i	+	−ve

Evidence of viral replication was shown by in situ hybridisation to detect viral RNA, gp41 (envelope protein) to show evidence of virion assembly, and nef expression to identify productively infected cells. Cerebrum = frontal, parietal, occipital, and temporal lobe sections; Midbrain = thalamus and midbrain sections; Brain stem = pons and medulla oblongata sections; Cerebellum = cerebellum. +ⁱ ISH positive cells present between 0.5 and 6.8 + ve cells/mm². + Immunoreactive cells identified in all sections examined. −ve No immunoreactive cells identified