Feline immunodeficiency virus envelope protein (FIVgp120) causes electrophysiological alterations in rats

Close to 20% of the patients infected with the AIDS virus develops neurological deficit; eventhough HIV does not invade neurons. Consistently with the neurological deficit, HIV(+) subjects show abnormalities in brainstem auditory and visual evoked potentials (BSAEP and VEP) and in sleep patterns. The HIV-derived glycoprotein 120 has been postulated as a neurotoxic; therefore, it may be playing a crucial role in the generation of BSAEP and VEP, as well as in sleep disturbances. To study the role of the virus-derived proteins on the development of these electrophysiological signals' alterations, we have used the feline immunodeficiency virus (FIV)-derived gp120 and evaluated the changes in these electrophysiological signals. We employed 15 adult male Sprague-Dawley rats (250-350 g), chronically implanted for evoked potential and sleep recordings. Results showed that the i.c.v. administration of FIVgp120 (5 ng/10 microliter) produces changes in the latency of both cortical auditory evoked potentials (CAEPs) and VEPs and a decrease in both REM sleep and SWS. These data support the notion that FIVgp120 is neurotoxic to the central nervous system of cats and rats and that this protein suffices to cause electrophysiological alterations. In addition, it suggests that a similar effect may be occurring in humans as a result of HIVgp120's neurotoxic effects.