Early physiological abnormalities after simian immunodeficiency virus infection

Central nervous system (CNS) damage and dysfunction are devastating consequ ences of HIV infection. Although the CNS is one of the initial targets for HIV infection, little is known about early viral-induced abnormalities that can affect CNS function. Here we report the detection of early physiologic al abnormalities in simian immunodeficiency virus-infected monkeys. The acu te infection caused a disruption of the circadian rhythm manifested by rise s in body temperature, observed in all five individuals between 1 and 2 wee ks postinoculation (p.i.), accompanied by a reduction in daily motor activi ty to 50% of control levels. Animals remained hyperthermic at 1 and 2 month s p.i. and returned to preinoculation temperatures at 3 months after viral inoculation. Although motor activity recovered to baseline values at I mont h p.i., activity levels then decreased to approximately 50% of preinoculati on values over the next 2 months. Analysis of sensory-evoked responses I mo nth p.i. revealed distinct infection-induced changes in auditory-evoked pot ential peak latencies that persisted at 3 months after viral inoculation. T hese early physiological abnormalities may precede the development of obser vable cognitive or motor deficiencies and can provide an assay to evaluate agents to prevent or alleviate neuronal dysfunction.