Behavioral and neurophysiological hallmarks of simian immunodeficiency virus infection in macaque monkeys

Macaque monkeys infected with various neurovirulent forms of simian immunodeficiency virus (SIV) represent highly effective models, not only of systemic acquired immunodeficiency virus (AIDS), but also neuroAIDS. Behavioral studies with this model have clearly established that SIV-infected monkeys show both cognitive and motor impairments resembling those that have been reported in human immunodeficiency virus (HIV)-infected humans. This paper combines data from a number of behavioral studies in SIV-infected macaque monkeys to obtain an overall estimate of the frequency of impairments in various motor and cognitive domains. The results were then compared to similar data from studies of HIV-infected humans. Whereas cognitive functions are most commonly impaired in HIV-infected humans, motor function is the domain most commonly impaired in SIV-infected monkeys. Electrophysiological studies in SIV-infected macaques have revealed deficits in motor-, somatosensory-, visual-, and auditory-evoked potentials that also resemble abnormalities in human HIV infection. Abnormalities in motor-evoked potentials were among the most common evoked potential deficits observed. Although differences in behavioral profiles of human HIV disease and SIV disease in monkeys exist, the results, nevertheless, provide strong validation for the use of macaque models for translational studies of the virology, immunology, pathophysiology, and treatment of neuroAIDS.