Simple and choice reaction time performance in SIV-infected rhesus macaques

Area of Science:

• Neuroscience
• Immunology
• Primatology

Background:

• Human immunodeficiency virus (HIV) infection is linked to motor and cognitive disorders.
• Simian immunodeficiency virus (SIV) infection in rhesus macaques serves as a relevant model for HIV disease in humans.

Purpose of the Study:

• To further establish the SIV-infected rhesus macaque as a model for neuro-AIDS.
• To detect movement-related impairments in SIV-infected macaques using behavioral tasks.

Main Methods:

• Behaviorally trained, SIV-infected rhesus macaques were assessed using simple and choice reaction time tasks.
• Reaction times (RTs), movement times (MTs), and error types were analyzed.
• Nine monkeys were infected with neurovirulent SIVmac; some served as controls initially.

Main Results:

• Rapidly progressing SIV infection (within 4 months) led to slowed reaction times and movement times in most macaques.
• One rapid progressor demonstrated behavioral strategy shifts to compensate for motor deficits.
• Slow progressors also exhibited RT/MT slowing, though non-specific factors were considered.

Conclusions:

• Motor impairments in SIV-infected macaques are detectable via RT and MT measures.
• These findings reinforce the utility of the SIVmac-infected macaque as a viable neuro-AIDS model.
• SIV infection consistently induces behavioral abnormalities indicative of neuronal injury.