Age-related behavioural deficits in transgenic mice expressing the HIV-1 coat protein gp120

Transgenic mice expressing HIV-1 coat glycoprotein gp120 in brain glial cel ls were previously shown to display AIDS dementia-like neuropathological ch anges and reduced hippocampal long-term potentiation. In this report, neuro motor and cognitive performance in 3- and 12-month-old gp120-expressing mic e was compared with wildtype controls. Rotarod and cage activity measures s howed no significant differences between transgenic animals and controls of either age. Open field activity was slightly altered in 12-month-old gp120 animals (reduced corner crossings and dwell in centre), but not in the 3-m onth-olds. Cognitive assessment using the Morris water maze showed unimpair ed performance in 3-month-old mice during acquisition and (no-platform) pro be trials. In 12-month-old gp120 animals, escape latency and swimming veloc ity during the acquisition trials were significantly reduced, but performan ce improved at roughly the same rate as in control animals. However, the pr obe trials revealed a highly significant reduction in spatial retention in transgenic mice of this age. This demonstration of age-dependent impairment s in open field activity and spatial reference memory may relate to cogniti ve and neuromotor deficits seen in a proportion of HIV-1-infected individua ls.