LP-BM5 INFECTION IMPAIRS ACQUISITION, BUT NOT PERFORMANCE, OF ACTIVE-AVOIDANCE RESPONDING IN C57B1 6 MICE/

LP-BM5 murine leukemia virus infection causes an AIDS-like syndrome-mu rine acquired immunodeficiency syndrome-in C57Bl/6 mice and impairs sp atial learning in the Morris water maze without gross motor impairment . We used a shuttle shock-avoidance procedure to examine the effects o f LP-BM5 infection on learning and retention of avoidance behavior. Th irty mice were inoculated with LP-BM5; 30 received vehicle (DMEM) inje ctions. Fifteen LP-BM5 and 15 DMEM mice were trained in avoidance 7 wk after inoculation; retention of the avoidance response was tested 4 w k later. The remaining mice were trained 11 wk after inoculation, In a nimals trained 7 wk after inoculation, the groups performed similarly, with a marginally significant tendency for LP-BM5-infected animals to make more avoidance responses. This group difference was sig nificant when animals were retested at 11 wk. However, LP-BM5 animals trained 11 wk after inoculation made significantly fewer avoidance responses t han controls trained at the same time. We conclude that in later stage s of disease, LP-BM5 impairs response acquisition, but not performance , in the active avoidance procedure. Results extend the use of the LP- BM5-infected mouse as a model of AIDS dementia complex.