Expression of HIV gp120 protein increases sensitivity to the rewarding properties of methamphetamine in mice.

Methamphetamine abuse and human immunodeficiency virus (HIV) infection induce neuropathological changes in corticolimbic brain areas involved in reward and cognitive function. Little is known about the combined effects of methamphetamine and HIV infection on cognitive and reward processes. The HIV/gp120 protein induces neurodegeneration in mice, similar to HIV-induced pathology in humans.

Predator odor-induced conditioned fear involves the basolateral and medial amygdala.

The basolateral (BLA) and medial nucleus (MeA) of the amygdala participate in the modulation of unconditioned fear induced by predator odor. However, the specific role of these amygdalar nuclei in predator odor-induced fear memory is not known. Therefore, fiber-sparing lesions or temporary inactivation of the BLA or MeA were made either prior to or after exposure to cat odor, and conditioned contextual fear behavior was examined the next day.

The rat exposure test: a model of mouse defensive behaviors.

In order to facilitate behavioral, and potentially pharmacological, analyses of risk assessment behaviors in mice, a rat exposure test (RET) was devised and evaluated. This test provides a home chamber connected via a tunnel to a rat (predator) exposure area. Familiar substrate is provided to permit burying, and mouse subjects are habituated to the apparatus prior to exposure to an amphetamine-activated rat.