Anxiogenic effect of low-dose methamphetamine in the test of elevated plus-maze.

Methamphetamines (MA) are psychostimulant drugs that are known to change individuals' behavior. Psychostimulants could either evoke positive emotions (e.g. joy and happiness) or attenuate negative emotional states (e.g. anxiety and depression) in humans. In animal experiments, the test of elevated plus-maze (EPM) is widely used. This test is appropriate for evaluation of anxiolytic and anxiogenic drug effects, or for examination of specific subtypes of anxiety disorders. The aim of the present study was to examine the effect of acute single dose of MA (1 mg/kg) on the behavior of laboratory rat in the EPM. The detailed ethologic analysis of behavior was performed using a modified protocol based on the study of Fernández Espejo (1997). Our results demonstrated that MA affects rat's behavior in the EPM in the majority of analyzed categories. The present protocol allowed us to determine positive anxiogenic effect of MA.