Amphetamine-Induced Locomotion and Brain Stimulation Reward Research and Applications

Abstract

Amphetamine, a dopamine agonist, has an effect on increasing dopamine level in certain brain regions, like the nucleus accumben and the ventral tegmental area (Yoshida et al., 1992). Hence, it increases reward-related functions. In the current study, we examined the changes in the frequency of locomotion in previously habituated mice after 3mg/kg amphetamine injections. In the same way, we also monitored the changes in bar pressing rates of previously trained rates after 2mg/kg amphetamine injections. Though not showing a significant statistical result, both graphs and discussions supported that amphetamine injection increased horizontal quadrants crossings compared with saline injection. While the amphetamine administration increased bar press rate in previously trained rats at low frequencies, it led the rats to fewer bar presses at higher frequencies compared with both the baseline and the saline condition. The results of both experiments consistent with past studies which claim that amphetamine acts as a dopaminergic agonist and increases reinforcing capacity through enhancement of dopaminergic transmission (Gallistel & Karras, 1984).