Behavioral observation and intracerebral electrochemical recording following administration of amphetamine in rats

Abstract

Intracerebral electrochemistry (chronoamperometry) was performed on rats that were administered 1, 4, and 8 mg/kg doses of amphetamine. Graphpoxy working electrodes were implanted bilaterally in nucleus accumbens (ACC) and ventral anterior striatum (VAS). Following drug injection, locomotor and stereotyped behaviors were observed. Intracerebral electrochemical signals reliably increased following injection of amphetamine. The magnitude of these increases did not change significantly across the dose range tested for VAS electrodes. ACC electrodes had increases similar in magnitude to VAS electrodes at 1 and 4 mg/kg. At 8 mg/kg increases obtained from ACC electrodes were significantly lower than those recorded from VAS. Onset of the change in electrochemical signal paralleled the onset of activity or stereotypy but the subsequent declines in signal and behavior were only loosely correlated. At the 4 mg/kg dose, the magnitude of signal increase from striatum was negatively correlated with indices of stereotypy and positively correlated with locomotor counts.