D-amphetamine Facilitation of Morris Water Task Performance Is Blocked by Eticlopride and Correlated With Increased Dopamine Synthesis in the Prefrontal Cortex

Behav Brain Res. 2000 Sep;114(1-2):135-43. doi: 10.1016/s0166-4328(00)00225-4.

Abstract

The effect of posttraining D-amphetamine on Morris water task (MWT) performance was analyzed in this study by training rats using a single training trial per day procedure. In addition to acquisition latency, learning was assessed by a probe trial given 24 h after the last training trial. Rats given immediate post-trial D-amphetamine demonstrated improved performance over saline rats on both acquisition and the probe trial. An analysis of the mechanisms underlying facilitation revealed that eticlopride (a D2 antagonist) blocked D-amphetamine's facilitatory effects on the probe trial and dopamine synthesis was increased in the medial prefrontal cortex in the D-amphetamine group relative to controls. These results show that chronic administration of posttraining D-amphetamine facilitated MWT performance, and this facilitation may be mediated by the dopaminergic system and dopamine synthesis in the prefrontal cortex.

MeSH terms

  • Animals
  • Central Nervous System Stimulants / antagonists & inhibitors*
  • Central Nervous System Stimulants / pharmacology*
  • Dextroamphetamine / antagonists & inhibitors*
  • Dextroamphetamine / pharmacology*
  • Dihydroxyphenylalanine / metabolism
  • Dopamine / biosynthesis*
  • Dopamine / metabolism
  • Dopamine Antagonists / pharmacology*
  • Male
  • Maze Learning / drug effects*
  • Prefrontal Cortex / drug effects
  • Prefrontal Cortex / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Salicylamides / pharmacology*

Substances

  • Central Nervous System Stimulants
  • Dopamine Antagonists
  • Salicylamides
  • Dihydroxyphenylalanine
  • eticlopride
  • Dextroamphetamine
  • Dopamine