In vivo evidence that genetic background controls impulse-dependent dopamine release induced by amphetamine in the nucleus accumbens

J Neurochem. 2004 Apr;89(2):494-502. doi: 10.1111/j.1471-4159.2004.02342.x.

Abstract

Amphetamine is known to increase dopamine (DA) release by acting directly on dopamine transporters (DAT), primarily through a mechanism that is independent of impulse flow. We present evidence to show that impulse-dependent increase in DA outflow in the nucleus accumbens (NAc) is produced by amphetamine depending on genetic background. Systemic amphetamine produced higher accumbal DA release in the widely exploited C57BL/6J background than in the DBA/2J. By contrast, intra-accumbens perfusion using increasing doses of amphetamine dramatically increased DA outflow in the DBA/2J background, whereas very low DA outflow was evident in C57BL/6J mice. The fast sodium channel blocker tetrodotoxin infused through the microdialysis probe abolished accumbal DA release induced by systemic amphetamine only in the C57BL/6J background. Finally, medial prefrontal excitotoxic lesion abolished amphetamine-induced mesoaccumbens DA release in C57BL/6J mice, without significantly affecting it in the DBA/2J background. These results represent the first functional evidence in an in vivo study that amphetamine can increase DA release in the NAc mainly through an impulse-dependent mechanism regulated by prefronto-cortical glutamatergic transmission. Moreover, they point to a genetic control of impulse-dependent DA release in the accumbens, providing an exploitable tool to investigate aetiological factors involved in psychopathology and drug addiction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amphetamine / pharmacology*
  • Animals
  • Dopamine / metabolism*
  • Dopamine Agents / pharmacology
  • Dose-Response Relationship, Drug
  • Drug Administration Routes
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred DBA
  • Microdialysis
  • Neurotoxins / pharmacology
  • Nucleus Accumbens / drug effects*
  • Nucleus Accumbens / metabolism*
  • Piperazines / pharmacology
  • Prefrontal Cortex / drug effects
  • Prefrontal Cortex / physiology
  • Sodium Channel Blockers / pharmacology
  • Species Specificity
  • Synaptic Transmission / physiology*

Substances

  • Dopamine Agents
  • Neurotoxins
  • Piperazines
  • Sodium Channel Blockers
  • vanoxerine
  • Amphetamine
  • Dopamine