Ventral striatum lesions enhance stimulus and response encoding in dorsal striatum

Biol Psychiatry. 2014 Jan 15;75(2):132-9. doi: 10.1016/j.biopsych.2013.05.023. Epub 2013 Jun 20.

Abstract

Background: The development of addiction is thought to reflect a transition from goal-directed to stimulus-response driven behavior, functions attributed to ventral (VS) and dorsal striatum (DS), respectively. In line with this theory, neuroadaptations that occur during prolonged drug use progress from VS to DS. Here we ask if VS dysfunction alone, independent of drug use, can affect neural selectivity in DS.

Methods: To address this issue, we recorded from single neurons in DS while rats performed an odor-guided choice task for differently valued rewards in rats with and without unilateral VS lesions. In a separate group of animals, we used bilateral VS lesions to determine if VS was critical for performance on this task.

Results: We describe data showing that unilateral lesions of VS enhance neural representations in DS during performance of a task that is dependent on VS. Furthermore, we show that VS is critical for reward-guided decision-making initially, but that rats regain function after several days.

Conclusions: These results suggest that loss of VS function, independent of chronic drug use, can trigger stronger encoding in DS in a reward-guided decision-making task and that the transition from VS to DS governed behavior observed in addiction might be due, in part, to initial loss of VS function.

Keywords: Nucleus accumbens; rat; single unit; stimulus-response; striatum; value.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Action Potentials / physiology
  • Animals
  • Basal Ganglia / pathology*
  • Basal Ganglia / physiopathology*
  • Choice Behavior / physiology
  • Conditioning, Operant / physiology
  • Corpus Striatum / physiology*
  • Decision Making / physiology*
  • Male
  • Neurons / physiology
  • Rats
  • Recovery of Function / physiology
  • Reward