Novel-object place conditioning: behavioral and dopaminergic processes in expression of novelty reward

Behav Brain Res. 2002 Feb 1;129(1-2):41-50. doi: 10.1016/s0166-4328(01)00326-6.

Abstract

In a choice situation, rats given repeated access to novel objects in one of two distinct environments display an increase in preference for the novelty-paired environment. The experiments in this present report extend the generality of this effect to new procedures. Further, this shift in preference depends on object novelty; no systematic shift in preference was observed if the environment was paired with a familiar object. Experiments in the present report also provided evidence against non-associative accounts that rely on mechanisms that leave the paired environment more novel than the unpaired environment (e.g. object interaction interfering with environmental familiarization). Consistent with a conditioning account is the loss of place conditioning when access time with the novel objects was shortened from 10 min to 5 or 2.5 min. Interestingly, although a decrease in time with objects prevented place conditioning, these groups showed a novelty-conditioned increase in activity. Finally, treatment with the dopamine D(1) antagonist SCH-23390 (0.03 mg/kg) or the dopamine D(2)/D(3) antagonist eticlopride (0.1 mg/kg) before the post-conditioning preference test blocked expression of the novel-object place conditioning. Taken together, these experiments establish that the increased preference produced by object-environment pairings reflects a conditioned association between environmental cues and the appetitive effects of receiving access to novel stimuli.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Behavior, Animal / drug effects
  • Behavior, Animal / physiology*
  • Benzazepines / pharmacology
  • Conditioning, Operant / drug effects
  • Conditioning, Operant / physiology*
  • Cues
  • Dopamine / physiology*
  • Dopamine Antagonists / pharmacology
  • Environment*
  • Generalization, Psychological
  • Male
  • Motor Activity / drug effects
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Dopamine D1 / drug effects
  • Receptors, Dopamine D2 / drug effects
  • Receptors, Dopamine D3
  • Reward*
  • Salicylamides / pharmacology

Substances

  • Benzazepines
  • Dopamine Antagonists
  • Drd3 protein, rat
  • Receptors, Dopamine D1
  • Receptors, Dopamine D2
  • Receptors, Dopamine D3
  • Salicylamides
  • eticlopride
  • Dopamine