Extended Habit Training Reduces Dopamine Mediation of Appetitive Response Expression

  • Choi W
  • 86


    Mendeley users who have this article in their library.
  • 75


    Citations of this article.


A wide range of behaviors is impaired after disruption of dopamine (DA) transmission, yet behaviors that are reflexive, automatic, or elicited by salient cues often remain intact. Responses triggered by strong external cues appear to be DA independent. Here, we examined the possibility that a single behavior may become DA independent as a result of extended training. Rats were trained to execute a head-entry response to a cue signaling food delivery. Vulnerability of the response to D1 or D2 receptor blockade was assessed on day 3, 7, or 17 of 28-trial-per-day training. During the early stages of training, the D1 receptor antagonist R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (SCH 23390) increased response latencies; however, the same behavior was unaffected by SCH 23390 in animals tested during the later stages of training. Other aspects of behavior such as locomotion and head-entry responses during the uncued intertrial interval remained vulnerable to SCH 23390 throughout the experiment. This D1-mediated response was unaffected by the D2 antagonist raclopride, even at a dose that strongly suppressed locomotion. The results provide strong evidence that a D1-dependent behavior becomes less dependent on DA with extended training. A number of fundamental neurobiological changes occur as behaviors become learned habits; at least for some responses, this change involves a shift from D1-mediated to D1-independent responding.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • W. Y. Choi

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free