 |
||||
|
||||
|
||||
|
||||
The Journal of Neuroscience, April 5, 2006, 26(14):3805-3812; doi:10.1523/JNEUROSCI.4305-05.2006
Previous Article | Next Article
Behavioral/Systems/Cognitive
Amphetamine Exposure Enhances Habit Formation
Andrew Nelson andSimon Killcross School of Psychology, Cardiff University, Cardiff CF10 3AT, United Kingdom
Correspondence should be addressed to Dr. Simon Killcross, School of Psychology, Tower Building, Park Place, Cardiff University, Cardiff CF10 3AT, UK. Email: KillcrossAS{at}cardiff.ac.uk
Performance of instrumental actions in rats is initially sensitive to postconditioning changes in reward value, but after more extended training, behavior comes to be controlled by stimulus–response (S-R) habits that are no longer goal directed. To examine whether sensitization of dopaminergic systems leads to a more rapid transition from action–outcome processes to S-R habits, we examined performance of amphetamine-sensitized rats in an instrumental devaluation task. Animals were either sensitized (7 d, 2 mg/kg/d) before training (experiment 1) or sensitized between training and testing (experiment 2). Rats were trained to press a lever for a reward (three sessions) and were then given a test of goal sensitivity by devaluation of the instrumental outcome before testing in extinction. Control animals showed selective sensitivity to devaluation of the instrumental outcome. However, amphetamine sensitization administered before training caused the animals’ responding to persist despite the changed value of the reinforcer. This deficit resulted from an inability to use representations of the outcome to guide behavior, because a reacquisition test confirmed that all of the animals had acquired an aversion to the reinforcer. In experiment 2, post-training sensitization did not disrupt normal goal-directed behavior. These findings indicate that amphetamine sensitization leads to a rapid progression from goal-directed to habit-based responding but does not affect the performance of established goal-directed actions.
Key words: goal-directed action; habits; sensitization; amphetamine; striatum; dopamine
Received Oct. 10, 2005; revised March 1, 2006; accepted March 1, 2006.
Correspondence should be addressed to Dr. Simon Killcross, School of Psychology, Tower Building, Park Place, Cardiff University, Cardiff CF10 3AT, UK. Email: KillcrossAS{at}cardiff.ac.uk
Related articles in J. Neurosci.:
- Sensitization Facilitates Habit Formation: Implications for Addiction
- Sietse Jonkman
J. Neurosci. 2006 26: 7319-7320.[Full Text]
This article has been cited by other articles:
C. S. McPherson, T. Featherby, E. Krstew, and J. L. Andrew
Quantification of Phosphorylated cAMP-Response Element-Binding Protein Expression throughout the Brain of Amphetamine-Sensitized Rats: Activation of Hypothalamic Orexin A-Containing Neurons
J. Pharmacol. Exp. Ther., December 1, 2007; 323(3): 805 - 812.
[Abstract] [Full Text] [PDF]
J. R. Wickens, J. C. Horvitz, R. M. Costa, and S. Killcross
Dopaminergic Mechanisms in Actions and Habits
J. Neurosci., August 1, 2007; 27(31): 8181 - 8183.
[Abstract] [Full Text] [PDF]
M. R. Roesch, Y. Takahashi, N. Gugsa, G. B. Bissonette, and G. Schoenbaum
Previous Cocaine Exposure Makes Rats Hypersensitive to Both Delay and Reward Magnitude
J. Neurosci., January 3, 2007; 27(1): 245 - 250.
[Abstract] [Full Text] [PDF]
S. Jonkman
Sensitization Facilitates Habit Formation: Implications for Addiction
J. Neurosci., July 12, 2006; 26(28): 7319 - 7320.
[Full Text] [PDF]
|
|
|
|
 |
|