Individual differences in the propensity to approach signals vs goals promote different adaptations in the dopamine system of rats (original) (raw)

Abstract

Rationale

The way an individual responds to cues associated with rewards may be a key determinant of vulnerability to compulsive behavioral disorders.

Objectives

We studied individual differences in Pavlovian conditioned approach behavior and examined the expression of neurobiological markers associated with the dopaminergic system, the same neural system implicated in incentive motivational processes.

Methods

Pavlovian autoshaping procedures consisted of the brief presentation of an illuminated retractable lever (conditioned stimulus) followed by the response-independent delivery of a food pellet (unconditioned stimulus), which lead to a Pavlovian conditioned response. In situ hybridization was performed on brains obtained either following the first or last (fifth) day of training.

Results

Two phenotypes emerged. Sign-trackers (ST) exhibited behavior that seemed to be largely controlled by the cue that signaled impending reward delivery; whereas goal-trackers (GT) preferentially approached the location where the reward was delivered. Following a single training session, ST showed greater expression of dopamine D1 receptor mRNA relative to GT. After 5 days of training, GT exhibited greater expression levels of tyrosine hydroxylase, dopamine transporter, and dopamine D2 receptor mRNA relative to ST.

Conclusions

These findings suggest that the development of approach behavior towards signals vs goal leads to distinct adaptations in the dopamine system. The sign-tracker vs goal-tracker phenotype may prove to be a valuable animal model to investigate individual differences in the way incentive salience is attributed to environmental stimuli, which may contribute to the development of addiction and other compulsive behavioral disorders.

Access this article

Log in via an institution

Subscribe and save

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

Download references

Acknowledgments

The authors would like to acknowledge the technical assistance of Tracy Simmons, James Stewart, Sharon Burke, and Jennifer Fitzpatrick. We would also like to thank James Beals for assistance with preparing the figures and Brady West (CSCAR, University of Michigan) for providing statistical consultation.

Author information

Authors and Affiliations

  1. Molecular and Behavioral Neuroscience Institute, University of Michigan, 205 Zina Pitcher Place, Ann Arbor, MI, 48109-0720, USA
    Shelly B. Flagel, Stanley J. Watson & Huda Akil
  2. Department of Psychology, The University of Michigan, Ann Arbor, MI, USA
    Terry E. Robinson

Authors

  1. Shelly B. Flagel
    You can also search for this author inPubMed Google Scholar
  2. Stanley J. Watson
    You can also search for this author inPubMed Google Scholar
  3. Terry E. Robinson
    You can also search for this author inPubMed Google Scholar
  4. Huda Akil
    You can also search for this author inPubMed Google Scholar

Corresponding author

Correspondence toShelly B. Flagel.

Additional information

This work was supported by grants from the National Institute of Drug Abuse to H.A. (R01 DA013386) and T.E.R. (R37 DA04294) and from the Office of Naval Research to H.A. and S.J.W. (N00014-02-1-0879).

Rights and permissions

About this article

Cite this article

Flagel, S.B., Watson, S.J., Robinson, T.E. et al. Individual differences in the propensity to approach signals vs goals promote different adaptations in the dopamine system of rats.Psychopharmacology 191, 599–607 (2007). https://doi.org/10.1007/s00213-006-0535-8

Download citation

Keywords