Inter-individual differences in decision-making, flexible and goal-directed behaviors: novel insights within the prefronto-striatal networks

Brain Struct Funct. 2018 Mar;223(2):897-912. doi: 10.1007/s00429-017-1530-z. Epub 2017 Oct 12.

Abstract

Inflexible behavior is a hallmark of several decision-making-related disorders such as ADHD and addiction. As in humans, a subset of healthy rats makes poor decisions and prefers immediate larger rewards despite suffering large losses in a rat gambling task (RGT). They also display a combination of traits reminiscent of addiction, notably inflexible behavior and perseverative responses. The goal of the present work was twofold: (1) to elucidate if behavioral inflexibility of poor decision-makers could be related to a lower quality of goal-directed behavior (action-outcome associations); (2) to uncover the neural basis of inter-individual differences in goal-directed behavior. We specifically assessed inter-individual differences in decision-making in the RGT, flexibility in the RGT-reversed version and goal-directed behavior in a contingency degradation test, i.e., response adaptation when dissociating reward delivery from the animal's action. The contributions of the medial prefrontal cortex and the dorsal striatum to action-outcome associations were assessed using Zif268 immunodetection. Inflexible behavior was related to a lower sensitivity to contingency degradation in all poor decision-makers and only in a few good decision-makers. This poorer sensitivity was associated with a lower immunoreactivity in prelimbic and infralimbic cortices and a higher one in the dorsomedial and dorsolateral striatum. These findings suggest that an imbalanced prefronto-striatal activity could underlie inaccurate goal representation in changing environments and may promote maladaptive habit formation among poor decision-makers. These data strengthen our previous work identifying biomarkers of vulnerability to develop psychiatric disorders and demonstrate the relevance of inter-individual differences to model maladaptive behaviors.

Keywords: Decision-making; Goal-directed behavior; Inflexible behavior; Prefrontal cortex; Rat gambling task; Striatum.

MeSH terms

  • Animals
  • Conditioning, Operant / physiology
  • Corpus Striatum / physiology*
  • Decision Making / physiology*
  • Early Growth Response Protein 1 / metabolism
  • Gambling / psychology
  • Goals*
  • Individuality*
  • Male
  • Neural Pathways / physiology
  • Prefrontal Cortex / physiology*
  • Rats
  • Rats, Wistar
  • Reward*
  • Statistics, Nonparametric

Substances

  • Early Growth Response Protein 1
  • Egr1 protein, rat