Inter-individual differences in decision-making, flexible and goal-directed behaviors: novel insights within the prefronto-striatal networks.
Brain Struct Funct. 2017-10-12; 223(2): 897-912
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Fitoussi A(1)(2), Renault P(1)(2), Le Moine C(1)(2), Coutureau E(1)(2), Cador M(1)(2), Dellu-Hagedorn F(3)(4)(5).
(1)University of Bordeaux, INCIA, UMR 5287, 33000, Bordeaux, France.
(2)CNRS, INCIA, UMR 5287, 33000, Bordeaux, France.
(3)University of Bordeaux, INCIA, UMR 5287, 33000, Bordeaux, France..
(4)CNRS, INCIA, UMR 5287, 33000, Bordeaux, France. .
(5)University of Bordeaux, INCIA, CNRS, UMR 5287, 146 rue Léo Saignat, BP 31,
33076, Bordeaux Cedex, France.
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.