Parallel Maturation of Goal-Directed Behavior and Dopaminergic Systems during Adolescence
Journal of Neuroscience. 2012-11-14; 32(46): 16223-16232
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1. J Neurosci. 2012 Nov 14;32(46):16223-32. doi: 10.1523/JNEUROSCI.3080-12.2012.
Parallel maturation of goal-directed behavior and dopaminergic systems during
Naneix F(1), Marchand AR, Di Scala G, Pape JR, Coutureau E.
(1)Centre National de la Recherche Scientifique, Institut de Neurosciences
Cognitives et Intégratives d’Aquitaine, UMR 5287, F-33400 Talence, France.
Adolescence is a crucial developmental period characterized by specific behaviors
reflecting the immaturity of decision-making abilities. However, the maturation
of precise cognitive processes and their neurobiological correlates at this
period remain poorly understood. Here, we investigate whether a differential
developmental time course of dopamine (DA) pathways during late adolescence could
explain the emergence of particular executive and motivational components of
goal-directed behavior. First, using a contingency degradation protocol, we
demonstrate that adolescent rats display a specific deficit when the causal
relationship between their actions and their consequences is changed. When the
rats become adults, this deficit disappears. In contrast, actions of adolescents
remain sensitive to outcome devaluation or to the influence of a
pavlovian-conditioned stimulus. This aspect of cognitive maturation parallels a
delayed development of the DA system, especially the mesocortical pathway
involved in action adaptation to rule changes. Unlike in striatal and nucleus
accumbens regions, DA fibers and DA tissue content continue to increase in the
medial prefrontal cortex from juvenile to adult age. Moreover, a sustained
overexpression of DA receptors is observed in the prefrontal region until the end
of adolescence. These findings highlight the relationship between the emergence
of specific cognitive processes, in particular the adaptation to changes in
action consequences, and the delayed maturation of the mesocortical DA pathway.
Similar developmental processes in humans could contribute to the adolescent
vulnerability to the emergence of several psychiatric disorders characterized by
PMID: 23152606 [Indexed for MEDLINE]