Cerebral Cortex Advance Access first published online on July 15, 2009
This version published online on August 12, 2009
Cerebral Cortex, doi:10.1093/cercor/bhp151
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The Role of Dopamine in the Prelimbic Cortex and the Dorsomedial Striatum in Instrumental Conditioning
Abteilung Tierphysiologie, Biologisches Institut, Universität Stuttgart, D-70550 Stuttgart, Germany
Address correspondence to Wolfgang Hauber, Pfaffenwaldring 57, Biologisches Institut, Abteilung Tierphysiologie, 70550 Stuttgart, Germany. Email: Hauber{at}bio.uni-stuttgart.de.
The prelimbic (PL) region of the prefrontal cortex and the posterior subregion of the dorsomedial striatum (pDMS) are components of a corticostriatal circuit subserving instrumental learning. Here, we examined whether dopamine (DA) signals conveyed to the PL and pDMS are critical for instrumental learning. Rats with 6-hydroxydopamine or vehicle infusion into the PL and pDMS were trained to press 2 levers, either for food pellets or a sucrose solution. Thereafter, we tested whether the animals were sensitive 1) to a selective degradation of 1 of 2 outcomes using a specific satiety procedure and 2) to a selective degradation of 1 of 2 contingencies controlling instrumental behavior. Rats with PL DA depletion displayed a reduced rate of lever presses but appeared to be sensitive to outcome devaluation and contingency degradation. Thus, PL DA seems to modulate lever pressing but does not support instrumental conditioning. In contrast, rats with pDMS DA depletion had intact response rates and were sensitive to selective outcome devaluation; however, they showed a reduced sensitivity to contingency degradation. Therefore, pDMS DA signaling seems not to be involved in maintaining lever pressing but instead contributes to instrumental conditioning by supporting the detection of causal relationships between an action and its consequences.
Key Words: instrumental conditioning • posterior dorsomedial striatum • prelimbic cortex • rat
Updated to correct Figure 8.