Roles of D1-like dopamine receptors in the nucleus accumbens and dorsolateral striatum in conditioned avoidance responses
Aversively motivated learning is more poorly understood than appetitively motivated learning in many aspects, including the role of dopamine receptors in different regions of the striatum.
The present study investigated the roles of the D1-like DA receptors in the nucleus accumbens (NAc) and dorsolateral striatum (DLS) on learning and performance of conditioned avoidance responses (CARs).
Adult male Wistar rats received intraperitoneal (i.p.), intra-NAc, or intra-DLS injections of the D1 dopamine receptor agonist SKF 81297 or the D1 receptor antagonist SCH 23390 20 min before or immediately after a training session in the CAR task two-way active avoidance, carried out 24 h before a test session.
Pre-training administration of SCH 23390, but not SKF 81297, caused a significant decrease in the number of CARs in the test, but not in the training session, when injected into the DLS, or in either session when injected into the NAc. It also caused a significant increase in the number of escape failures in the training session when injected into the NAc. Systemic administration caused a combination of these effects. Post-training administrations of these drugs caused no significant effect.
The results suggest that the D1-like receptors in the NAc and DLS play important, though different, roles in learning and performance of CAR.
KeywordsDorsolateral striatum Nucleus accumbens D1 dopamine receptor Two-way active avoidance Conditioned avoidance learning Memory Decision-making
- Da Cunha C, Wietzikoski EC, Dombrowski P, Santos LM, Bortolanza M, Boschen SL, Miyoshi E (2009) Learning processing in the basal ganglia: a mosaic of broken mirrors. Behav Brain Res 199:156–169Google Scholar
- Floresco SB, Phillips AG (1999) Dopamine and hippocampal input to the nucleus accumbens play an essential role in the search for food in an unpredictable environment. Psychobiology 27:277–286Google Scholar
- Gal G, Schiller D, Weiner I (2005) Latent inhibition is disrupted by nucleus accumbens shell lesion but is abnormally persistent following entire nucleus accumbens lesion: the neural site controlling the expression and disruption of the stimulus preexposure effect. Behav Brain Res 162:246–255PubMedCrossRefGoogle Scholar
- Hernandez-Lopez S, Bargas J, Surmeier DJ, Reyes A, Galarraga E (1987) D1 receptor activation enhances evoked discharge in neostriatal medium spiny neurons by modulating an l-type Ca2+ conductance. J Neurosci Methods 17:3334–3342Google Scholar
- Paxinos G, Watson C (2005) The rat brain in stereotaxic coordinates. Academic Press, San Diego, EUAGoogle Scholar