Adolescent changes in dopamine D1 receptor expression in orbitofrontal cortex and piriform cortex accompany an associative learning deficit
| Autor: | Chloe R. Lawyer, Brittni M. Peterson, Kurt R. Illig, Anna K. Garske |
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| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Male
Aging lcsh:Medicine Social and Behavioral Sciences Pediatrics Behavioral Ecology Behavioral Neuroscience Learning and Memory Piriform cortex Psychology lcsh:Science Cerebral Cortex Drug Dependence Multidisciplinary Animal Behavior Neuromodulation Dopaminergic Neurochemistry Animal Models Neurotransmitters Immunohistochemistry Sensory Systems Behavioral Pharmacology Dopamine receptor Medicine psychological phenomena and processes Research Article medicine.drug Drugs and Devices education Biology Real-Time Polymerase Chain Reaction Model Organisms Dopamine receptor D1 Eticlopride Adolescent Medicine Dopamine Recreational Drug Use medicine Animals Rats Long-Evans RNA Messenger Evolutionary Biology Olfactory System Behavior Receptors Dopamine D1 lcsh:R Association Learning Rats Associative learning Gene Expression Regulation Odorants Rat Orbitofrontal cortex lcsh:Q Attention (Behavior) Neuroscience |
| Zdroj: | PLoS ONE, Vol 8, Iss 2, p e56191 (2013) PLoS ONE |
| ISSN: | 1932-6203 |
| Popis: | The orbitofrontal cortex (OFC) and piriform cortex are involved in encoding the predictive value of olfactory stimuli in rats, and neural responses to olfactory stimuli in these areas change as associations are learned. This experience-dependent plasticity mirrors task-related changes previously observed in mesocortical dopamine neurons, which have been implicated in learning the predictive value of cues. Although forms of associative learning can be found at all ages, cortical dopamine projections do not mature until after postnatal day 35 in the rat. We hypothesized that these changes in dopamine circuitry during the juvenile and adolescent periods would result in age-dependent differences in learning the predictive value of environmental cues. Using an odor-guided associative learning task, we found that adolescent rats learn the association between an odor and a palatable reward significantly more slowly than either juvenile or adult rats. Further, adolescent rats displayed greater distractibility during the task than either juvenile or adult rats. Using real-time quantitative PCR and immunohistochemical methods, we observed that the behavioral deficit in adolescence coincides with a significant increase in D1 dopamine receptor expression compared to juvenile rats in both the OFC and piriform cortex. Further, we found that both the slower learning and increased distractibility exhibited in adolescence could be alleviated by experience with the association task as a juvenile, or by an acute administration of a low dose of either the dopamine D1 receptor agonist SKF-38393 or the D2 receptor antagonist eticlopride. These results suggest that dopaminergic modulation of cortical function may be important for learning the predictive value of environmental stimuli, and that developmental changes in cortical dopaminergic circuitry may underlie age-related differences in associative learning. |
| Databáze: | OpenAIRE |
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