Effects of prefrontal cortical inactivation on neural activity in the ventral tegmental area
| Autor: | Yong Sang Jo, Sheri J. Y. Mizumori, Jane Lee |
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| Rok vydání: | 2013 |
| Předmět: |
Agonist
Male Microinjections medicine.drug_class Dopamine Action Potentials Prefrontal Cortex Spatial memory Statistics Nonparametric Article chemistry.chemical_compound Reward Memory medicine Animals Rats Long-Evans Prefrontal cortex Maze Learning Sensory cue Neurons Afferent Pathways Analysis of Variance GABAA receptor Muscimol General Neuroscience musculoskeletal neural and ocular physiology Ventral Tegmental Area Rats Ventral tegmental area medicine.anatomical_structure chemistry nervous system Space Perception Psychology Neuroscience psychological phenomena and processes medicine.drug |
| Zdroj: | The Journal of neuroscience : the official journal of the Society for Neuroscience. 33(19) |
| ISSN: | 1529-2401 |
| Popis: | Dopamine (DA) cells have been suggested to signal discrepancies between expected and actual rewards in reinforcement learning. DA cells in the ventral tegmental area (VTA) receive direct projections from the medial prefrontal cortex (mPFC), a structure known to be one of the brain areas that represents expected future rewards. To investigate whether the mPFC contributes to generating reward prediction error signals of DA cells, we recorded VTA cells from rats foraging for different amounts of reward in a spatial working memory task. Our results showed that DA cells initially responded after the acquisition of rewards, but over training, they exhibited phasic responses when rats detected sensory cues originating from the rewards before obtaining them. We also observed two separate groups of non-DA cells activated in expectation of upcoming rewards or during reward consumption. Bilateral injections of muscimol, a GABAAagonist, into the mPFC significantly decreased the non-DA activity that encoded reward expectation. By contrast, the same manipulation of the mPFC elevated DA responses to reward-predicting cues. However, neither DA nor non-DA responses elicited after reward acquisition were affected by mPFC inactivation. These results suggest that the mPFC provides information about expected rewards to the VTA, and its functional loss elevates DA responses to reward-predicting cues by altering expectations about forthcoming rewards. |
| Databáze: | OpenAIRE |
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