Endogenous opioid-induced neuroplasticity of dopaminergic neurons in the ventral tegmental area influences natural and opiate reward
| Autor: | Steven R. Laviolette, Jonathan Fuller, Sandy Van, Michael N. Lehman, Lauren N. Beloate, Kyle K. Pitchers, Karla S. Frohmader, Caroline M. Coppens, Lique M. Coolen |
|---|---|
| Přispěvatelé: | Faculteit Medische Wetenschappen/UMCG |
| Rok vydání: | 2014 |
| Předmět: |
Male
Narcotic Antagonists NUCLEUS-ACCUMBENS SET-POINT Mesolimbic pathway Nucleus accumbens memory ACTIVATION Rats Sprague-Dawley Reward system Reward Dopamine Conditioning Psychological Copulation medicine Animals MESOLIMBIC SYSTEM Endogenous opioid SEXUAL-BEHAVIOR Neuronal Plasticity Morphine Naloxone General Neuroscience Dopaminergic Neurons Dopaminergic Ventral Tegmental Area mesolimbic CONDITIONED PLACE PREFERENCE MALE-RATS Association Learning Articles DELTA-FOSB Conditioned place preference Rats Ventral tegmental area medicine.anatomical_structure nervous system CHRONIC MORPHINE dopamine ESTROUS FEMALE Psychology Neuroscience psychological phenomena and processes medicine.drug |
| Zdroj: | The Journal of Neuroscience, 34(26), 8825-8836. Oxford University Press |
| ISSN: | 1529-2401 0270-6474 |
| Popis: | Natural reward and drugs of abuse converge on the mesolimbic pathway and activate common mechanism of neural plasticity in the nucleus accumbens. Chronic exposure to opiates induces plasticity in dopaminergic neurons of the ventral tegmental area (VTA), which regulates morphine reward tolerance. Here, we test the hypotheses that mating-induced release of endogenous opioids in the VTA causes morphological changes of VTA dopamine cells in male rats, which in-turn regulate the long-term expression of experience-induced reinforcement of sexual behavior. First, sexual experience decreased VTA dopamine soma size 1 and 7 days, but not 30 days after the last mating session. This effect was blocked with naloxone before each mating session; thus, VTA dopamine cell plasticity was dependent on action of endogenous opioids. In turn, VTA plasticity was associated with altered opiate reward, as sexually experienced males did not form conditioned place preference for 0.5 mg/kg morphine. Next, it was determined whether endogenous opioid action mediates sexual reward and memory in male rats treated with naloxone during mating experience, either systemically or intra-VTA. Naloxone did not prevent the initial experience-induced facilitation of sexual behavior over repeated mating sessions, or conditioned place preference for mating. However, naloxone treatment attenuated the longer-term expression of experience-induced facilitation of sexual behavior and neural activation in mesolimbic areas induced by mating-associated conditioned cues. Together, these data demonstrate that endogenous opioids during mating induce neural plasticity in VTA dopamine neurons that appear critical for morphine reward and long-term memory for natural reward behavior. |
| Databáze: | OpenAIRE |
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