Effects of social reorganization on dopamine D2/D3 receptor availability and cocaine self-administration in male cynomolgus monkeys
| Autor: | H.D. Gage, Michael A. Nader, Paul W. Czoty, Robert W. Gould |
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| Rok vydání: | 2017 |
| Předmět: |
Male
0301 basic medicine Caudate nucleus Physiology Self Administration Hierarchy Social Pharmacology Choice Behavior Article 03 medical and health sciences 0302 clinical medicine Cocaine Dopamine Uptake Inhibitors Dopamine receptor D3 Dopamine receptor D2 Animals Environmental enrichment Dose-Response Relationship Drug Receptors Dopamine D2 Putamen Receptors Dopamine D3 Dominance hierarchy Macaca fascicularis 030104 developmental biology Social Dominance Dopamine receptor Caudate Nucleus Psychology Self-administration Reinforcement Psychology 030217 neurology & neurosurgery |
| Zdroj: | Psychopharmacology. 234:2673-2682 |
| ISSN: | 1432-2072 0033-3158 |
| DOI: | 10.1007/s00213-017-4658-x |
| Popis: | Studies have demonstrated that brain dopamine D2/D3 receptors (D2/D3R) and the reinforcing effects of cocaine can be influenced by a monkey’s position in the social dominance hierarchy. In this study, we manipulated the social ranks of monkeys by reorganizing social groups and assessed effects on D2/D3R availability and cocaine self-administration. Male cynomolgus monkeys (N = 12) had been trained to self-administer cocaine under a concurrent cocaine-food reinforcement schedule. Previously, PET measures of D2/D3R availability in the caudate nucleus and putamen had been obtained with [18F]fluoroclebopride during cocaine abstinence, while monkeys lived in stable social groups of four monkeys/pen. For this study, monkeys were reorganized into groups that consisted of (1) four previously dominant, (2) four previously subordinate, and (3) a mix of previously dominant and subordinate monkeys. After 3 months, D2/D3R availability was redetermined and cocaine self-administration was reexamined. D2/D3R availability significantly increased after reorganization in monkeys who were formerly subordinate, with the greatest increases observed in those that became dominant. No consistent changes in D2/D3R availability were observed in formerly dominant monkeys. Cocaine self-administration did not vary according to rank after reorganization of social groups. However, when compared to their previous cocaine self-administration data, the potency of cocaine as a reinforcer decreased in 9 of 11 monkeys. These results indicate that changing the social conditions can alter D2/D3R availability in subordinate monkeys in a manner suggestive of environmental enrichment. In most monkeys, social reorganization shifted the cocaine dose-response curve to the right, also consistent with environmental enrichment. |
| Databáze: | OpenAIRE |
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