Enhanced Acquisition of Cocaine Self-Administration in Rats Developmentally Exposed to Lead
| Autor: | Gerald R. Bratton, Angelica Rocha, Jack R. Nation, Rodrigo Valles, Aaron L. Cardon |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Male
Reinforcement Schedule Self Administration Rats Sprague-Dawley Cocaine Pregnancy Lactation medicine Animals Weaning Tissue Distribution Anesthetics Local Lead (electronics) Postnatal day Pharmacology Behavior Animal Dose-Response Relationship Drug medicine.disease Rats Psychiatry and Mental health medicine.anatomical_structure Animals Newborn Lead Prenatal Exposure Delayed Effects Anesthesia Lead exposure Conditioning Operant Gestation Female Self-administration Psychology |
| Zdroj: | Neuropsychopharmacology. 30:2058-2064 |
| ISSN: | 1740-634X 0893-133X |
| Popis: | The rate of acquisition of drug self-administration may serve as a predictor of later drug-taking behavior, possibly influencing the vulnerability to use drugs. The present study examined the effects of perinatal (gestation/lactation) lead exposure on adult rates of acquisition of intravenous cocaine self-administration using an automated procedure that included both Pavlovian and operant components. For Experiment 1, female rats were gavaged daily with 0 or 16 mg lead for 30 days prior to breeding with nonexposed males. Metal administration continued through pregnancy and lactation and was discontinued at weaning (postnatal day (PND) 21). Animals born to control or lead-exposed dams subsequently were tested daily as adults in a preparation where sessions included an initial 3-h autoshaping period followed by a 3-h self-administration period where 0.20 mg/kg cocaine was delivered contingently. During autoshaping, intravenous cocaine infusions were paired with the extension and retraction of a lever, while infusions occurred during self-administration only when a lever press was executed (FR-1). The criterion for acquisition was a 2-day period during which a mean of 50 infusions/session occurred during self-administration. Animals were given 35 days to reach criterion. In Experiment 1, accelerated rates of acquisition of cocaine self-administration were evident for lead-exposed animals relative to controls. Overall, the number of self-administered cocaine infusions per session was significantly higher for lead-exposed rats as compared to control rats. Experiment 2 replicated Experiment 1 except that a higher dose of cocaine (0.80 mg/kg) was employed as the reinforcer, and 30 infusions/session was the set criterion. At the higher cocaine dose (Experiment 2), acquisition rates for control and lead-exposed animals were not markedly different, and significantly different infusion rates were not observed. |
| Databáze: | OpenAIRE |
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