ArticlesThe Effects of Microinjection of d-Amphetamine Into The N. Accumbens During the Late Maintenance Phase of an Ethanol Consumption Bout
Section snippets
Subjects
Male Long–Evans rats, weighing between 200–225 g at the start of the experiment, were housed individually in standard hanging wire cages in an AAALAC-approved vivarium with ad lib food and water always available. The vivarium was maintained on a 12 L:12 D cycle, with the lights on at 0600 h. All experimental sessions were run during the light portion of the cycle. The rats were maintained in accordance with the NIH guidelines at all phases of the experiment.
Apparatus
Self-administration sessions were
Results
Thirty rats were used in this study. Nine animals developed an infection at various times following the surgery and had to be sacrificed prior to completing the experiment, two rats failed to regain baseline ethanol self-administration after surgery and were discontinued, six rats damaged their head stage connector mounts during the experiment and had to be discontinued with only partial data collected, and three rats were found upon histological examination to have incorrect bilateral cannula
Discussion
The primary objective of this study was to determine if amphetamine microinjected into the n. accumbens during the later phases of an ethanol self-administration bout would produce an effect similar to that observed when the microinjection occurred prior to bout onset. Based on our regulatory model of ethanol bout control (10), it was hypothesized that a microinjection during the late maintenance phase would delay termination of responding and increase intake; an effect similar to that observed
Acknowledgements
This research was supported by grants AA07404 and AA00142 from the National Institute on Alcohol Abuse and Alcoholism to HHS. Special thanks to Mr. H. Seibold of EMDEC, Bellevue, WA, for his assistance in the development of the microinjection equipment.
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Opioids in the nucleus accumbens stimulate ethanol intake
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