The hypothesis that dopamine (DA) receptor agonists and antagonists affect "hedonia" associated with natural rewards was tested, using a psychophysical procedure previously shown to be sensitive to both the sweetness of food and the motivational state of rats. Rats were first trained to discriminate
Food- and drug-reinforced responding: Effects of DITA andd-amphetamine
โ Scribed by David A. Downs; James H. Woods
- Publisher
- Springer
- Year
- 1975
- Tongue
- English
- Weight
- 544 KB
- Volume
- 43
- Category
- Article
- ISSN
- 0033-3158
No coin nor oath required. For personal study only.
โฆ Synopsis
Intravenous pretreatment with DITA (0.1 - 1.0 mg/kg) decreased the rate of food-reinforcement lever pressing in rhesus monkeys. Response rate decreases were dose-dependent but showed the development of tolerance. Self-administration of DITA was initiated and maintained in each of three monkeys when 30 lever presses were required to produce each injection. Maximal response rate during periods of drug availability was maintained by 0.03 mg/kh/injection while higher and lower doses (0.01 and 0.10 mg/kg/injection) maintained lower response rates. Response rate in periods of food availability immediately preceding drug periods was relatively constant across session; response rate in periods of food availability immediately following drug periods, however, decreased with increasing amounts of drug self-administered. Replication of initial self-administration doses produced results comparable to original determinations in contrast to the tolerance observed with DITA effects upon food-reinforced responding. DITA was about 3 times less potent than d-amphetamine in maintaining response rates in drug periods and in decreasing the rate of subsequent food-reinforced responding.
๐ SIMILAR VOLUMES
Rats learned not to respond on non-reinforced trials in a discrete trial situation in which trial responses were reinforced only if preceded by three or more non-response trials. Drug effects were measured: 1) when the same external stimuli were present on all trims and trial responding was therefor