| Title |
Psychomotor stimulant effects of methylxanthines in squirrel monkeys: relation to adenosine antagonism
|
|---|---|
| Published in |
Psychopharmacology, May 1988
|
| DOI | 10.1007/bf00212759 |
| Pubmed ID | |
| Authors |
R. D. Spealman |
| Abstract |
The behavioral effects of six methylxanthines were studied in squirrel monkeys responding under a fixed-interval (FI) schedule of stimulus-shock termination. Dose-response curves were determined for each drug by administering cumulative doses IV during timeout periods that preceded sequential components of the FI schedule. Low to intermediate doses of caffeine, theophylline, 8-phenyltheophylline (8-PT), 8-cyclopentyltheophylline (CPT), and 3-isobutyl-1-methylxanthine (IBMX) produced dose-related increases in response rate, whereas higher doses increased response rate less or decreased it. Enprofylline did not increase response rate at any dose. Pretreatment with a high dose of the adenosine agonist 5'-N-ethylcarboxamide adenosine (NECA) suppressed responding throughout the experimental session. Caffeine, theophylline, 8-PT, CPT, and IBMX, but not enprofylline, antagonized the suppressant effects of NECA in a dose-related manner. The potencies of the methylxanthines for increasing response rate under the FI schedule were positively correlated with their potencies for antagonizing the suppressant effects of NECA, suggesting that the psychomotor stimulant effects of methylxanthines are linked to their antagonistic actions at adenosine recognition sites. CPT, which in vitro has much higher affinity (greater than 10(3)-fold) than caffeine for adenosine A1, but not for A2, recognition sites, was only 3-6 times more potent than caffeine in increasing response rate or in antagonizing the effects of NECA. The psychomotor stimulant effects of methylxanthines therefore appear to be more closely associated with antagonism at adenosine A2 than adenosine A1 recognition sites. |
Mendeley readers
The data shown below were compiled from readership statistics for 7 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 7 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Ph. D. Student | 1 | 14% |
| Student > Bachelor | 1 | 14% |
| Researcher | 1 | 14% |
| Student > Master | 1 | 14% |
| Unknown | 3 | 43% |
| Readers by discipline | Count | As % |
|---|---|---|
| Psychology | 1 | 14% |
| Sports and Recreations | 1 | 14% |
| Neuroscience | 1 | 14% |
| Chemistry | 1 | 14% |
| Unknown | 3 | 43% |
Attention Score in Context
This research output has an Altmetric Attention Score of 3. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 20 April 2023.
All research outputs
#7,756,853
of 23,578,918 outputs
Outputs from Psychopharmacology
#2,166
of 5,418 outputs
Outputs of similar age
#3,840
of 13,550 outputs
Outputs of similar age from Psychopharmacology
#4
of 10 outputs
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