Evidence map›Paper›PMID 20526585›Full record

ArticlePsychopharmacology2010

Discriminative stimulus effects of serotonin agonists, neutral antagonists, and inverse agonists in pigeons: perspectives on intrinsic efficacy measurements in vivo.

Martilias Farrell, Sharon Rosenzweig-Lipson, Ellen Walker

Abstract readComparative Study
In one paragraph

Article in Psychopharmacology, 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Martilias FarrellDepartment of Pharmaceutical Sciences, School of Pharmacy, Temple University, 3307 North Broad Street, Philadelphia, PA 19140, USA.
Sharon Rosenzweig-Lipson
Ellen Walker

Funding

Behavioral Pharmacology of Serotonin Inverse AgonistsR01DA014673 · NIDA · TEMPLE UNIV OF THE COMMONWEALTH · PI WALKER, ELLEN ANN · 2002 to 2006
$1.4M
NIDA NIH HHS DA14673NIDA NIH HHS R01 DA014673
6 · The paper itself

Abstract

rationaleThe extended ternary complex theory of receptor function states a ligand can be classified as an inverse agonist, agonist, or neutral antagonist based on its ability to preferentially stabilize the inactive conformation, the active conformation, or to have no preference for conformational state, respectively.

objectivesWhile serotonin(2C) (5-HT(2C)) receptor ligands are classified accordingly in vitro, whether the phenomenon of inverse agonism manifests itself and/or is physiologically relevant in vivo is unknown.

methodsTherefore, we tested a range of proposed agonists, neutral antagonists, and inverse agonists with activity at 5-HT(2C) receptors in three groups of pigeons trained to discriminate saline from: 1.0 mg/kg MK212, an agonist; 0.1 mg/kg methysergide, a proposed neutral antagonist; or, 10 mg/kg mianserin, a proposed inverse agonist.

resultsBased on the patterns of substitution, the discriminative stimulus effects of MK212 appear to be mediated through agonist actions and the stimulus effects of methysergide and mianserin appear to be mediated through antagonist actions. Selective 5-HT(2B/2C) inverse agonist SB206,553 (1 mg/kg) blocked the MK212 discriminative stimulus cue and substituted (0.32-10 mg/kg) in both methysergide- and mianserin-trained pigeons, confirming a 5-HT(2C) receptor role in mediating these discriminative stimuli. Inverse agonists and neutral antagonists fully substituted for methysergide. In addition to SB206,553, methysergide (0.032-1.0 mg/kg) and 5-HT(1A) agonist 8-OH-DPAT (0.32-1.0 mg/kg) substituted completely for mianserin suggesting a complex discriminative stimulus profile for this proposed inverse agonist.

conclusionsThese data and the subsequent analyses suggest that the discriminative cues of MK212, methysergide, and mianserin are different and that the drug discrimination paradigm is a useful functional assay to examine intrinsic efficacy in vivo.

Indexed as

AnimalsColumbidaeDiscrimination LearningDose-Response Relationship, DrugDrug Inverse AgonismMaleMethysergideMianserinPyrazinesReceptor, Serotonin, 5-HT2CSerotonin 5-HT1 Receptor AgonistsSerotonin 5-HT2 Receptor AgonistsSerotonin 5-HT2 Receptor AntagonistsSerotonin AntagonistsSerotonin Receptor Agonists6-chloro-2-(1-piperazinyl)pyrazineMethysergideMianserinPyrazinesReceptor, Serotonin, 5-HT2CSerotonin 5-HT1 Receptor AgonistsSerotonin 5-HT2 Receptor AgonistsSerotonin 5-HT2 Receptor AntagonistsSerotonin AntagonistsSerotonin Receptor Agonists

Identifiers

PMID20526585
PMCPMC13242637

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.