Related Experiment Video
Updated: Jul 28, 2026

Quantifying Agonist Activity at G Protein-coupled Receptors
Published on: December 26, 2011
Antidepressant-like activity of CGP 36742 and CGP 51176, selective GABAB receptor antagonists, in rodents
G Nowak1, A Partyka, A Pałucha
1Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland.
Background And Purpose:
A crucial role for the GABAB receptor in depression was proposed several years ago, but there are limited data to support this proposition. Therefore we decided to investigate the antidepressant-like activity of the selective GABAB receptor antagonists CGP 36742 and CGP 51176, and a selective agonist CGP 44532 in models of depression in rats and mice.
Experimental Approach:
Effects of CGP 36742 and CGP 51176 as well as the agonist CGP 44532 were assessed in the forced swim test in mice. Both antagonists were also investigated in an olfactory bulbectomy (OB) model of depression in rats, while CGP 51176 was also investigated in the chronic mild stress (CMS) rat model of depression. The density of GABAB receptors in the mouse hippocampus after chronic administration of CGP 51176 was also investigated.
Key Results:
The GABAB receptor antagonists CGP 36742 and CGP 51176 exhibited antidepressant-like activity in the forced swim test in mice. The GABAB receptor agonist CGP 44532 was not effective in this test, however, it counteracted the antidepressant-like effects of CGP 51176. The antagonists CGP 36742 and CGP 51176 were effective in an OB model of depression in rats. CGP 51176 was also effective in the CMS rat model of depression. Administration of CGP 51176 increased the density of GABAB receptors in the mouse hippocampus.
Conclusions And Implications:
These data suggest that selective GABAB receptor antagonists may be useful in treatment of depression, and support an important role for GABA-ergic transmission in this disorder.
Related Concept Videos
G-protein Coupled Receptors
G Protein-coupled Receptors
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
Adrenergic Agonists: Indirect-Acting Agents
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...
Drugs Affecting Neurotransmitter Release or Uptake
Antidepressant Drugs: MAOIs and Other Agents
Drugs Affecting GI Tract Motility: Serotonin Receptor Agonists

