Related Experiment Video
Updated: Jun 11, 2025
Assessing Changes in Volatile General Anesthetic Sensitivity of Mice after Local or Systemic Pharmacological Intervention
Published on: October 16, 2013
Evaluation of the sedative-motor effects of novel GABAkine imidazodiazepines using quantitative observation
Dishary Sharmin1, Daniela Rüedi-Bettschen2, Laís F Berro2
1Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
Background:
Benzodiazepines bind to γ-aminobutyric acid type A (GABAA) receptor subtypes identified by different α subunits (i.e., α1GABAA, α2GABAA, α3GABAA, and α5GABAA). Sedative-motor effects of benzodiazepines are thought to involve α1GABAA and α3GABAA subtypes.
Aims:
We evaluated observable measures of sedative-motor effects and species-typical behaviors in monkeys following acute administration of novel GABAkines (positive allosteric modulators of GABAA receptors), with varying degrees of selective efficacy at different GABAA receptor subtypes. We predicted that the induction of sedative-motor effects would depend on the degree of α1GABAA and α3GABAA efficacy.
Methods:
Adult female rhesus monkeys (N = 4) were implanted with chronic indwelling i.v. catheters. Quantitative behavioral observation was conducted by trained observers following administration of multiple doses of the conventional benzodiazepine alprazolam and the GABAkines MP-III-80 (preferential efficacy at α2/α3/α5GABAA subtypes), KRM-II-81, MP-III-24 (both with preferential efficacy for α2/α3GABAA subtypes), and MP-III-22 (preferential potency and efficacy for α5GABAA subtypes).
Results:
As with alprazolam, all GABAkines induced significant levels of mild sedation ("rest/sleep posture"). Deep sedation was observed with alprazolam, MP-III-80, and MP-III-22; motoric effects (observable ataxia) were obtained with alprazolam, KRM-II-81, and MP-III-22 only. Surprisingly, the order of potency for rest/sleep posture was significantly associated only with potency at α5GABAA subtypes.
Conclusions:
GABAkines with preferential efficacy at α2/α3GABAA and/or α5GABAA subtypes engendered sedative-motor effects in monkeys, although only compounds with α5GABAA activity engendered deep sedation. Moreover, the significant relationship between potency obtained with in vitro electrophysiology data and the rest/sleep posture measure suggests a role for the α5GABAA subtype in this milder form of sedation.
More Related Videos
07:16Methods for the Discovery of Novel Compounds Modulating a Gamma-Aminobutyric Acid Receptor Type A Neurotransmission
Published on: August 16, 2018
07:54Testing Animal Anxiety in Rats: Effects of Open Arm Ledges and Closed Arm Wall Transparency in Elevated Plus Maze Test
Published on: June 29, 2018
Related Concept Videos
01:17Sedatives and Hypnotics Drugs: Miscellaneous Agents
Melatonin congeners like ramelteon (Rozerem) and tasimelteon (Hetlioz) selectively bind to melatonin receptors (MT1 and MT2) and thus mimic the actions of melatonin, a hormone that regulates sleep-wake cycles. Tasimelteon is primarily used for non-24-hour sleep-wake disorder, common in blind patients. They are also used to treat conditions like insomnia...
01:23Sedatives and Hypnotics: Overview
Sedative-hypnotics are categorized into barbiturates, benzodiazepines (BZDs), and non-benzodiazepines or Z-drugs. These drugs work by suppressing central nervous system activity, and this suppression is dose-dependent. Older sedative medications, like barbiturates, follow a linear curve in...
01:20Antiepileptic Drugs: Potassium Channel Activators
Ezogabine has gained approval as an adjunctive treatment...
01:19Sedatives and Hypnotics Drugs: Benzodiazepines
Benzodiazepines work by enhancing the effects of the inhibitory neurotransmitter GABA. They bind to the GABAA receptor, increasing its affinity for GABA, which opens chloride...
01:20Sedatives and Hypnotics Drugs: Barbiturates
01:29Anxiolytic Drugs: Benzodiazepines and Buspirone