Novel Molecule Exhibiting Selective Affinity for GABAA Receptor Subtypes.

ABSTRACT: Aminoquinoline derivatives were evaluated against a panel of receptors/channels/transporters in radioligand binding experiments. One of these derivatives (DCUK-OEt) displayed micromolar affinity for brain ?-aminobutyric acid type A (GABAA) receptors. DCUK-OEt was shown to be a positive allosteric modulator (PAM) of GABA currents with ?1?2?2, ?1?3?2, ?5?3?2 and ?1?3? GABAA receptors, while having no significant PAM effect on ?? receptors or ?1?1?2, ?1?2?1, ?4?3?2 or ?4?3? receptors. DCUK-OEt modulation of ?1?2?2 GABAA receptors was not blocked by flumazenil. The subunit requirements for DCUK-OEt actions distinguished DCUK-OEt from other currently known modulators of GABA function (e.g., anesthetics, neurosteroids or ethanol). Simulated docking of DCUK-OEt at the GABAA receptor suggested that its binding site may be at the ??+??- subunit interface. In slices of the central amygdala, DCUK-OEt acted primarily on extrasynaptic GABAA receptors containing the ?1 subunit and generated increases in extrasynaptic "tonic" current with no significant effect on phasic responses to GABA. DCUK-OEt is a novel chemical structure acting as a PAM at particular GABAA receptors. Given that neurons in the central amygdala responding to DCUK-OEt were recently identified as relevant for alcohol dependence, DCUK-OEt should be further evaluated for the treatment of alcoholism.

SUBMITTER: Borghese CM 

PROVIDER: S-EPMC5524711 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature