Chronic α5-GABA-A Receptor Potentiation Promotes Mouse Adult Hippocampal Neurogenesis

Area of Science:

• Neuroscience
• Cell Biology
• Pharmacology

Background:

• Adult hippocampal neurogenesis (AHN) is crucial for cognitive and mood-related behaviors.
• Augmenting α5-γ-Aminobutyric acid type A (GABAA) receptor function shows promise for neurotrophic effects.
• The impact of α5-GABAA receptor modulation on AHN is not well understood.

Purpose of the Study:

• To investigate the effect of a novel α5-GABAA-R positive allosteric modulator (α5-PAM), GL-II-73, on adult mouse hippocampal neurogenesis.
• To compare the impact of GL-II-73 on AHN with fluoxetine, a known enhancer of neurogenesis.

Main Methods:

• Adult male mice were treated for 6 weeks with either GL-II-73 (α5-PAM) or fluoxetine.
• Cell proliferation was assessed using Ki67.
• Newborn neuron survival and maturation were evaluated using 5-Bromo-2´-Deoxyuridine (BrdU) retention and co-labeling with DCX and NeuN.

Main Results:

• Chronic treatment with GL-II-73 significantly increased neuronal progenitor proliferation in the dentate gyrus (DG).
• GL-II-73 enhanced the survival of adult-born granule cells.
• The maturation rate of young adult-born neurons was also increased by GL-II-73 treatment.

Conclusions:

• GL-II-73, an α5-GABAA-R positive allosteric modulator, effectively stimulates all stages of adult hippocampal neurogenesis.
• The neurogenic effects of GL-II-73 are comparable to those of fluoxetine.
• Targeting α5-GABAA receptors represents a potential therapeutic strategy for enhancing neurogenesis.