Study, Sep/20: Axonal mechanisms mediating GABA-A inhibition of dopamine release

The full title of this American study is "Axonal mechanisms mediating γ-aminobutyric acid receptor type A (GABA-A) inhibition of striatal dopamine release ".

https://pubmed.ncbi.nlm.nih.gov/32870779/

Abstract

Axons of dopaminergic neurons innervate the striatum where they contribute to movement and reinforcement learning. Past work has shown that striatal GABA tonically inhibits dopamine release, but whether GABA-A receptors directly modulate transmission or act indirectly through circuit elements is unresolved. Here, we use whole-cell and perforated-patch recordings to test for GABA-A receptors on the main dopaminergic neuron axons and branching processes within the striatum of adult mice. Application of GABA depolarized axons, but also decreased the amplitude of axonal spikes, limited propagation and reduced striatal dopamine release. The mechanism of inhibition involved sodium channel inactivation and shunting. Lastly, we show the positive allosteric modulator diazepam enhanced GABA-A currents on dopaminergic axons and directly inhibited release, but also likely acts by reducing excitation from cholinergic interneurons. Thus, we reveal the mechanisms of GABA-A receptor modulation of dopamine release and provide new insights into the actions of benzodiazepines within the striatum.

Full Study:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7462615/pdf/elife-55729.pdf

Thanks Lapis...

-Now does anyone want to interpret it for me..?? -in a 3 words or less kinda way..

Given my meds/sx, Im pretty sure I have no functional dopamine system atm..

Thanks Lapis...

-Now does anyone want to interpret it for me..?? -in a 3 words or less kinda way..

 

Given my meds/sx, Im pretty sure I have no functional dopamine system atm..

Yes, you're welcome, Cantfly! Let's see if some scientifically-minded BBs weigh in on this one. It's a mouse study, so that has to be kept in mind. Whether the results of this study can be extrapolated to humans is a big question that I have.