@Redefining differential roles of MAO-A in dopamine degradation and MAO-B in tonic GABA synthesis (Cho et al. 2021 Jul)

2022-04-24: reference:

@Redefining differential roles of MAO-A in dopamine degradation and MAO-B in tonic GABA synthesis (Cho et al. 2021 Jul) #

Novel research on MAO-B not, in fact, degrading dopamine at all, but instead: Striatal astrocytic GABAergic inhibition!
WTF does this mean for Amphetamines?
*It has been demonstrated that MAO-B-deficient mice show no difference in striatal DA levels compared with wild-type mice. Acute treatment with Selegiline.. has been reported to be ineffective in altering the striatal efflux of DA.
It has been previously reported that MAO-B inhibition shows only a marginal effect of blocking DA degradation in rat models of Parkinson’s, while MAO-A inhibition shows a dramatic effect
*Although these accumulating lines of evidence have cast doubt on the major role of MAO-B in DA degradation, MAO-B is still widely believed to be involved in DA degradation due to the positive therapeutic effect of MAO-B inhibitors in PD patients.

So is MAO-B a misnomer? Should it be called something else if it in fact does not oxidize monoamines…?

MAOB mediates the aberrant synthesis of GABA and hydrogen peroxide (H2O2) in reactive astrocytes of Parkinson’s disease (PD). Astrocytic GABA tonically suppresses the dopaminergic neuronal activity, whereas H2O2 aggravates astrocytic reactivity and dopaminergic neuronal death.