How it calms: GABA & enkephalin
Selank's anti-anxiety effect rests on two well-studied levers: an indirect influence on the GABA system and the…
Calming the brain without hijacking it
Selank's anti-anxiety effect rests on two well-studied levers: an indirect influence on the GABA system and the inhibition of enzymes that break down the body's own calming opioid peptides. Neither lever works the way a benzodiazepine does, by strongly amplifying GABA at the benzodiazepine site.
This unit unpacks both mechanisms with their primary English-language evidence, showing how Selank turns up the brain's existing calm signals rather than forcing new ones.
Key terms
The indirect GABA lever
GABA is the brain's main calming neurotransmitter, and its GABA-A receptors are where benzodiazepines act. Selank influences this system too, but through a fundamentally indirect route: it modulates GABA binding at a site its authors judge apparently not the same as the benzodiazepine site (possibly partly overlapping), and it changes the expression of GABA-related genes over hours.
The two routes reinforce a single theme: Selank re-tunes GABA signaling rather than seizing it. Radioligand work (Vyunova and colleagues) describes it as a positive allosteric modulator of [3H]GABA binding. In rat frontal cortex, Volkova and colleagues found significant changes in 45 genes one hour after Selank or GABA, with Selank itself moving 29 of 77 genes, in a pattern that correlated strongly with GABA's own at one hour (r = 0.86) and then inverted by three hours (r = -0.39). The resemblance to GABA is therefore time-limited rather than general. In IMR-32 neuroblastoma cells, Filatova and colleagues found no change in the mRNA levels of the genes studied under Selank alone, while Selank almost completely suppressed the changes GABA produced. That contrast is itself the argument for an indirect, modulatory action rather than a direct transcriptional one.
AdvancedThe benzodiazepine combination is not simply additive
The radioligand authors report that the joint action of Selank and some benzodiazepines regulates [3H]GABA binding in a specific manner that is not cumulative and differs from either substance individually, and that Selank is able to block the modulatory activity of diazepam and olanzapine in that binding assay. That is a membrane-binding result, not a clinical one, and it flags why combining the two is pharmacologically unpredictable and should not be assumed additive. The olanzapine picture is mixed: in the binding work Selank blocked olanzapine's modulatory activity, while in cultured IMR-32 cells Selank may enhance olanzapine's effect on gene expression.