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 is the brute-force receptor activation a benzodiazepine uses.
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 non-benzodiazepine site 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 the expression of 45 genes one hour after dosing, 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. That is the whole of the finding: the combination behaves differently, not that Selank blocks the benzodiazepine. It flags why combining the two is pharmacologically unpredictable and should not be assumed additive. Olanzapine belongs in a separate sentence and runs the other way: the only olanzapine result on record is that Selank may enhance its effect on gene expression in cultured IMR-32 cells.