stress response: nootropics and compounds | sci-wiki

Deoxycorticosterone

Deoxycorticosterone (11-deoxycorticosterone, 21-hydroxyprogesterone; also called cortexone or desoxycortone) is an endogenous steroid hormone made by the adrenal cortex that functions both as a mineralocorticoid and as the metabolic precursor to a potent neurosteroid. Acting through the mineralocorticoid receptor (a ligand-activated transcription factor that governs sodium and water balance), it promotes renal salt retention with an affinity close to that of aldosterone. Its principal relevance to neuropharmacology is as the parent compound of 3-alpha,5-alpha-tetrahydrodeoxycorticosterone (THDOC), a positive allosteric modulator of the GABA-A receptor (the brain's main inhibitory chloride channel) that is released during stress and shapes seizure threshold, anxiety, and hypothalamic-pituitary-adrenal (HPA) axis activity. Deoxycorticosterone should not be confused with the psychedelic amphetamine also abbreviated DOC (2,5-dimethoxy-4-chloroamphetamine), which is an entirely unrelated compound.

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Nootropic

MAP4343

MAP4343 (3β-methoxypregnenolone) is a synthetic derivative of the endogenous neurosteroid pregnenolone in which the 3β-hydroxyl group is replaced by a methyl ether, developed by the French steroid pharmacologist Étienne-Émile Baulieu and the biotechnology company Mapreg. Unlike classical neurosteroids that modulate ligand-gated ion channels, MAP4343 acts on microtubule-associated protein 2 (MAP2; a structural protein that governs the assembly and stability of neuronal microtubules), where it promotes tubulin polymerization and restores microtubule dynamics. It has been investigated as a novel, mechanistically distinct antidepressant and anti-addiction candidate, showing rapid and durable antidepressant-like effects in rodent and tree shrew stress models and having advanced into early clinical development. As of the mid-2020s it remains an investigational agent without regulatory approval.

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Neurosteroid

Org 34517

Org 34517 targeted a different piece of the depression puzzle entirely, the glucocorticoid receptor, on the theory that chronically elevated cortisol signaling drives depressive symptoms, especially in psychotic and melancholic depression where HPA-axis dysregulation is most pronounced. Organon (later folded into Merck/Schering-Plough) took it into Phase III, and an early paroxetine-controlled trial in 142 patients showed comparable antidepressant effects with a notable edge in patients who ran hypercortisolaemic. Despite that promising signal, the program stalled inside the corporate mergers that consumed Organon in the late 2000s, and the compound resurfaced years later, rebranded as PT-150, in the hands of a small biotech pursuing it for entirely different indications. It is one of the clearer cases of a molecule losing momentum not to failed science, but to a failed company.

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Neurosteroid

THDOC

THDOC (3-alpha,5-alpha-tetrahydrodeoxycorticosterone) is an endogenous neurosteroid (a steroid that acts rapidly on neuronal membrane receptors rather than on classical nuclear hormone receptors) and the fully reduced 3-alpha,5-alpha metabolite of the adrenal steroid deoxycorticosterone. It is one of the most potent naturally occurring positive allosteric modulators (compounds that amplify a receptor's response to its own transmitter) of the GABA-A receptor, the brain's principal inhibitory chloride ion channel, where it enhances both fast synaptic and sustained extrasynaptic inhibition. Because its synthesis is driven by adrenocorticotropic hormone and by acute stress, THDOC is regarded as a stress-responsive inhibitory neurosteroid that provides negative feedback on the hypothalamic-pituitary-adrenal axis and transiently raises the seizure threshold. Alongside allopregnanolone, it is a prototypical member of the stress-derived GABAergic neurosteroid family.

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