Neuroscience Research

The East-West regulatory split is unusual enough to deserve closer examination. Semax was developed at the Institute of Molecular Genetics (Russian Academy of Sciences) in the 1980s, derived from ACTH(4-10) — a hormone fragment that retains the behavioral and neurotropic activity of full-length ACTH without its corticotropic effects. The compound entered Russian clinical use in 1996 as a nasal drop preparation for stroke, traumatic brain injury, and cognitive disorders. Selank, developed in parallel by the same group, is a synthetic analog of tuftsin (a tetrapeptide cleaved from IgG Fc) and was registered in Russia in 2009 as an anxiolytic. Both compounds have decades of Russian clinical and preclinical literature but remain investigational outside that regulatory framework. This is the unusual case where the research peptide field intersects with actual approved pharmaceutical use in one jurisdiction while remaining experimental elsewhere.

Semax: ACTH Fragment Without the Corticotropic Effects

The original observation behind Semax was that small fragments of ACTH retained neurotropic activity — memory enhancement, attention, neuroprotection — without driving cortisol release. Semax is the heptapeptide MEHFPGP, corresponding to ACTH(4-10) with proline-glycine-proline added at the C-terminus to confer resistance to proteolytic degradation. The compound's most-cited effect is on BDNF signaling: a single intranasal dose triples hippocampal BDNF mRNA expression within hours, with downstream increases in TrkB phosphorylation and CREB activation. The mechanism extends beyond BDNF — Semax modulates dopaminergic and serotonergic systems, affects expression of immediate-early genes (c-fos, c-jun), and shows neuroprotective effects in cerebral ischemia and oxidative stress models. The 2025 study in Acta Naturae extended this work into the APPswe/PS1dE9 Alzheimer's-model mouse line, examining cognitive endpoints and amyloid pathology — representative of the continued mechanistic exploration of the compound.

Selank: Tuftsin Analog and GABAergic Anxiolytic

Selank is the heptapeptide TKPRPGP, with the first four residues corresponding to tuftsin (TKPR) — a tetrapeptide derived from the Fc fragment of IgG and originally characterized for its immunomodulatory activity. Selank retains some immunomodulatory effects but is primarily studied for anxiolytic and nootropic properties. The mechanism involves modulation of the GABAergic system — Selank increases expression of GABA-A receptor subunits in stress-relevant brain regions and shows benzodiazepine-like behavioral effects without the sedation, tolerance, or dependence typically associated with benzodiazepines. Effects on serotonergic, dopaminergic, and noradrenergic systems have also been characterized. The compound is studied in elevated plus maze, light-dark box, and chronic mild stress models for anxiety endpoints, and in passive avoidance and Morris water maze tasks for memory effects.

PE-22-28: TREK-1 Modulation and BDNF Pathway

PE-22-28 is a peptide derived from spadin, a 17-amino acid peptide originally identified as a fragment of sortilin. Spadin and its shorter analog PE-22-28 act as selective blockers of TREK-1, a two-pore-domain potassium channel (K2P) involved in resting membrane potential and neuronal excitability. TREK-1 knockout mice show resistance to depression-like behaviors, which provided the rationale for developing TREK-1 inhibitors as research tools for antidepressant biology. PE-22-28 produces antidepressant-like effects in standard rodent models (forced swim test, tail suspension test, chronic unpredictable stress) and shows neuroprotective signal in cellular and animal models. Downstream effects include increased BDNF expression and TrkB activation — which is why the compound is sometimes described as having "BDNF-like" functional effects despite acting through a potassium channel mechanism rather than directly binding TrkB. The compound was characterized by Djillani and colleagues in the 2010s and remains in active preclinical investigation.

Cerebrolysin and the Broader Russian Neuropeptide Tradition

Beyond Semax and Selank, the broader Eastern European neuropeptide research tradition includes Cerebrolysin (a porcine brain-derived peptide preparation used clinically in many countries for stroke and Alzheimer's), Cortexin (another brain-derived preparation), and various Khavinson short peptides (Cortagen, Pinealon) with neuroactive applications. The structural feature uniting much of this research is short peptide chemistry derived from natural biological sources, often with empirical clinical development preceding mechanistic characterization — a different research model than the Western biotech approach of target identification followed by rational drug design.

Research Models Commonly Used

Standard in vivo neuroscience peptide research uses MCAO (middle cerebral artery occlusion) for ischemic stroke, photothrombotic stroke models for focal cortical injury, TBI models (controlled cortical impact, weight-drop), Aβ injection or APPswe/PS1dE9 transgenic lines for Alzheimer's research, and 6-OHDA or MPTP lesions for Parkinson's models. Behavioral endpoints include Morris water maze and Barnes maze (spatial learning), novel object recognition (recognition memory), elevated plus maze and open field (anxiety), forced swim test and tail suspension (depression-like behavior), and rotarod and beam walking (motor function). In vitro work uses primary hippocampal and cortical neurons for survival and plasticity studies, SH-SY5Y and Neuro2a cell lines for screening, and oxygen-glucose deprivation models for ischemia-reperfusion biology.

Frequently Asked Questions

Reference Points for Further Reading

For Semax, the foundational mechanistic work comes from the Myasoedov, Levitskaya, and Ashmarin groups at the Institute of Molecular Genetics, Russian Academy of Sciences — the original characterization papers from the 1990s-2010s are concentrated in Russian-language sources but also published in Bulletin of Experimental Biology and Medicine and Acta Naturae. For Selank, the same institute's publications on tuftsin analog development cover the mechanism foundation. For TREK-1 modulation and PE-22-28, the Djillani, Mazella, and Borsotto papers (multiple, 2014-2017) characterize the spadin-derived compound class. For broader neuropeptide research, the Sapolsky review series on stress neurobiology and the Duman and Aghajanian publications on synaptic plasticity in depression provide context for how peptide effects connect to broader neuroscience frameworks.

All compounds in this catalog are intended for in vitro and preclinical research use only. None are approved by the FDA or EMA for therapeutic use in humans, though Semax and Selank hold pharmaceutical registration in the Russian Federation for specified clinical indications. Clinical and regulatory information referenced on this page describes research and regulatory status in jurisdictions outside the US/EU and is provided as scientific context, not as claims for the research compounds offered here. Compounds affecting CNS function require careful research protocols, as effects can be context-dependent and vary with neurological state.