GABA-A receptor is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-07-12. Where a claim depends on a specific study, the study is described rather than over-claimed.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
Amat-Mamu (fl. c. 1736 BC) was a Babylonian nadītu priestess in Sippar from the 18th century BC who was the subject of legal proceedings involving her inheritance. Amat-Mamu was chosen as the heir of fellow nadītu Belessunu, who bequeathed Amat-Mamu her land and slaves. In exchange, Amat-Mamu was to provide for Belessunu until her death. The estate was claimed by two of Belessunu's cousins, but the mayor ruled in favor of Belessunu and Amat-Mamu. Amat-Mamu then lost the deeds when they were kept in her uncle's home, requiring her to have them reconstituted in a new tablet. This tablet was preserved, and its description of Amat-Mamu's inheritance provides insight into Babylonian inheritance practices.
=== 20th century === In 1916, during the First World War, a German Zeppelin airship was shot down during an aerial battle over Billericay. During its fiery demise, it narrowly missed the High Street, crashing into a field off Greens Farm Lane. A plaque was erected at the site in 2016, to commemorate 100 years since the incident. Parts of the aluminium frame can be seen at the Cater Museum in the High Street. Recent research has indicated that this may be identified with the 'ghost Zeppelin' of Tonbridge, which was allegedly seen floating over that town earlier in the day. The former workhouse became St Andrew's Hospital, which housed the internationally renowned Regional Plastic Surgery and Burns Unit from 1973, until this was relocated to Broomfield Hospital, north of Chelmsford, in April 1998. Most of the hospital was redeveloped subsequently into housing, with the listed old workhouse buildings being converted to residential use.
NAD(P)H quinone oxidoreductase 1 (Nqo1) is a prototypical NRF2 target protein which catalyzes the reduction and detoxification of highly reactive quinones that can cause redox cycling and oxidative stress. Glutamate-cysteine ligase catalytic subunit (GCLC) and glutamate-cysteine ligase regulatory subunit (GCLM) form a heterodimer, which is the rate-limiting step in the synthesis of glutathione (GSH), a very powerful endogenous antioxidant. Both Gclc and Gclm are characteristic NRF2 target genes, which establish NRF2 as a regulator of glutathione, one of the most important antioxidants in the body. Sulfiredoxin 1 (SRXN1) and Thioredoxin reductase 1 (TXNRD1) support the reduction and recovery of peroxiredoxins, proteins important in the detoxification of highly reactive peroxides, including hydrogen peroxide and peroxynitrite. Heme oxygenase-1 (HMOX1, HO-1) is an enzyme that catalyzes the breakdown of heme into the antioxidant biliverdin, the anti-inflammatory agent carbon monoxide, and iron. HO-1 is a NRF2 target gene that has been shown to protect from a variety of pathologies, including sepsis, hypertension, atherosclerosis, acute lung injury, kidney injury, and pain. Conversely, induction of HO-1 has been shown to exacerbate early brain injury after intracerebral hemorrhage. The glutathione S-transferase (GST) family includes cytosolic, mitochondrial, and microsomal enzymes that catalyze the conjugation of GSH with endogenous and xenobiotic electrophiles.
Sources: en.wikipedia.org
=== Barriers to access === In the US, the list price for a long-acting injectable form is five to 20 times as much as a daily pill. This has reduced the number of people who are able to get a single monthly dose, instead of daily pills. Some jails consider the more expensive form a positive tradeoff: a single monthly injection may be simpler and easier for the staff to manage than daily trips to the dispensary to have a nurse provide a pill and make sure that it has been swallowed.
== Society == In 2013, the US Congress passed the Recalcitrant Cancer Research Act, which mandated increased attention to certain recalcitrant cancers (cancers having a 5-year relative survival rate of less than 50%), including small cell lung cancer. That led to the National Cancer Institute supporting small cell-specific research.
On April 3, 2026 (Good Friday), the Pentagon hosted a Protestant service in the Pentagon chapel. An email sent by Air Force leaders stated, "Just a friendly reminder: There will be a Protestant Service (No Catholic Mass) for Good Friday today at the Pentagon Chapel." At least one employee stated that they felt Catholics were not welcome. A 40-year Pentagon employee stated that this is the first time that a Catholic Good Friday service was not offered at the Pentagon Chapel.
Sources: en.wikipedia.org
On television, d'Abo played Ta'Ra, an alien medical officer in the science fiction miniseries Something Is Out There (1988), which was followed by a six-episode NBC mini-series of the same name, and she played Anne Summerton in the TV adaptation of Jeffrey Archer's novel Not a Penny More, Not a Penny Less (1990) directed by Clive Donner. D'Abo had a supporting role as a pretentious stained-glass artist in the low-budget British comedy Leon the Pig Farmer (1992). She appeared in the 1994 film The Browning Version and starred in Timelock (1996). D'Abo has had roles in various low-budget, straight-to-video action, horror and fantasy films such as Tomcat: Dangerous Desires (1992), as well as guest roles on television shows Tales from the Crypt (1993), Red Shoe Diaries (1992) and Murder, She Wrote (1992). She reunited with her James Bond director John Glen for a guest-starring role on the television series Space Precinct and for the feature film The Point Men (2001). Glen later said that he cast her in three different projects was because she was one of his favourite actresses. She played the mother of Lara (played by Keira Knightley) in the television miniseries version of Doctor Zhivago (2002), and she was Queen Hecuba in the Emmy-nominated miniseries Helen of Troy (2003). She had a small role in the French film L'Enfer (Hell, 2005), directed by Danis Tanovic whose stars included fellow Bond Girl Carole Bouquet. D'Abo and John Cork wrote the book Bond Girls Are Forever, published in 2002, which is a tribute to the women who have played the role of a Bond girl.
The wool is left to lie in soak for five hours, and then, after carding it, it is thrown in again, until it has fully imbibed the colour. Archaeological data from Tyre indicate that the snails were collected in large vats and left to decompose. This produced a hideous stench that was mentioned by ancient authors. Not much is known about the subsequent steps, and the actual ancient method for mass-producing the two murex dyes has not yet been successfully reconstructed; this special "blackish clotted blood" colour, which was prized above all others, is believed to be achieved by double-dipping the cloth, once in the indigo dye of H. trunculus and once in the purple-red dye of B. brandaris.
=== In U.S. drinking water === In 2000, perchlorate contamination beneath the former flare manufacturing plant Olin Corporation Flare Facility, Morgan Hill, California was first discovered several years after the plant had closed. The plant had used potassium perchlorate as one of the ingredients during its 40 years of operation. By late 2003, the State of California and the Santa Clara Valley Water District had confirmed a groundwater plume currently extending over nine miles through residential and agricultural communities. The California Regional Water Quality Control Board and the Santa Clara Valley Water District have engaged in a major outreach effort, a water well testing program has been underway for about 1,200 residential, municipal, and agricultural wells. Large ion exchange treatment units are operating in three public water supply systems which include seven municipal wells with perchlorate detection. The potentially responsible parties, Olin Corporation and Standard Fuse Incorporated, have been supplying bottled water to nearly 800 households with private wells, and the Regional Water Quality Control Board has been overseeing cleanup efforts. The source of perchlorate in California was mainly attributed to two manufacturers in the southeast portion of the Las Vegas Valley in Nevada, where perchlorate has been produced for industrial use.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.