elevated plus maze 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 2026-02-19. Where a claim depends on a specific study, the study is described rather than over-claimed.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
| Property | Value | Notes |
|---|---|---|
| Principal proposed target | GABA-A receptor complex | Hypothesis derived mainly from animal pharmacology |
| Common behavioral assay | Elevated plus maze | Rodent test for anxiety-like behavior |
| Reported molecular marker | Hippocampal BDNF expression | Measured by immunoassay or mRNA quantification |
| Typical dosing route | Intranasal | Chosen to reduce first-pass metabolism |
| Reported plasma half-life | Minutes | Based on limited peptide stability data |
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
One aptamer, in particular, proved effective as a recognition element in an electrochemical sensor, enabling the detection of sGP and GP1.2 in solution, as well as GP1.2 within a membrane context. The results of this research point to the intriguing possibility that certain regions on protein surfaces may possess aptatropic qualities. Identifying the key features of such sites, in conjunction with improved 3-D structural predictions for aptamers, holds the potential to enhance the accuracy of predicting aptamer interaction sites on proteins. This, in turn, may help identify aptamers with a heightened likelihood of binding proteins with high affinity, as well as shed light on protein mutations that could significantly impact aptamer binding. This comprehensive understanding of the structure-based interactions between aptamers and proteins is vital for refining the computational predictability of aptamer-protein binding. Moreover, it has the potential to eventually eliminate the need for the experimental SELEX protocol.
Ethanol does induce non-lamellar phases (non-bilayer) but this process is concentration-dependent. On average the bilayers is preserved at approximately less than 10 mol%. Ethanol prefers to bond in the hydrophilic region near phosphate groups which could be contributed to its amphiphilic character. The effects of ethanol can be reversed or hindered in the presence of cholesterol (sterol compounds) It may be necessary to perform a future study to compare the maximum amount of cholesterol (30 mol%) obtained in the NNR study to varied concentrations of ethanol as depicted in the AMDS study to see if ethanol is still hindered in the presence of sterol compounds.
=== 2015 attack on security forces === On 7 April 2015, the CJNG ambushed and killed 15 Mexican police officers and seriously injured five others. The cartel carried out the attack as the police officers were driving along a mountain road in Jalisco, which was blocked by the CJNG with burning vehicles. Once the convoy of police officers was stopped in a vulnerable position, gunmen from the CJNG opened fire on them with sophisticated weaponry including machine guns and grenade launchers.
== Early life and education == Wayne Woolley was born in Raymond, Alberta, the son of Americans living in Canada. His extended family were prominent members of the Church of Jesus Christ of Latter-day Saints; his great-grandfather was Edwin Dilworth Woolley, was a prominent Latter-day Saint bishop in Salt Lake City. Wayne Woolley (as he was known) was a precocious child who finished high school at age 13, and completed an undergraduate degree in chemistry at the University of Alberta at age 19. He pursued graduate studies in the department of agricultural chemistry at the University of Wisconsin, where he earned his PhD in 1939. His graduate research with Conrad Elvehjem concerned nicotinic acid as a treatment for canine blacktongue, with implications for human pellagra.
==== Non-synthesizers ==== Some mammals have lost the ability to synthesize vitamin C, including simians and tarsiers, which together make up one of two major primate suborders, Haplorhini. This group includes humans. The other more primitive primates (Strepsirrhini) have the ability to make vitamin C. Synthesis does not occur in some species in the rodent family Caviidae, which includes guinea pigs and capybaras, but does occur in other rodents, including rats and mice. Synthesis does not occur in most bat species, but there are at least two species, frugivorous bat Rousettus leschenaultii and insectivorous bat Hipposideros armiger, that retain (or regained) their ability of vitamin C production. A number of species of passerine birds also do not synthesize, but not all of them, and those that do not are not clearly related; it has been proposed that the ability was lost separately a number of times in birds. In particular, the ability to synthesize vitamin C is presumed to have been lost and then later re-acquired in at least two cases. The ability to synthesize vitamin C has also been lost in about 96% of extant fish (the teleosts). Schistosomes (parasitic flatworms) cannot synthesize vitamin C and require it from their hosts in order to produce eggs; in both guinea pigs and in mice genetically engineered to be non-synthesizers, vitamin C deficiency prevents schistosomes from reproducing. In mice, it has additionally been found that vitamin C deficiency (even intermittent) prevents schistosomes from causing disease.
Sources: en.wikipedia.org
Factor VIII is bound to VWF while inactive in circulation; factor VIII degrades rapidly when not bound to VWF. Factor VIII is released from VWF by the action of thrombin. In the absence of VWF, factor VIII has a half-life of 1–2 hours; when carried by intact VWF, factor VIII has a half-life of 8–12 hours. VWF binds to collagen, e.g., when collagen is exposed beneath endothelial cells due to damage occurring to the blood vessel. Endothelium also releases VWF which forms additional links between the platelets' glycoprotein Ib/IX/V and the collagen fibrils VWF binds to platelet GpIb when it forms a complex with gpIX and gpV; this binding occurs under all circumstances, but is most efficient under high shear stress (i.e., rapid blood flow in narrow blood vessels, see below). VWF binds to other platelet receptors when they are activated, e.g., by thrombin (i.e., when coagulation has been stimulated). VWF plays a major role in blood coagulation. Therefore, VWF deficiency or dysfunction (von Willebrand disease) leads to a bleeding tendency, which is most apparent in tissues having high blood flow shear in narrow vessels. From studies it appears that VWF uncoils under these circumstances, decelerating passing platelets. Recent research also suggests that von Willebrand Factor is involved in the formation of blood vessels themselves, which would explain why some people with von Willebrand disease develop vascular malformations (predominantly in the digestive tract) that can bleed excessively.
=== Measurement in body fluids === Fluoxetine and norfluoxetine may be quantitated in blood, plasma, or serum to monitor therapy, confirm a diagnosis of poisoning in hospitalized persons, or assist in a medicolegal death investigation. Blood or plasma fluoxetine concentrations are usually in a range of 50–500 μg/L in persons taking the drug for its antidepressant effects, 900–3000 μg/L in survivors of acute overdosage, and 1000–7000 μg/L in victims of fatal overdosage. Norfluoxetine concentrations are approximately equal to those of the parent drug during chronic therapy but may be substantially less following acute overdosage since it requires at least 1–2 weeks for the metabolite to achieve equilibrium.
=== June === 2 June – Reform UK announces plans to cut "wasteful spending" in councils it controls with the establishment of what it describes as a Department of Government Efficiency (Doge), with Kent County Council the first area to have a Doge department. 4 June – In her first question to the prime minister during Prime Minister's Questions, Sarah Pochin, the newly elected Reform UK MP for Runcorn and Helsby, calls on Keir Starmer to introduce a ban of the wearing of burqas "in the interests of public safety". Her request is rejected by the prime minister, and described as "dumb" by Reform's chairman, Zia Yusuf. 5 June – Shadow Chancellor Mel Stride seeks to distance the Conservative Party from the September 2022 mini-budget of Liz Truss by saying the Conservatives will "never again" put the UK's economic stability at risk by making "promises we cannot afford". Conservative leader Kemi Badenoch announces plans to establish a commission to look at whether the UK should withdraw from some international agreements, such as the European Convention on Human Rights, which she says are binding hands of the UK government. Zia Yusuf resigns as chairman of Reform UK, saying working to get the party elected is no longer "a good use of [his] time". Technology entrepreneur Nathaniel Fried, seen as a key figure in the party's DOGE strategy, resigns along with Yusuf. The Hamilton, Larkhall and Stonehouse by-election takes place following the death of Christina McKelvie, and is won by Davy Russel for Scottish Labour, who take the seat from the Scottish National Party.
=== The Buck Institute for Research on Aging === In November 2016, Verdin became president and CEO of the Buck Institute for Research on Aging. The Buck Institute is the first independent research center focused solely on aging. As of 2022, it had an operating budget of $65 million a year and around 300 employees. The Buck's first human clinical trial, Buck Institute Ketone Ester (BIKE), was announced in 2023. In 2025, Verdin was named a scientific ambassador for Alliance for Longevity Science, Arts & Entertainment (ALSAE), a partner organization of the Buck Institute.
=== Golgi tendon organs === Houk and Simon provided one of the first mathematical models of a Golgi tendon organ receptor, modeling the firing rate of the receptor as a function of the muscle tension force. Just as for muscle spindles, they find that, as the receptors respond linearly to sine waves of different frequencies and has little variance in response over time to the same stimulus, Golgi tendon organ receptors may be modeled as linear time-invariant systems. Specifically, they find that the firing rate of a Golgi tendon organ receptor may be modeled as a sum of 3 decaying exponentials:
Sources: en.wikipedia.org
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.
Behavioral endpoints include time spent in open arms of the elevated plus maze and avoidance latencies. Biochemical endpoints include BDNF concentration, cytokine levels, and monoamine metabolite ratios in brain tissue.
Most published studies are small, originate from a limited number of laboratories, and lack independent replication. Dose-response relationships, measured brain exposure, and long-term outcomes are not well characterized.
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.