A practical reference on GABA-A modulation: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-02-23 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
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.
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.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
There are some parallels between the chemistry of ammonia NH3 and water H2O. For example, the capacity of both compounds to be protonated to give NH4+ and H3O+ or deprotonated to give NH2− and OH−, with all of these able to be isolated in solid compounds. Nitrogen shares with both its horizontal neighbours a preference for forming multiple bonds, typically with carbon, oxygen, or other nitrogen atoms, through pπ–pπ interactions. Thus, for example, nitrogen occurs as diatomic molecules and therefore has very much lower melting (−210 °C) and boiling points (−196 °C) than the rest of its group, as the N2 molecules are only held together by weak van der Waals interactions and there are very few electrons available to create significant instantaneous dipoles. This is not possible for its vertical neighbours; thus, the nitrogen oxides, nitrites, nitrates, nitro-, nitroso-, azo-, and diazo-compounds, azides, cyanates, thiocyanates, and imino-derivatives find no echo with phosphorus, arsenic, antimony, or bismuth. By the same token, however, the complexity of the phosphorus oxoacids finds no echo with nitrogen. Setting aside their differences, nitrogen and phosphorus form an extensive series of compounds with one another; these have chain, ring, and cage structures. Table of thermal and physical properties of nitrogen (N2) at atmospheric pressure:
By 1906, there were 61 Lodges in Cuba. Independent Lodges who did not desire to recognize the authority of the Grand Lodge still existed in the Eastern half of the island. The Grand Lodge of Cuba considered these Lodges to be clandestine and irregular, completely unwilling to "...submit to Masonic law and cooperate to maintain the high reputation which Cuban Masonry has won after years of struggle..." Between 1902 and 1905, fifty thousand Spaniards from the Iberian Peninsula gained citizenship and residency in the new Cuba. Some of these were willing to join the Grand Lodge of Cuba.
A wound healing assay is a laboratory technique used to study cell migration and cell–cell interaction. This is also called a scratch assay because it is done by making a scratch on a cell monolayer and capturing images at regular intervals by time lapse microscopy. It is specifically a 2D cell migration approach to semi-quantitatively measure cell migration of a sheet of cells. This scratch can be made through various approaches, such as mechanical, thermal, or chemical damage. The purpose of this scratch is to produce a cell-free area in hopes of inducing cells to migrate and close the gap. The scratch test is ideal for cell types that migrate in collective epithelial sheets and is not generally useful for non-adherent cells. Specifically, this assay isn't ideal for chemotaxis studies.
Spinneys, which holds a 50-year lease with a 382,900 ft² cold storage distribution centre BRF (Brasil Foods), which operates a 1.6 million sq plant producing meat products and bread-based foods under the Sadia brand. Emirates Calcium Carbonate Factory, established under a 50-year agreement to supply products for oilfield industries Palletco, a manufacturing facility under a 50-year lease agreement. Apex Engineering Industries, an AED 90 million manufacturing facility for oil, gas and defence. Abundance Solar Panel Industries, an AED 55 million solar production plant. Global logistics companies, including DHL Global Forwarding and DSV, which provide logistics and supply chain services. Azizi Developments, which signed a 50-year land lease agreement to build 12 factories with an investment of AED 1 billion. Jiangsu Overseas Cooperation Investment Co. Ltd (JOCIC), established in 2017 to manage the China-UAE Industrial Capacity Cooperation Demonstration Zone. Built-to-suit
=== Microfibrilated cellulose === Micro cellulose (MFC) is a type of nanocellulose that is more heterogeneous than cellulose nanofibers or nanocrystals as it contains a mixture of nano- and micro-scale particles. The term is sometimes misused to refer to cellulose nanofibers instead.
Sources: en.wikipedia.org
== Specific varieties == Tripolite is the variety found in Tripoli, Libya. Bann clay is the variety found in the Lower Bann valley in Northern Ireland. Moler (mo-clay) is the variety found in northwestern Denmark, especially on the islands of Fur and Mors. Freshwater-derived food grade diatomaceous earth is the type used in United States agriculture for grain storage, as feed supplement, and as an insecticide. It is produced uncalcinated, has a very fine particle size, and is very low in crystal silica (<2%). Salt-water-derived pool / beer / wine filter grade is not suitable for human consumption or effective as an insecticide. Usually calcinated before being sold to remove impurities and undesirable volatile contents, it is composed of larger particles than the freshwater version and has a high crystalline silica content (>60%).
=== The Adventures of Professor D === In 2026, Ariely published a children's graphic novel titled Professor D Takes Control, illustrated by Omer Hoffman. It is the first in a planned three-part series. The book is about a character named Professor D, who "gets into all kinds of trouble" and "uses social science" to get out of it.
==== Mouse bioassay ==== The mouse bioassay (MBA) procedure developed by Yasumoto et al. is the official reference method used to analyse for YTX and lipophilic toxins including okadaic acid, dinophysistoxins (DSPs), azaspiracids, and pectenotoxins. The MBA involves injecting the extracted toxin into a mouse and monitoring the mouse survival rate; the toxicity of the sample can be subsequently deduced and the analyte concentration determined. This calculation is made on the basis that one mouse unit (MU) is the minimum quantity of toxin needed to kill a mouse in 24hours. The MU is set by regulating bodies at 0.05 MU/g of animal. The original Yasumoto MBA is subject to interferences from paralytic shellfish toxins and free fatty acids in solution, which cause false positive results. Several modifications to the MBA can be made to allow the test to be performed without these errors. The MBA, however, still has many drawbacks;
In this application, ion-exchange resins are used to remove poisonous (e.g. copper) and hazardous metal (e.g. lead or cadmium) ions from solution, replacing them with more innocuous ions, such as sodium and potassium, in the process cation and anion exchange resins are used to remove dissolved ions from the water. Few ion-exchange resins remove chlorine or organic contaminants from water – this is usually done by using an activated charcoal filter mixed in with the resin. There are some ion-exchange resins that do remove organic ions, such as MIEX (magnetic ion-exchange) resins. Domestic water purification resin is not usually recharged – the resin is discarded when it can no longer be used. These ion-exchange skids that are used and sized for 10 ML/day per bead can have cost upwards of US$1.5–2.5 million when implemented for industrial water treatment. Water of highest purity is required for many uses ranging from electronics to scientific experiments, as well as the production of superconductors, and within the nuclear industry, among others. Such water is produced using ion-exchange processes or combinations of membrane and ion-exchange methods. This method can prove to be expensive as the secondary waste handling cost can run on average US$0.10–0.20 per cubic meter.
The following day, Lee insisted that Peart's remarks had been taken out of context, and suggested he was "simply taking a break". Lifeson confirmed in 2016 that the R40 tour was the band's last large-scale tour. A documentary, Time Stand Still, was announced in November 2016. On January 16, 2018, Lifeson told The Globe and Mail that it was unlikely that Rush would play any more shows or record new material. He said, "We have no plans to tour or record anymore. We're basically done. After 41 years, we felt it was enough." In October 2018, Rolling Stone published an interview with Lee, who said:
Sources: en.wikipedia.org
It is commonly suggested by scholars that the EPRDF's decision to establish a federal administrative structure along ethnic lines was a move towards reinforcing its political dominance. By dividing the country and facilitating the creation of accompanying ethnically-based parties under the government's control, the TPLF (which represented less than 10% of the country's population) could intensify its hold on power. Dissatisfied opposition parties argued that this form of federalization was not appropriate for the country. For instance, the All Amhara People's Organisation (AAPO) and the Ethiopian Democratic Union Party expressed in 2000 that they preferred a strong unitary state with representation of the country's nationalities at the core. Other groups, such as the Oromo National Congress (ONC) and the Ethiopia Democratic Party (EDP), were not opposed to the idea of establishing a federal system, arguing that it set the foundation for regional autonomy, but believed that it was a mistake for it to conducted along ethnic lines.
==== Octopus vs. squid locomotion ==== Two of the categories of cephalopods, octopus and squid, are vastly different in their movements despite being of the same class. Octopuses are generally not seen as active swimmers; they are often found scavenging the sea floor instead of swimming long distances through the water. Squid, on the other hand, can be found to travel vast distances, with some moving as much as 2,000 km in 2.5 months at an average pace of 0.9 body lengths per second. There is a major reason for the difference in movement type and efficiency: anatomy. Both octopuses and squids have mantles (referenced above) which function towards respiration and locomotion in the form of jetting. The composition of these mantles differs between the two families, however. In octopuses, the mantle is made up of three muscle types: longitudinal, radial, and circular. The longitudinal muscles run parallel to the length of the octopus and they are used in order to keep the mantle the same length throughout the jetting process. Given that they are muscles, it can be noted that this means the octopus must actively flex the longitudinal muscles during jetting in order to keep the mantle at a constant length. The radial muscles run perpendicular to the longitudinal muscles and are used to thicken and thin the wall of the mantle. Finally, the circular muscles are used as the main activators in jetting. They are muscle bands that surround the mantle and expand/contract the cavity. All three muscle types work in unison to produce a jet as a propulsion mechanism.
== Early peptides == The observation that the chemokine CCL2 is potentially responsible for the recruitment of macrophages to atherosclerotic lesions initiated a campaign of research into the a class of molecules that would inhibit the trafficking of leukocytes and act as a new generation of anti-inflammatory agents. ‘Peptide 3’, a dodecapeptide section of CCL2, designed as an allosteric inhibitor of MCP-1 induced leukocyte chemotaxis, was quickly shown by leukocyte migration assay to be a functional inhibitor of many chemokines in vitro with similar potency. The potency of this peptide could be increased by cyclisation and the use of the reverse sequence of D-amino acids. This peptide is called NR58-3.14.3.
=== Genetically modified food === In 2015, Ayyadurai published a paper that applied systems biology, which uses mathematical modeling, to predict the chemical composition of genetically modified (GM) soybeans, and whether or not they were substantially equivalent to unmodified soybeans. The paper claimed that GM soybeans have lower levels of the antioxidant glutathione and higher levels of carcinogenic formaldehyde, making the modified soybean substantially different, contrary to previous safety assessments. Shortly after publication, Ayyadurai embarked on a speaking tour of the U.S. At the National Press Club, he said that genetic modification had "fundamentally modified the metabolic system of the soy", disrupting the "beautiful way of detoxifying [formaldehyde]" present in non-GM soy. The European Food Safety Agency evaluated the paper and determined that "the author's conclusions are not supported" due to the lack of information on the input into the model, the fact that the model was not validated and because no measurements of soybeans were made to establish whether GM soy actually contained elevated levels of formaldehyde. Plant scientist Kevin Folta noted that there was "no evidence ever published ... that shows a difference in formaldehyde between GM and non-GM varieties". Ayyadurai later cited the study as evidence of a lack of safety standards for GM foods and bet Monsanto a $10 million building if they could prove that they were safe.
Acrolein (systematic name: propenal) is the simplest unsaturated aldehyde. It is a colorless liquid with a foul and acrid aroma. The smell of burnt fat (as when cooking oil is heated to its smoke point) is caused by glycerol in the burning fat breaking down into acrolein. It is produced industrially from propylene and mainly used as a biocide and a building block to other chemical compounds, such as the amino acid methionine.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.