This is a working overview of BDNF, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-07-13 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.
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.
| 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 |
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
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 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.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
==== Reagent coflow prior to droplet formation ==== Reagents can be added at the time of droplet formation through a "co-flow" geometry. Reagent streams are pumped in separate channels and join at the interface with a channel containing the continuous phase, which shears and creates droplets containing both reagents. By changing the flow rates in reagent channels, reagent ratios within a droplet can be controlled.
=== Coiled coil filament === To improve the efficiency of the lamp, the filament usually consists of multiple coils of coiled fine wire, also known as a coiled coil. Light bulbs using coiled coil filaments are sometimes referred to as double-coil bulbs. For a 60-watt 120-volt lamp, the uncoiled length of the tungsten filament is usually 580 millimetres (22.8 in), and the filament diameter is 0.046 millimetres (0.0018 in). The advantage of the coiled coil is that there is less flow of gas in the bulb along the surface of the filament wire itself. Instead, gas only flows around the outside of whole coiled coil form, reducing both evaporation of the material and heat loss from the wire. The coiled-coil filament evaporates more slowly than a straight filament of the same surface area and light-emitting power, meaning the bulb lasts longer. The increased heat retained in the filament means that it runs hotter, which results in a more efficient light source.
==== Urquía Carreño takes back his office ==== While he was not able to enter the building, Urquía Carreño still refused to step down, and called the election a coup d'etat, citing that the Grand Lodge of Cuba had not followed the proper procedures to impeach him. He said that because the Grand Lodge had not provided the Office of Associations at the Ministry of Justice with the official minutes of the session in which they ejected him from his office, their decision was not legally binding. He was subsequently endorsed by the Ministry of Justice. To prevent Kessel Linares from carrying out the office of Grand Master, the Ministry of Justice blocked the bank accounts of the Grand Lodge, prohibited them from carrying out certain activities, and suspended the Grand Lodge of Cuba from their Office of Associations, which is the office of Justice that oversees the Registry of Associations. Urquía Carreño told the Grand Lodge that if they continued in their current course of action, there would be "...more drastic and harmful measures..." that the Ministry of Justice could pursue. Over the next several months resumed the normal work of the office of Grand Master. Urquía Carreño also leveled accusations against all those Freemasons who had spoken to the press about the situation, that they had broken their solemn covenants and vows of secrecy to the fraternity. State television channels then sided with Urquía Carreño, urging the public to remain calm.
==== Prerequisites for applying to a specialist training program ==== A physician practicing in Sweden may apply to a specialist training program (Swedish: Specialisttjänstgöring) after being licensed as a physician by The National Board of Health and Welfare. To obtain a license through the Swedish education system a candidate must go through several steps. First the candidate must successfully finish a five-and-a-half-year undergraduate program, made up of two years of pre-clinical studies and three and a half years of clinical postings, at one of Sweden's seven medical schools—Uppsala University, Lund University, The Karolinska Institute, The University of Gothenburg, Linköping University, Umeå University, or Örebro University—after which a degree of Master of Science in Medicine (Swedish: Läkarexamen) is awarded. The degree makes the physician eligible for an internship (Swedish: Allmäntjänstgöring) ranging between 18 and 24 months, depending on the place of employment. The internship is regulated by the National Board of Health and Welfare and regardless of place of employment it is made up of four main postings with a minimum of nine months divided between internal medicine and surgery—with no less than three months in each posting—three months in psychiatry, and six months in general practice. It is customary for many hospitals to post interns for an equal amount of time in surgery and internal medicine (e.g. six months in each of the two).
He also serves on the scientific advisory board for seven additional companies (Eisai, Kemxtree, Quanta Therapeutics, Inc., Alkermes, Inc, Nutcracker Therapeutics, Inc., Hongene Biotech Corporation, Shouxin, and Sage Therapeutics) and has consulted for over twenty more, including presently at Bristol-Meyers-Squibb, Gilead, and BASF Corporation. In 2014, Baran began a partnership with IKA, a laboratory equipment manufacturer, to bring to market equipment designed to standardize electrochemical protocols and make electrochemistry accessible to the average organic chemist. Three years after the partnership began, the ElectraSyn was presented at the American Chemical Society annual meeting. In the seven years since, the ElectraSyn and subsequent ElectraSyn 2.0 have been adopted by the synthetic community and utilized towards hundreds of research articles and patents.
Sources: en.wikipedia.org
==== Serotonin–norepinephrine reuptake inhibitors (SNRIs) ==== Duloxetine (Ariclaim; Cymbalta; LY-227942; LY-248686; Xeristar; Yentreve) – serotonin–norepinephrine reuptake inhibitor (SNRI) [40] Venlafaxine (Dobupal; Efexor XR; Effexor; Effexor XR; Elafax; WY-45030; WY-45651; WY-45655) – serotonin–norepinephrine reuptake inhibitor (SNRI) [41]
Oveporexton, sold under the brand name Orzeyful, is a medication used for the treatment of narcolepsy type 1. It is taken by mouth. The most common side effects include insomnia, increased urinary frequency, urgency to urinate, and increased saliva production. Oveporexton is an orexin OX2 receptor agonist. Oveporexton was approved for medical use in China in July 2026, and in the United States in August 2026. It is recommended for scheduling under the Controlled Substances Act and will be lawful to market in the US following the scheduling decision issued by the Drug Enforcement Administration.
Leconotide (INN; development codes CNSB004 and AM336; also known as ω-conotoxin CVID) is an ω-conotoxin peptide isolated from the venom of Conus catus which is under investigation as an analgesic drug for the treatment of pain conditions. It acts as an N-type voltage-gated calcium channel (Cav2.2) blocker and is highly selective for this channel over the related P/Q-type voltage-gated calcium channel (Cav2.1). Relative to ziconotide, leconotide is advantageous in that it is significantly less toxic, and for that reason can be administered intravenously as opposed to via intrathecal injection.
==== Color pigments ==== The pigments in the painting of the Kizil Caves have been analysed by X-ray diffraction analysis. The reds are primarily vermilion and red lead, which today are greatly discolored, and red ocher. Blue pigments are from lapis lazuli. Green pigments are from copper hydroxy chloride minerals such as atacamite. Brownish-black pigments are PbO2, obtained from the oxidation of red lead. White pigments were mainly obtained from gypsum.
== Appearances == Half-Life opens on Gordon Freeman as a research assistant at the Anomalous Materials wing of the Black Mesa Research Facility. After donning the Hazardous Environment suit for an experiment, Freeman survives an interdimensional "resonance cascade", taking up a crowbar as his signature weapon and fighting his way across the facility against both extradimensional invaders and hostile US marines to seal the rift. In Half-Life 2, after being kept in stasis for nearly two decades, Freeman battles the Combine Empire to liberate Earth. He gains legendary status as part of the resistance against the Combine forces and sparks a rebellion, ultimately destroying the Citadel, a major Combine stronghold. The G-Man rescues Freeman after this critical event, praising his accomplishments and placing him back in stasis. In Episode One, Gordon Freeman and Alyx Vance work to stabilize the Citadel's core to prevent a catastrophic explosion. In Episode Two, they work together to transport crucial data to close a forming super portal. After a revelation from the G-Man about saving Alyx, they learn about the Borealis, a research vessel with the potential to cause significant events. The game ends with Alyx mourning her father's death at the hands of a Combine Advisor. Half-Life: Alyx, set five years before Half-Life 2, follows Alyx Vance trying to locate Gordon. She infiltrates a Combine vault, believing it holds Gordon, but instead releases the G-Man.
Sources: en.wikipedia.org
On the other hand, if these organisms ultimately were able to survive outside of controlled space, they might have a particular benefit over natural organisms because they would be resistant to predatory living organisms or natural viruses, that could lead to an unmanaged spread of the synthetic organisms.
Peter Benenson (born Peter James Henry Solomon; 31 July 1921 – 25 February 2005) British lawyer, writer, pamphleteer, human rights activist and the founder of human rights group Amnesty International (AI); accepted the Pride of Britain Award for Lifetime Achievement in 2001 though he later rejected and denounced Amnesty International for its criticism of Israel. Benenson was the son of British-born Harold Solomon and Russian-born Flora Benenson, grandson of Russian financier Grigori Benenson (1860–1939); served in Intelligence Corps at the Ministry of Information and worked at Bletchley Park during World War II as a cryptographer. Leila Berg (12 November 1917 – 17 April 2012) was an English children's author, editor and play specialist. She was well known as a journalist and a writer on education and children's rights. Berg was a recipient of the Eleanor Farjeon Award. John Berger, Jewish father, convert to Roman Catholicism, (5 November 1926 – 2 January 2017) English art critic, novelist, painter and poet. Berger's essay on art criticism Ways of Seeing, is known as a foundation text employing deconstruction and feminist prisms of epistemology and ontology, questioning axiomatic assumptions about gender, racial prejudice and Orientalism, whilst introducing and debating prisms of Psychological projection, Reification (Marxism), False Consciousness, Commodity fetishism, Marx's theory of alienation and essentialism. He was a supporter of the Palestinian cause, and, focused on Israel and apartheid, a member of the Support Committee of the Russell Tribunal on Palestine.
=== Analgesia and wound management === Pain management and choice of analgesia is a challenging task in managing calciphylaxis. Pain is one of the most severe and pervasive symptoms of the disease and can be unresponsive to high-dose opioids. Fentanyl and methadone are preferred analgesics over morphine, since morphine breakdown produces active metabolites that accumulate in the body of patients with kidney failure. Adjunct medications such as gabapentin and ketamine may also be used for analgesia. In refractory cases, spinal anesthetics (nerve blocks) can be used for more comprehensive pain relief. Wound care for calciphylaxis lesions involves using appropriate dressings, wound debridement (removal of dead tissue), and prevention of infection. Wound infections lead to sepsis, which is one of the leading causes of death in patients with calciphylaxis. Surgical wound debridement carries increased risk for infection, so it should only be considered as therapy if the survival benefit outweighs the chances of continued wound non-healing and pain. Hyperbaric oxygen therapy may also be considered. There are some smaller retrospective studies that show the use of hyperbaric oxygen in improving delivery of oxygen to wounds, which improves blood flow and helps with wound healing.
The Administration had initially provided a fact sheet to describe the policy.) The PPD promised to elevate the role of development assistance within U.S. policy and rebuild "USAID as the U.S. Government's lead development agency." It also established an Interagency Policy Committee on Global Development led by the National Security Staff and added to U.S. development efforts an emphasis on innovation. To implement the PPD's instruction that "USAID will develop robust policy, planning, and evaluation capabilities," USAID re-created in mid-2010 a development planning office, the Bureau of Policy, Planning, and Learning. On November 23, 2010, USAID announced the creation of a new Bureau for Food Security to lead the implementation of President Obama's Feed the Future Initiative, which had formerly been managed by the State Department. On December 21, 2010, Secretary of State Clinton released the Quadrennial Diplomacy and Development Review (QDDR). Modeled after the military's Quadrennial Defense Review, the QDDR of 2010 reaffirmed the plan to re-build USAID's Foreign Service staffing while also emphasizing the increased role that staff from the State Department and domestic agencies would play in implementing U.S. assistance. In addition, it laid out a program for a future transfer of health sector assistance back from the State Department to USAID. The follow-on QDDR released in April 2015 reaffirmed the Administration's policies.
== Limitations and advancements == While reporter gene technology has become an essential component of molecular biology, its application still has limitations. One primary concern is the influence of genomic context on reporter expression. Reporter genes integrated into the genome can be subject to position-effect variegation, where the surrounding chromatin structure influences transcriptional activity. This can lead to inconsistent expression and complicate the interpretation of results, especially in stable cell lines and transgenic organisms. Additionally, reporter expression may not always accurately reflect the activity of the endogenous gene of interest due to differences in post-transcriptional regulation, mRNA stability, or translational efficiency. Another common limitation is the cellular burden that reporter expression may impose. High levels of reporter protein production, such as fluorescent proteins or luciferases, can divert cellular resources, potentially impacting normal metabolism or physiology. This is particularly problematic in sensitive systems like stem cells or primary cell cultures, where even subtle changes in metabolism can influence cell behavior. Additionally, some reporter systems, like luciferase assays, require the addition of exogenous substrates (e.g., luciferin), adds complexity and may reduce reproducibility, particularly in live animal models where substrate availability can vary. To address these challenges, several innovations have improved the reliability and flexibility of reporter gene technologies.
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.
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.