BDNF comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-12-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
| 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 |
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Critics considered the order an effort to intimidate ICC civil servants from proceeding with its investigation and accused the administration of targeting the two prosecutors, both of African origin, based on their race. The U.S. District Court for the Southern District of New York granted a preliminary injunction blocking the sanctions in January 2021, through a challenge to the order brought by four dual-national American law professors and the Open Society Justice Initiative. (The Biden administration lifted the ICC sanctions in April 2021.) Also in September 2020, Trump used the IEEPA to order the removal of social media platforms TikTok and WeChat from U.S. app stores as well as prohibit domestic business transactions involving their respective China-based parent companies ByteDance and Tencent; the restrictions would have become applicable to TikTok unless it was sold to an American company within 45 days of the executive order's issuance. Observers (including Trump administration critics and many TikTok users) raised First Amendment concerns with the executive order and suggested that, while national security concerns were cited to justify them, the sanctions were prompted by the administration's hostile relations toward China in general and retaliation against TikTok in particular. This retaliation was claimed to be for certain anti-Trump content hosted by the app.
=== Oceania === The Lapita culture, active across a large area of the Pacific Ocean around 1000 BC, made widespread use of obsidian tools and engaged in long distance obsidian trading. The complexity of the production technique for these tools, and the care taken in their storage, may indicate that beyond their practical use they were associated with prestige or high status. Obsidian was also used on Rapa Nui (Easter Island) for edged tools such as mataia and the pupils of the eyes of their Moai (statues), which were encircled by rings of bird bone. Obsidian was used to inscribe the Rongorongo glyphs.
The four substrates of this enzyme are cinnamic acid, reduced nicotinamide adenine dinucleotide phosphate (NADPH), oxygen, and a proton. Its products are p-coumaric acid, oxidised NADP+, and water. It participates in phenylalanine metabolism and phenylpropanoid biosynthesis, especially of flavonoids in plants. The enzyme is a cytochrome P450 protein containing heme. It requires a partner cytochrome P450 reductase for functional expression. This uses nicotinamide adenine dinucleotide phosphate (NADPH).
With Robert J. Flaherty's Nanook of the North in 1922, documentary film embraced romanticism. Flaherty filmed a number of heavily staged romantic documentary films during this time period, often showing how his subjects would have lived 100 years earlier and not how they lived right then. For instance, in Nanook of the North, Flaherty did not allow his subjects to shoot a walrus with a nearby shotgun, but had them use a harpoon instead. Some of Flaherty's staging, such as building a roofless igloo for interior shots, was done to accommodate the filming technology of the time. Paramount Pictures tried to repeat the success of Flaherty's Nanook and Moana with two romanticized documentaries, Grass (1925) and Chang (1927), both directed by Merian C. Cooper and Ernest Schoedsack.
Sources: en.wikipedia.org
=== Pain === Preclinical data support the notion that Substance P is an important element in pain perception. The sensory function of Substance P is thought to be related to the transmission of pain information into the central nervous system. Substance P coexists with the excitatory neurotransmitter glutamate in primary afferents that respond to painful stimulation. Substance P and other sensory neuropeptides can be released from the peripheral terminals of sensory nerve fibers in the skin, muscle, and joints. It is proposed that this release is involved in neurogenic inflammation, which is a local inflammatory response to certain types of infection or injury. Unfortunately, the reasons why NK1 receptor antagonists have failed as efficacious analgesics in well-conducted clinical proof of concept studies have not yet been persuasively elucidated.
East Germany closed itself to the sporting world in May 1965. In 1977 the shot-putter Ilona Slupianek, who weighed 93 kg, failed a test for anabolic steroids at the European Cup meeting in Helsinki and thereafter athletes were tested before they left the country. At the same time, the Kreischa testing laboratory near Dresden passed into government control; it reputedly made around 12,000 tests a year on East German athletes but without any being penalised. The International Amateur Athletics Federation (IAAF) suspended Slupianek for 12 months, a penalty that ended two days before the European championships in Prague. In the reverse of what the IAAF hoped, sending her home to East Germany meant she was free to train unchecked with anabolic steroids, if she wanted to, and then compete for another gold medal, which she won. After that, almost nothing emerged from the East German sports schools and laboratories. A rare exception was the visit by the sports-writer and former athlete, Doug Gilbert of the Edmonton Sun, who said:
Adverse effects have been documented from vitamin B6 dietary supplements, but never from food sources. Even though it is a water-soluble vitamin and is excreted in the urine, doses of pyridoxine in excess of the dietary upper limit (UL) over long periods cause painful and ultimately irreversible neurological problems. The primary symptoms are pain and numbness of the extremities. In severe cases, motor neuropathy may occur with "slowing of motor conduction velocities, prolonged F wave latencies, and prolonged sensory latencies in both lower extremities", causing difficulty in walking. Sensory neuropathy typically develops at doses of pyridoxine in excess of 1,000 mg per day. As noted above, in 2023 the European Food Safety Commission set an adult UL at 12 mg/day. While Australia has set an upper limit of 50 mg/day, the Therapeutic Goods Administration requires a label warning about peripheral neuropathy if the daily dose is predicted to exceed 10 mg/day.
In October 2011, a Bowery Historic District was registered with the New York State Register of Historic Places and therefore was automatically nominated for listing on the National Register of Historic Places. A grassroots community organization named Bowery Alliance of Neighbors (BAN) in association with the community-based housing organization called the Two Bridges Neighborhood Council led the effort for creation of the historic district. The designation means that property owners will have financial incentives to restore rather than demolish old buildings on the Bowery. BAN was recognized for its preservation efforts with a Village Award from the Greenwich Village Society for Historic Preservation in 2013. The historic district runs from Chatham Square to Astor Place on both sides of the Bowery.
Vaccinations given to children, adolescents, or adults are generally safe. Adverse effects, if any, are generally mild. The rate of side effects depends on the vaccine in question. Some common side effects include fever, pain around the injection site, and muscle aches. Additionally, some individuals may be allergic to ingredients in the vaccine. The MMR vaccine is rarely associated with febrile seizures. Host-("vaccinee")-related determinants that render a person susceptible to infection, such as genetics, health status (underlying disease, nutrition, pregnancy, sensitivities or allergies), immune competence, age, and economic impact or cultural environment can be primary or secondary factors affecting the severity of infection and response to a vaccine. Elderly (above age 60), allergen-hypersensitive, and obese people have susceptibility to compromised immunogenicity, which prevents or inhibits vaccine effectiveness, possibly requiring separate vaccine technologies for these specific populations or repetitive booster vaccinations to limit virus transmission. Severe side effects are extremely rare. Varicella vaccine is rarely associated with complications in immunodeficient individuals, and rotavirus vaccines are moderately associated with intussusception. At least 19 countries have no-fault compensation programs to provide compensation for those with severe adverse effects of vaccination. The United States' program is known as the National Childhood Vaccine Injury Act, and the United Kingdom employs the Vaccine Damage Payment.
Sources: en.wikipedia.org
=== US introduction === The Turkestan cockroach was first noticed in the US in 1978, around the former Sharpe Army Depot in California, followed shortly after by appearances at Fort Bliss in Texas and several other military bases. Researchers believe the species arrived on military equipment returning from Central Asia, perhaps Afghanistan. Since then the species has been rapidly replacing the common oriental cockroach (Blatta orientalis) in urban areas of the Southwestern United States “as the most important peri-domestic species”, with advantages of laying more eggs and maturing more quickly than the oriental cockroach. “They typically inhabit in-ground containers such as water meter, irrigation, and electrical boxes, raises of concrete, cracks and crevices, and hollow block walls.” They are well established in the Southwest and parts of the Southeast, and have been reported in the Northeast. It has become established in California.
The GARS1 gene encodes the enzyme glycyl-tRNA synthetase (GlyRS), which belongs to the class II group of aminoacyl-tRNA synthetases. This enzyme is essential in the process of protein synthesis, facilitating the bonding of the amino acid glycine to its corresponding transfer RNA (tRNA). Through this process, GlyRS ensures the accurate incorporation of glycine during translation, making it essential for proper protein production. Many different mutations have been found in CMT2D patients, and how mutations in GARS1 cause CMT2D remains unclear. However, mutant glycyl-tRNA synthetase (GlyRS) is thought to interfere with transmembrane receptors, causing motor disease, and that mutations in the gene could disrupt the ability of GlyRS to interact with its cognate RNA, disrupting protein production. The GARS1 mutations present in CMT2D cause a deficient amount of glycyl-tRNA in cells, preventing the elongation phase of protein synthesis. Elongation is a key step in protein production, so when a deficiency of glycyl-tRNA exists, protein synthesis is unable to continue at glycine sites. GARS1 mutations also stall initiation of translation due to a stress response that is induced by glycine addition failure. By stalling elongation and initiation of translation, CMT2D mutations in GARS1 cause translational repression, meaning that overall translation is inhibited. GARS1-associated axonal neuropathy is a progressive condition that deteriorates over time.
April 14: Ordinance on army promotions regulates the number of canteen workers and laundresses attached to an army corps; they must be married to an active soldier in that corps, with marriages or retention of widows subject to the regulated number (wives of master craftsmen in the general staff are excluded). April 21: For determining beverage outlet taxes in a municipality, proxies represent women. April 28: Law amending the Criminal Procedure Code and Penal Code, including provisions on indecent assault, rape, and abortion. 1833
=== 4. Alveolar bone (alveolar process) === The alveolar bone forms part of the maxilla and mandible and provides the osseous support for the teeth by forming their sockets. Its structure and density are maintained by functional forces transmitted through the periodontal ligament. In periodontitis, inflammatory mediators released during the host immune response stimulate osteoclastic activity, leading to alveolar bone resorption. This irreversible loss of supporting bone is a hallmark of clinical attachment loss and represents the most significant structural consequence of periodontal disease.
=== Bones, joints, frailty, posture and in people at risk === Strength training also provides functional benefits. Stronger muscles improve posture, provide better support for joints, and reduce the risk of injury from everyday activities. Progressive resistance training may improve function, quality of life and reduce pain in people at risk of fracture, with rare adverse effects. Weight-bearing exercise also helps to prevent osteoporosis and to improve bone strength in those with osteoporosis. For many people in rehabilitation or with an acquired disability, such as following stroke or orthopaedic surgery, strength training for weak muscles is a key factor to optimise recovery. Consistent exercise can actually strengthen bones and prevent them from getting frail with age.
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 best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.