Psychedelic-inspired drug discovery using an engineered biosensor.

Ligands can induce G protein-coupled receptors (GPCRs) to adopt a myriad of conformations, many of which play critical roles in determining the activation of specific signaling cascades associated with distinct functional and behavioral consequences. For example, the 5-hydroxytryptamine 2A receptor (5-HT2AR) is the target of classic hallucinogens, atypical antipsychotics, and psychoplastogens. However, currently available methods are inadequate for directly assessing 5-HT2AR conformation both in vitro and in vivo. Here, we developed psychLight, a genetically encoded fluorescent sensor based on the 5-HT2AR structure. PsychLight detects behaviorally relevant serotonin release and correctly predicts the hallucinogenic behavioral effects of structurally similar 5-HT2AR ligands. We further used psychLight to identify a non-hallucinogenic psychedelic analog, which produced rapid-onset and long-lasting antidepressant-like effects after a single administration. The advent of psychLight will enable in vivo detection of serotonin dynamics, early identification of designer drugs of abuse, and the development of 5-HT2AR-dependent non-hallucinogenic therapeutics.

An excitatory ventromedial hypothalamus to paraventricular thalamus circuit that suppresses food intake.

It is well recognized that ventromedial hypothalamus (VMH) serves as a satiety center in the brain. However, the feeding circuit for the VMH regulation of food intake remains to be defined. Here, we combine fiber photometry, chemo/optogenetics, virus-assisted retrograde tracing, ChR2-assisted circuit mapping and behavioral assays to show that selective activation of VMH neurons expressing steroidogenic factor 1 (SF1) rapidly inhibits food intake, VMH SF1 neurons project dense fibers to the paraventricular thalamus (PVT), selective chemo/optogenetic stimulation of the PVT-projecting SF1 neurons or their projections to the PVT inhibits food intake, and chemical genetic inactivation of PVT neurons diminishes SF1 neural inhibition of feeding. We also find that activation of SF1 neurons or their projections to the PVT elicits a flavor aversive effect, and selective optogenetic stimulation of ChR2-expressing SF1 projections to the PVT elicits direct excitatory postsynaptic currents. Together, our data reveal a neural circuit from VMH to PVT that inhibits food intake.

Compound 21, a two-edged sword with both DREADD-selective and off-target outcomes in rats.

Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) represent a technical revolution in integrative neuroscience. However, the first used ligands exhibited dose-dependent selectivity for their molecular target, leading to potential unspecific effects. Compound 21 (C21) was recently proposed as an alternative, but in vivo characterization of its properties is not sufficient yet. Here, we evaluated its potency to selectively modulate the activity of nigral dopaminergic (DA) neurons through the canonical DREADD receptor hM4Di using TH-Cre rats. In males, 1 mg.kg-1 of C21 strongly increased nigral neurons activity in control animals, indicative of a significant off-target effect. Reducing the dose to 0.5 mg.kg-1 circumvented this unspecific effect, while activated the inhibitory DREADDs and selectively reduced nigral neurons firing. In females, 0.5 mg.kg-1 of C21 induced a transient and residual off-target effect that may mitigated the inhibitory DREADDs-mediated effect. This study raises up the necessity to test selectivity and efficacy of chosen ligands for each new experimental condition.

Hallucinogen-Like Action of the Novel Designer Drug 25I-NBOMe and Its Effect on Cortical Neurotransmitters in Rats.

NBOMes are N-benzylmethoxy derivatives of the 2C family hallucinogens. 4-Iodo-2,5-dimethoxy-N-(2-methoxybenzyl)phenethylamine (25I-NBOMe) is one of the commonly used illicit drugs. It exhibits high binding affinity for 5-HT2A/C and 5-HT1A serotonin receptors. Activation of 5-HT2A receptor induces head-twitch response (HTR) in rodents, a behavioral marker of hallucinogen effect in humans. There is not much data on neurochemical properties of NBOMes. Therefore, we aimed to investigate the effect of 25I-NBOMe on extracellular level of dopamine (DA), serotonin (5-HT), and glutamate (GLU) in the rat frontal cortex, tissue contents of monoamines, and hallucinogenic activity in rats. The extracellular levels of DA, 5-HT, and GLU were studied using microdialysis in freely moving animals. The tissue contents of DA, 5-HT and their metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were determined in the rat frontal cortex. We also tested a drug-elicited HTR. 25I-NBOMe at doses 1, 3, and 10 mg/kg (sc) increased extracellular DA, 5-HT, and GLU levels, enhanced tissue content of 5-HT and 5-HIAA, but did not affect tissue level of DA and its metabolites. The compound exhibited an inverted U-shaped dose-response curve with respect to the effect on extracellular DA and 5-HT levels, but a U-shaped dose-response curve was observed for its effect on GLU release and HTR. The data from our study suggest that hallucinogenic activity of 25I-NBOMe seems to be related with the increase in extracellular GLU level-mediated via cortical 5-HT2A receptors. The influence of 25I-NBOMe on 5-HT2C and 5-HT1A receptors may modulate its effect on neurotransmitters and HTR.

DREADD-based synthetic control of chondrocyte calcium signaling in vitro.

Calcium is a critical second messenger involved in chondrocyte mechanotransduction. Several distinct calcium signaling mechanisms implicated in chondrocyte mechanotransduction have been identified using mechanical perturbations or soluble signaling factors. However, these commonly used stimuli can lack specificity in the mechanisms by which they initiate calcium signaling. Synthetic tools allowing for more precise and selective regulation of calcium signaling, such as the engineered G-protein-coupled receptors known as DREADDs (Designer Receptors Exclusively Activated by Designer Drugs), may better assist in isolating the roles of intracellular calcium ([Ca2+ ]i ) and cell activation in chondrocyte biology. One DREADD, hM3Dq, is solely activated by clozapine N-oxide (CNO) and regulates calcium activation through the Gq -PLCß-IP3 -ER pathway. Here, hM3Dq-transfected ATDC5 cells were treated with CNO (100 nM-1 µM) to establish the feasibility of using Gq -DREADDs to drive [Ca2+ ]i activation in chondrocyte-like cells. CNO administration resulted in a coordinated, dose-dependent, and transient calcium response in hM3Dq-transfected cells that resulted primarily from calcium release from the ER. Following activation via CNO administration, hM3Dq-ATDC5 cells exhibited refractory behavior and required a 4-h wash-out period to recover hM3Dq-mediated signaling. However, hM3Dq inactivation did not inhibit alternative calcium activation mechanisms in ATDC5 cells (via GSK101 or hypo-osmotic shock), nor did CNO-driven calcium signaling negatively impact ATDC5 cell health. This study established the successful use of hM3Dq for the safe, targeted, and well-controlled activation of calcium signaling in ATDC5 cells and its use as a potential tool for assessing clinically significant questions regarding calcium signaling in chondrocyte biology, cartilage pathology, and cartilage tissue engineering. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1518-1529, 2019.

Fentanyl-related designer drugs W-18 and W-15 lack appreciable opioid activity in vitro and in vivo.

W-18 (4-chloro-N-[1-[2-(4-nitrophenyl)ethyl]-2-piperidinylidene]-benzenesulfonamide) and W-15 (4-chloro-N-[1-(2-phenylethyl)-2-piperidinylidene]-benzenesulfonamide) represent two emerging drugs of abuse chemically related to the potent opioid agonist fentanyl (N-(1-(2-phenylethyl)-4-piperidinyl)-N-phenylpropanamide). Here, we describe the comprehensive pharmacological profiles of W-18 and W-15, as examination of their structural features predicted that they might lack opioid activity. We found W-18 and W-15 to be without detectible activity at µ, δ, κ, and nociception opioid receptors in a variety of assays. We also tested W-18 and W-15 for activity as allosteric modulators at opioid receptors and found them devoid of significant positive or negative allosteric modulatory activity. Comprehensive profiling at essentially all the druggable GPCRs in the human genome using the PRESTO-Tango platform revealed no significant activity. Weak activity at the sigma receptors and the peripheral benzodiazepine receptor was found for W-18 (Ki = 271 nM). W-18 showed no activity in either the radiant heat tail-flick or the writhing assays and also did not induce classical opioid behaviors. W-18 is extensively metabolized, but its metabolites also lack opioid activity. Thus, although W-18 and W-15 have been suggested to be potent opioid agonists, our results reveal no significant activity at these or other known targets for psychoactive drugs.

Studying brain-regulation of immunity with optogenetics and chemogenetics; A new experimental platform.

The interactions between the brain and the immune system are bidirectional. Nevertheless, we have far greater understanding of how the immune system affects the brain than how the brain affects immunity. New technological developments such as optogenetics and chemogenetics (using DREADDs; Designer Receptors Exclusively Activated by Designer Drugs) can bridge this gap in our understanding, as they enable an unprecedented mechanistic and systemic analysis of the communication between the brain and the immune system. In this review, we discuss new experimental approaches for revealing neuronal circuits that can participate in regulation of immunity. In addition, we discuss methods, specifically optogenetics and chemogenetics, that enable targeted neuronal manipulation to reveal how different brain regions affect immunity. We describe how these techniques can be used as an experimental platform to address fundamental questions in psychoneuroimmunology and to understand how neuronal circuits associate with different psychological states can affect physiology.

Focus on cannabinoids and synthetic cannabinoids.

The recent emergence of a multitude of synthetic cannabinoids (SCs) has generated a wealth of new information, suggesting the usefulness of state-of-the-art on lato sensu cannabinoids. By modulating a plurality of neurotransmission pathways, the endocannabinoid system is involved in many physiological processes that are increasingly explored. SCs desired and adverse effects are considered to be more intense than those observed with cannabis smoking, which is partly explained by the full agonist activity and higher affinity for cannabinoid receptors. Neurological and cardiovascular side effects observed after cannabinoid poisoning generally respond to conventional supportive care, but severe outcomes may occur in a minority of cases, mainly observed with SCs. The likelihood of severe abuse and addiction produced by SCs are of concern for the scientific community also interested in the potential therapeutic value of cannabinoids.

Pharmacology of Indole and Indazole Synthetic Cannabinoid Designer Drugs AB-FUBINACA, ADB-FUBINACA, AB-PINACA, ADB-PINACA, 5F-AB-PINACA, 5F-ADB-PINACA, ADBICA, and 5F-ADBICA.

Synthetic cannabinoid (SC) designer drugs based on indole and indazole scaffolds and featuring l-valinamide or l-tert-leucinamide side chains are encountered with increasing frequency by forensic researchers and law enforcement agencies and are associated with serious adverse health effects. However, many of these novel SCs are unprecedented in the scientific literature at the time of their discovery, and little is known of their pharmacology. Here, we report the synthesis and pharmacological characterization of AB-FUBINACA, ADB-FUBINACA, AB-PINACA, ADB-PINACA, 5F-AB-PINACA, 5F-ADB-PINACA, ADBICA, 5F-ADBICA, and several analogues. All synthesized SCs acted as high potency agonists of CB1 (EC50 = 0.24-21 nM) and CB2 (EC50 = 0.88-15 nM) receptors in a fluorometric assay of membrane potential, with 5F-ADB-PINACA showing the greatest potency at CB1 receptors. The cannabimimetic activities of AB-FUBINACA and AB-PINACA in vivo were evaluated in rats using biotelemetry. AB-FUBINACA and AB-PINACA dose-dependently induced hypothermia and bradycardia at doses of 0.3-3 mg/kg, and hypothermia was reversed by pretreatment with a CB1 (but not CB2) antagonist, indicating that these SCs are cannabimimetic in vivo, consistent with anecdotal reports of psychoactivity in humans.

Synthetic androgens as designer supplements.

Anabolic androgenic steroids (AAS) are some of the most common performance enhancing drugs (PED) among society. Despite the broad spectrum of adverse effects and legal consequences, AAS are illicitly marketed and distributed in many countries. To circumvent existing laws, the chemical structure of AAS is modified and these designer steroids are sold as nutritional supplements mainly over the Internet. Several side effects are linked with AAS abuse. Only little is known about the pharmacological effects and metabolism of unapproved steroids due to the absence of clinical studies. The large number of designer steroid findings in dietary supplements and the detection of new compounds combined with legal loopholes for their distribution in many countries show that stricter regulations and better information policy are needed.

Effects of bioisosteric fluorine in synthetic cannabinoid designer drugs JWH-018, AM-2201, UR-144, XLR-11, PB-22, 5F-PB-22, APICA, and STS-135.

Synthetic cannabinoid (SC) designer drugs featuring bioisosteric fluorine substitution are identified by forensic chemists and toxicologists with increasing frequency. Although terminal fluorination of N-pentyl indole SCs is sometimes known to improve cannabinoid type 1 (CB1) receptor binding affinity, little is known of the effects of fluorination on functional activity of SCs. This study explores the in vitro functional activities of SC designer drugs JWH-018, UR-144, PB-22, and APICA, and their respective terminally fluorinated analogues AM-2201, XLR-11, 5F-PB-22, and STS-135 at human CB1 and CB2 receptors using a FLIPR membrane potential assay. All compounds demonstrated agonist activity at CB1 (EC50 = 2.8-1959 nM) and CB2 (EC50 = 6.5-206 nM) receptors, with the fluorinated analogues generally showing increased CB1 receptor potency (∼2-5 times). Additionally, the cannabimimetic activities and relative potencies of JWH-018, AM-2201, UR-144, XLR-11, PB-22, 5F-PB-22, APICA, and STS-135 in vivo were evaluated in rats using biotelemetry. All SCs dose-dependently induced hypothermia and reduced heart rate at doses of 0.3-10 mg/kg. There was no consistent trend for increased potency of fluorinated SCs over the corresponding des-fluoro SCs in vivo. Based on magnitude and duration of hypothermia, the SCs were ranked for potency (PB-22 > 5F-PB-22 = JWH-018 > AM-2201 > APICA = STS-135 = XLR-11 > UR-144).

Behavioral pharmacology of designer cathinones: a review of the preclinical literature.

"Bath salts" is one street name for a family of synthetic cathinones that display pharmacological effects resembling cocaine and commonly abused amphetamines. Despite extensive legislation aimed at the criminalization of bath salts, several designer cathinones are gaining a foothold in the illicit drug scene; for example, in the United Kingdom, mephedrone (4-methylmethcathinone, MEPH) is highly popular among drug abusers whereas, in the United States, MDPV (methylenedioxypyrovalerone) and methylone are highly prevalent. To date, knowledge about the hazards of designer cathinones is based mostly on hospital reports and anecdotal evidence derived from online surveys. Despite the paucity of preclinical studies directed toward designer cathinones, a number of invaluable findings arising from those studies are enabling scientists to develop their neuropharmacological profiles. Despite their commonalities in chemical structures, synthetic cathinones possess distinct neuropharmacological profiles and produce different behavioral effects, including unique effects on locomotor activity, learning, anxiety, thermoregulation, and abuse liability. The present review will discuss the behavioral effects of MEPH, MDPV, and methylone and compare those effects to established psychostimulant drugs. The rise in the use of designer cathinones in the United States and abroad justifies further investigations into these compounds, both for a greater understanding of the danger that "bath salts" pose to the public, and to provide insight into replacement cathinones as they emerge onto the market.

"Herbal incense": designer drug blends as cannabimimetics and their assessment by drug discrimination and other in vivo bioassays.

Recently, synthetic cannabinoids originally designed for testing in the laboratory only have found use recreationally in designer herbal blends, originally called "Spice". The myriad of compounds found are for the most part potent full agonists of the cannabinoid receptor 1, producing effects similar to tetrahydrocannabinol (THC) and marijuana. Drug discrimination of these compounds offers a specific behavioral test that can help determine whether these new synthetic compounds share a similar "subjective high" with the effects of marijuana/THC. By utilization of drug discrimination and other behavioral techniques, a better understanding of these new "designer" cannabinoids may be reached to assist in treating both the acute and chronic effects of these drugs. The paper provides a brief exposé of modern cannabinoid research as a backdrop to the recreational use of designer herbal blend cannabimimetics.

Natural product 'legal highs'.

The last five years have seen a dramatic increase in the global popularity of 'Legal Highs', often referred to as Novel Psychoactive Substances (NPS). These materials are single chemicals, plant or fungal materials or their extracts, which may be purchased and possessed without legal restriction in certain countries. The single chemical entity drugs are often closely structurally related to existing controlled drugs of abuse from, for example, the amphetamine (phenethylamine), cannabinoid-mimetic or tryptamine classes, whereas the natural products are from plant or fungal materials that have a long history of pharmacognosy. These natural product legal highs are by their very nature highly chemically complex, and in the clear majority of cases, chemical studies were conducted some considerable time ago. Their pharmacology and toxicology generally focuses on the major active principles with few studies detailing the potentially highly complicated and multiple effects of their extracts. This complexity, coupled with the inherent natural product variability of plant and fungal species, adds a further dimension to the potential harms associated with natural product legal high use. This review encompasses the most popular current legal highs and describes their basic chemistry, usage and preparation, pharmacology, toxicology and discusses the issues surrounding the complexity of these materials, and how this can impact on the evaluation of their harms.

Spice drugs are more than harmless herbal blends: a review of the pharmacology and toxicology of synthetic cannabinoids.

"K2" and "Spice" drugs (collectively hereafter referred to as Spice) represent a relatively new class of designer drugs that have recently emerged as popular alternatives to marijuana, otherwise characterized as "legal highs". These drugs are readily available on the Internet and sold in many head shops and convenience stores under the disguise of innocuous products like herbal blends, incense, or air fresheners. Although package labels indicate "not for human consumption", the number of intoxicated people presenting to emergency departments is dramatically increasing. The lack of validated and standardized human testing procedures and an endless supply of potential drugs of abuse are primary reasons why researchers find it difficult to fully characterize clinical consequences associated with Spice. While the exact chemical composition and toxicology of Spice remains to be determined, there is mounting evidence identifying several synthetic cannabinoids as causative agents responsible for psychoactive and adverse physical effects. This review provides updates of the legal status of common synthetic cannabinoids detected in Spice and analytical procedures used to test Spice products and human specimens collected under a variety of clinical circumstances. The pharmacological and toxicological consequences of synthetic cannabinoid abuse are also reviewed to provide a future perspective on potential short- and long-term implications.

Endocrine characterization of the designer steroid methyl-1-testosterone: investigations on tissue-specific anabolic-androgenic potency, side effects, and metabolism.

Various products containing rarely characterized anabolic steroids are nowadays marketed as dietary supplements. Herein, the designer steroid methyl-1-testosterone (M1T) (17ß-hydroxy-17α-methyl-5α-androst-1-en-3-one) was identified, and its biological activity, potential adverse effects, and metabolism were investigated. The affinity of M1T toward the androgen receptor (AR) was tested in vitro using a yeast AR transactivation assay. Its tissue-specific androgenic and anabolic potency and potential adverse effects were studied in a Hershberger assay (sc or oral), and tissue weights and selected molecular markers were investigated. Determination of M1T and its metabolites was performed by gas chromatography mass spectrometry. In the yeast AR transactivation assay, M1T was characterized as potent androgen. In rats, M1T dose-dependently stimulated prostate and levator ani muscle weight after sc administration. Oral administration had no effect but stimulated proliferation in the prostate and modulated IGF-I and AR expression in the gastrocnemius muscle in a dose-dependent manner. Analysis of tyrosine aminotransferase expression provided evidence for a strong activity of M1T in the liver (much higher after oral administration). In rat urine, 17α-methyl-5α-androstane-3α,17ß-diol, M1T, and a hydroxylated metabolite were identified. In humans, M1T was confirmed in urine in addition to its main metabolites 17α-methyl-5α-androst-1-ene-3α,17ß-diol and 17α-methyl-5α-androstane-3α,17ß-diol. Additionally, the corresponding 17-epimers as well as 17ß-hydroxymethyl-17α-methyl-18-nor-5α-androsta-1,13-dien-3-one and its 17-epimer were detected, and their elimination kinetics was monitored. It was demonstrated that M1T is a potent androgenic and anabolic steroid after oral and sc administration. Obviously, this substance shows no selective AR modulator characteristics and might exhibit liver toxicity, especially after oral administration.

Marijuana-based drugs: innovative therapeutics or designer drugs of abuse?

The principal psychoactive component of marijuana, Δ(9)-tetrahydrocannabinol (THC), activates CB1 cannabinoid receptors (CB1Rs). Unfortunately, pharmacological research into the design of effective THC analogs has been hampered by psychiatric side effects. THC-based drug design of a less academic nature, however, has led to the marketing of "synthetic marijuana," labeled as K2 or "Spice," among other terms, which elicits psychotropic actions via CB1R activation. Because of structural dissimilarity to THC, the active ingredients of K2/Spice preparations are widely unregulated. The K2/Spice "phenomenon" provides a context for considering whether marijuana-based drugs will truly provide innovative therapeutics or merely perpetuate drug abuse.

Chemistry, pharmacology, and metabolism of emerging drugs of abuse.

In recent years, besides the classic designer drugs of the amphetamine type, a series of new drug classes appeared on the illicit drugs market. The chemistry, pharmacology, toxicology, metabolism, and toxicokinetics is discussed of 2,5-dimethoxy amphetamines, 2,5-dimethoxy phenethylamines, beta-keto-amphetamines, phencyclidine derivatives as well as of herbal drugs, ie, Kratom. They have gained popularity and notoriety as rave drugs. The metabolic pathways, the involvement of cytochrome P450 isoenzymes in the main pathways, and their roles in hepatic clearance are also summarized.

Designer steroids.

Anabolic steroids have been studied for over 50 years and during that time numerous compounds with a variety of functional groups have been produced and many have been published. Of these only a small number have been introduced to the pharmaceutical market. WADA has continued the work begun by the IOC banning the use of these agents within sport as performance enhancing substances. Athletes, however, continue to use these anabolic steroids but tighter testing and the introduction of unannounced sample collection has made this form of cheating harder.In order to try to evade detection, athletes who continue to dope are having to resort to the use of a far more dangerous form of drug - the designer steroid. These steroids are manufactured to closely resemble existing known compounds, but with sufficient chemical diversity to ensure that their detection by the WADA accredited laboratories is more difficult. A worrying feature of the use of these compounds is that no data is available to evaluate either the efficacy or the safety of these substances. Many such drugs are now being made in clandestine ways (as demonstrated by the recent BALCO case) and then passed on to athletes who become the guinea pigs determining the potential of the substances as doping agents.Methods for the detection of these new compounds are being developed using emerging techniques such as gas chromatography or liquid chromatography attached to a variety of mass spectrometry instruments. This technology as well as vigilance by laboratories and enforcement agencies can all help in early detection of designer steroids being used for doping.

Consumo de drogas de síntesis en jóvenes españoles / No disponible

Las drogas de síntesis se obtienen por elaboración química, fundamentalmente en laboratoriosclandestinos, sin ningún control sanitario. Generalmente se trata de compuestosanfetamínicos a los que se suelen añadir algunos componentes de efectos alucinógenos.Provocan clara dependencia psíquica. Es frecuente el policonsumo con otras drogas. Entrelos efectos físicos que aparecen, en caso de intoxicación aguda por drogas de síntesis, se encuentrael síndrome hipertérmico, que en los casos más graves puede conducir a la muerte

Synthetic drugs are obtained by chemical elaboration, fundamentally in clandestine laboratories,with no sanitary control. Generally, they are amphetamine compounds to whichusually they add some components of hallucinogenic effects. They cause clear psychic dependency.Polyconsumption with other drugs is frequent. One of the physical effects thatcan appear in case of acute intoxication by synthetic drugs is the hyperthermic syndrome,that in the most serious cases can lead to death