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Journal of Analytical Toxicology Mar 2024A safe and productive workplace requires a sober workforce, free from substances that impair judgment and concentration. Although drug monitoring programs already exist,...
A safe and productive workplace requires a sober workforce, free from substances that impair judgment and concentration. Although drug monitoring programs already exist, the scope and loopholes of standard workplace testing panels are well known, allowing other substances to remain a source of risk. Therefore, a high-throughput urine screening method for psilocin, mitragynine, phencyclidine, ketamine, norketamine and dehydronorketamine was developed and validated in conjunction with a urine and blood confirmation method. There are analytical challenges to overcome with psilocin and mitragynine, particularly when it comes to drug stability and unambiguous identification in authentic specimens. Screening and confirmation methods were validated according to the American National Standards Institute/Academy Standards Board (ANSI/ASB) Standard 036, Standard Practices for Method Validation in Forensic Toxicology. An automated liquid handling system equipped with dispersive pipette extraction tips was utilized for preparing screening samples, whereas an offline solid-phase extraction method was used for confirmation sample preparation. Both methods utilized liquid chromatography-tandem mass spectrometry to achieve limits of detection between 1-5 ng/mL for the screening method and 1 ng/mL for the confirmation method. Automation allows for faster throughput and enhanced quality assurance, which improves turnaround time. Compared to previous in-house methods, specimen volumes were substantially decreased for both blood and urine, which is an advantage when volume is limited. This screening technique is well suited for evaluating large numbers of specimens from those employed in safety-sensitive workforce positions. This method can be utilized by workplace drug testing, human performance and postmortem laboratories seeking robust qualitative screening and confirmation methods for analytes that have traditionally been challenging to routinely analyze.
Topics: Humans; Ketamine; Phencyclidine; Tandem Mass Spectrometry; Chromatography, Liquid; Psilocybin; Secologanin Tryptamine Alkaloids
PubMed: 38287693
DOI: 10.1093/jat/bkae002 -
Science Advances Jan 2024Metabotropic glutamate receptor 2 (mGlu) attracts particular attention as a possible target for a new class of antipsychotics. However, the signaling pathways...
Metabotropic glutamate receptor 2 (mGlu) attracts particular attention as a possible target for a new class of antipsychotics. However, the signaling pathways transducing the effects of mGlu in the brain remain poorly characterized. Here, we addressed this issue by identifying native mGlu interactome in mouse prefrontal cortex. Nanobody-based affinity purification and mass spectrometry identified 149 candidate mGlu partners, including the neurotrophin receptor TrkB. The later interaction was confirmed both in cultured cells and prefrontal cortex. mGlu activation triggers phosphorylation of TrkB on Tyr in primary cortical neurons and prefrontal cortex. Reciprocally, TrkB stimulation enhances mGlu-operated G protein activation. Furthermore, TrkB inhibition prevents the rescue of behavioral deficits by glutamatergic antipsychotics in phencyclidine-treated mice. Collectively, these results reveal a cross-talk between TrkB and mGlu, which is key to the behavioral response to glutamatergic antipsychotics.
Topics: Mice; Animals; Antipsychotic Agents; Receptor, trkB; Prefrontal Cortex; Cells, Cultured; Neurons
PubMed: 38277461
DOI: 10.1126/sciadv.adg1679 -
The Journal of Pharmacology and... Jun 2024Abuse of novel arylcyclohexylamines (ACX) poses risks for toxicities, including adverse neurocognitive effects. In vivo effects of ring-substituted analogs of...
Abuse of novel arylcyclohexylamines (ACX) poses risks for toxicities, including adverse neurocognitive effects. In vivo effects of ring-substituted analogs of phencyclidine (PCP), eticyclidine (PCE), and ketamine are understudied. Adult male National Institutes of Health Swiss mice were used to assess locomotor effects of PCP and its 3-OH, 3-MeO, 3-Cl, and 4-MeO analogs, PCE and its 3-OH and 3-MeO analogs, and ketamine and its deschloro and 2F-deschloro analogs, in comparison with those of methamphetamine (METH), 3,4-methylenedioxymethamphetamine (MDMA), and two benzofuran analogs of MDMA. PCP-like interoceptive effects for all of these ACXs were determined using a food-reinforced drug discrimination procedure in adult male Sprague Dawley rats. A novel operant assay of rule-governed behavior incorporating aspects of attentional set-shifting was used to profile psychosis-like neurocognitive effects of PCP and 3-Cl-PCP in rats, in comparison with cocaine and morphine. PCP-like ACXs were more effective locomotor stimulants than the amphetamines, PCE-like ACXs were as effective as the amphetamines, and ketamine-like ACXs were less effective than the amphetamines. Addition of -Cl, -OH, or -OMe at the 3-position on the aromatic ring did not impact locomotor effectiveness, but addition of -OMe at the 4-position reduced locomotor effectiveness. Lethal effects were induced by drugs with -OH at the 3-position or -OMe at the 3- or 4-position. All novel ACXs substituted at least partially for PCP, and PCP and 3-Cl-PCP elicited dose-dependent psychosis-like neurocognitive deficits in the rule-governed behavior task not observed with cocaine or morphine. Novel ACXs exhibit substantial abuse liability and toxicities not necessarily observed with their parent drugs. SIGNIFICANCE STATEMENT: Novel arylcyclohexylamine analogs of PCP, PCE, and ketamine are appearing on the illicit market, and abuse of these drugs poses risks for toxicities, including adverse neurocognitive effects. These studies demonstrate that the novel ACXs exhibit PCP-like abuse liability in the drug discrimination assay, elicit varied locomotor stimulant and lethal effects in mice, and induce psychosis-like neurocognitive effects in rats.
Topics: Animals; Male; Mice; Phencyclidine; Rats, Sprague-Dawley; Rats; Psychoses, Substance-Induced; Cyclohexylamines; Motor Activity; Cognition; Conditioning, Operant; Locomotion; Illicit Drugs; Ketamine; Substance-Related Disorders; Phencyclidine Abuse
PubMed: 38272671
DOI: 10.1124/jpet.123.001942 -
Research Square Dec 2023Cognitive deficits are a long-lasting consequence of drug use, yet the convergent mechanism by which classes of drugs with different pharmacological properties cause...
Cognitive deficits are a long-lasting consequence of drug use, yet the convergent mechanism by which classes of drugs with different pharmacological properties cause similar deficits is unclear. We find that both phencyclidine and methamphetamine, despite differing in their targets in the brain, cause the same glutamatergic neurons in the medial prefrontal cortex to gain a GABAergic phenotype and decrease their expression of the vesicular glutamate transporter. Suppressing the drug-induced gain of GABA with RNA-interference prevents the appearance of memory deficits. Stimulation of dopaminergic neurons in the ventral tegmental area is necessary and sufficient to produce this gain of GABA. Drug-induced prefrontal hyperactivity drives this change in transmitter identity. Returning prefrontal activity to baseline, chemogenetically or with clozapine, reverses the change in transmitter phenotype and rescues the associated memory deficits. The results reveal a shared and reversible mechanism that regulates the appearance of cognitive deficits upon exposure to different drugs.
PubMed: 38168375
DOI: 10.21203/rs.3.rs-3689243/v1 -
BioRxiv : the Preprint Server For... Dec 2023Genetic analyses of Schizophrenia (SCZ) patients have identified thousands of risk factors. In silico protein-protein interaction (PPI) network analysis has provided...
Genetic analyses of Schizophrenia (SCZ) patients have identified thousands of risk factors. In silico protein-protein interaction (PPI) network analysis has provided strong evidence that disrupted PPI networks underlie SCZ pathogenesis. In this study, we performed PPI analysis of several SCZ risk factors in the rodent brain. Using endogenous antibody immunoprecipitations coupled to mass spectrometry (MS) analysis, we constructed a SCZ network comprising 1612 unique PPI with a 5% FDR. Over 90% of the PPI were novel, reflecting the lack of previous PPI MS studies in brain tissue. Our SCZ PPI network was enriched with known SCZ risk factors, which supports the hypothesis that an accumulation of disturbances in selected PPI networks underlies SCZ. We used Stable Isotope Labeling in Mammals (SILAM) to quantitate phencyclidine (PCP) perturbations in the SCZ network and found that PCP weakened most PPI but also led to some enhanced or new PPI. These findings demonstrate that quantitating PPI in perturbed biological states can reveal alterations to network biology.
PubMed: 38168169
DOI: 10.1101/2023.12.12.571320 -
Biological Psychiatry Dec 2023Polymorphisms in the gene encoding for metabotropic glutamate receptor 3 (mGlu) are associated with an increased likelihood of schizophrenia diagnosis and can predict...
BACKGROUND
Polymorphisms in the gene encoding for metabotropic glutamate receptor 3 (mGlu) are associated with an increased likelihood of schizophrenia diagnosis and can predict improvements in negative symptoms following treatment with antipsychotics. However, the mechanisms by which mGlu can regulate brain circuits involved in schizophrenia pathophysiology are not clear.
METHODS
We employed selective pharmacological tools and a variety of approaches including whole-cell patch-clamp electrophysiology, slice optogenetics, and fiber photometry to investigate the effects of mGlu activation on phencyclidine (PCP)-induced impairments in thalamo-accumbal transmission and sociability deficits. A chemogenetic approach was used to evaluate the role of thalamo-accumbal transmission in PCP-induced sociability deficits.
RESULTS
We first established that PCP treatment augmented excitatory transmission onto dopamine D receptor-expressing medium spiny neurons (D1-MSNs) in the nucleus accumbens (NAc) and induced sociability deficits. Our studies revealed a selective increase in glutamatergic synaptic transmission from thalamic afferents to D1-MSNs in the NAc shell. Chemogenetic silencing of thalamo-accumbal inputs rescued PCP-induced sociability deficits. Pharmacological activation of mGlu normalized PCP-induced impairments in thalamo-accumbal transmission and sociability deficits. Mechanistic studies revealed that mGlu activation induced robust long-term depression at synapses from the thalamic projections onto D1-MSNs in the NAc shell.
CONCLUSIONS
These data demonstrate that activation of mGlu decreases thalamo-accumbal transmission and thereby rescues sociability deficits in mouse modeling schizophrenia-like symptoms. These findings provide novel insights into the NAc-specific mechanisms and suggest that agents modulating glutamatergic signaling in the NAc may provide a promising approach for treating negative symptoms in schizophrenia.
PubMed: 38061467
DOI: 10.1016/j.biopsych.2023.11.023 -
Neuropsychopharmacology : Official... Mar 2024One of the critical unmet medical needs in schizophrenia is the treatment for cognitive deficits. However, the neural circuit mechanisms of them remain unresolved.... (Comparative Study)
Comparative Study
Activation of prefrontal parvalbumin interneurons ameliorates working memory deficit even under clinically comparable antipsychotic treatment in a mouse model of schizophrenia.
One of the critical unmet medical needs in schizophrenia is the treatment for cognitive deficits. However, the neural circuit mechanisms of them remain unresolved. Previous studies utilizing animal models of schizophrenia did not consider the fact that patients with schizophrenia generally cannot discontinue antipsychotic medication due to the high risk of relapse. Here, we used multi-dimensional approaches, including histological analysis of the prelimbic cortex (PL), LC-MS/MS-based in vivo dopamine D2 receptor occupancy analysis for antipsychotics, in vivo calcium imaging, and behavioral analyses of mice using chemogenetics to investigate neural mechanisms and potential therapeutic strategies for working memory deficit in a chronic phencyclidine (PCP) mouse model of schizophrenia. Chronic PCP administration led to alterations in excitatory and inhibitory synapses, specifically in dendritic spines of pyramidal neurons, vesicular glutamate transporter 1 (VGLUT1) positive terminals, and parvalbumin (PV) positive GABAergic interneurons located in layer 2-3 of the PL. Continuous administration of olanzapine, which achieved a sustained therapeutic window of dopamine D2 receptor occupancy (60-80%) in the striatum, did not ameliorate these synaptic abnormalities and working memory deficit in the chronic PCP-treated mice. We demonstrated that chemogenetic activation of PV neurons in the PL, as confirmed by in vivo calcium imaging, ameliorated working memory deficit in this model even under clinically comparable olanzapine treatment which by itself inhibited only PCP-induced psychomotor hyperactivity. Our study suggests that targeting prefrontal PV neurons could be a promising therapeutic intervention for cognitive deficits in schizophrenia in combination with antipsychotic medication.
Topics: Animals; Humans; Mice; Antipsychotic Agents; Calcium; Chromatography, Liquid; Disease Models, Animal; Interneurons; Memory Disorders; Olanzapine; Parvalbumins; Phencyclidine; Prefrontal Cortex; Receptors, Dopamine D2; Schizophrenia; Tandem Mass Spectrometry
PubMed: 38049583
DOI: 10.1038/s41386-023-01769-z -
Analytical Chemistry Dec 2023The market for illicit drugs has been reshaped by the emergence of more than 1100 new psychoactive substances (NPS) over the past decade, posing a major challenge to the...
The market for illicit drugs has been reshaped by the emergence of more than 1100 new psychoactive substances (NPS) over the past decade, posing a major challenge to the forensic and toxicological laboratories tasked with detecting and identifying them. Tandem mass spectrometry (MS/MS) is the primary method used to screen for NPS within seized materials or biological samples. The most contemporary workflows necessitate labor-intensive and expensive MS/MS reference standards, which may not be available for recently emerged NPS on the illicit market. Here, we present NPS-MS, a deep learning method capable of accurately predicting the MS/MS spectra of known and hypothesized NPS from their chemical structures alone. NPS-MS is trained by transfer learning from a generic MS/MS prediction model on a large data set of MS/MS spectra. We show that this approach enables a more accurate identification of NPS from experimentally acquired MS/MS spectra than any existing method. We demonstrate the application of NPS-MS to identify a novel derivative of phencyclidine (PCP) within an unknown powder seized in Denmark without the use of any reference standards. We anticipate that NPS-MS will allow forensic laboratories to identify more rapidly both known and newly emerging NPS. NPS-MS is available as a web server at https://nps-ms.ca/, which provides MS/MS spectra prediction capabilities for given NPS compounds. Additionally, it offers MS/MS spectra identification against a vast database comprising approximately 8.7 million predicted NPS compounds from DarkNPS and 24.5 million predicted ESI-QToF-MS/MS spectra for these compounds.
Topics: Tandem Mass Spectrometry; Deep Learning; Psychotropic Drugs; Illicit Drugs; Spectrometry, Mass, Electrospray Ionization
PubMed: 38048435
DOI: 10.1021/acs.analchem.3c02413 -
National Science Review Nov 2023Oculomotor behavior has been shown to be correlated with mental disorders in clinics, making it promising for disease diagnosis. Here we developed a thorough oculomotor...
Oculomotor behavior has been shown to be correlated with mental disorders in clinics, making it promising for disease diagnosis. Here we developed a thorough oculomotor test toolkit, involving saccade, smooth pursuit, and fixation, allowing the examination of multiple oculomotor parameters in monkey models induced by psychoactive drugs. Eye movements were recorded after daily injections of phencyclidine (PCP) (3.0 mg/kg), ketamine (0.8 mg/kg) or controlled saline in two macaque monkeys. Both drugs led to robust reduction in accuracy and increment in reaction time during high cognitive-demanding tasks. Saccades, smooth pursuit, and fixation stability were also significantly impaired. During fixation, the involuntary microsaccades exhibited increased amplitudes and were biased toward the lower visual field. Pupillary response was reduced during cognitive tasks. Both drugs also increased sensitivity to auditory cues as reflected in auditory evoked potentials (AEPs). Thus, our animal model induced by psychoactive drugs produced largely similar abnormalities to that in patients with schizophrenia. Importantly, a classifier based on dimension reduction and machine learning could reliably identify altered states induced by different drugs (PCP, ketamine and saline, accuracy = 93%). The high performance of the classifier was reserved even when data from one monkey were used for training and testing the other subject (averaged classification accuracy = 90%). Thus, despite heterogeneity in baseline oculomotor behavior between the two monkeys, our model allows data transferability across individuals, which could be beneficial for future evaluation of pharmaceutical or physical therapy validity.
PubMed: 38046372
DOI: 10.1093/nsr/nwad255 -
Methods in Molecular Biology (Clifton,... 2024Phencyclidine (PCP), a dissociative anesthetic, is a commonly abused recreational drug. In the 1950s, initially tested as an intravenous anesthetic, PCP was discontinued...
Phencyclidine (PCP), a dissociative anesthetic, is a commonly abused recreational drug. In the 1950s, initially tested as an intravenous anesthetic, PCP was discontinued for clinical use due to its severe adverse effects. Since then, it has gained popularity as a recreational drug due to its ability to induce hallucinations and alter perception. PCP can be detected in urine, serum, or plasma by immunoassays and quantified and its presence confirmed by gas or liquid chromatography-mass spectrometry. In the method described here, a deuterated internal standard is added to the sample and the drug is extracted under alkaline conditions. Analysis is conducted using gas chromatography-mass spectrometry (GC-MS). Selected ion monitoring is used for quantitation of PCP.
Topics: Humans; Phencyclidine; Gas Chromatography-Mass Spectrometry; Mass Spectrometry; Substance-Related Disorders; Illicit Drugs
PubMed: 38036841
DOI: 10.1007/978-1-0716-3541-4_37