Muscarinic Research Articles

Efficacy of KarXT on negative symptoms in acute schizophrenia: A post hoc analysis of pooled data from 3 trials

BackgroundCurrently approved antipsychotics do not adequately treat negative symptoms (NS), which are a major determinant of functional disability in schizophrenia. KarXT, an M1 /M4 preferring muscarinic receptor agonist, has shown efficacy as a broad-spectrum monotherapy for the treatment of schizophrenia in participants with acute psychosis. Post hoc analyses evaluated the possibility that NS improve independently of positive symptoms with KarXT in a subgroup of participants with moderate-to-severe NS and no predominance of positive symptoms. MethodsData were pooled from the three pivotal trials of KarXT monotherapy in people with schizophrenia with an acute exacerbation of psychosis. All 3 studies used similar 5-week randomized, double-blind, placebo-controlled designs (modified intention-to-treat sample N = 640). PANSS criteria proposed in the literature identified a subset of study participants (n = 64) with prominent NS. ResultsKarXT was significantly better than placebo on PANSS Marder Negative Factor Scores in the full sample (p < .001; Cohen's d = 0.42) and more so in the prominent NS subgroup (p < .001; Cohen's d = 1.18). Further, the KarXT effect in the NS subgroup remained significant after accounting for changes in positive symptoms, depression/anxiety, disorganization, and hostility. ConclusionsParticipants with prominent NS revealed greater improvement of NS following KarXT therapy than the full sample that persisted after accounting for positive and other symptoms. While these findings must be interpreted with caution, they are consistent with the possibility that NS improvements associated with KarXT are not secondary to improvements in other symptom domains and support further investigation in larger, stable outpatient studies.

Muscarinic receptor agonists in animal models of psychosis: protocol for a systematic review and meta-analysis

Background Muscarinic receptor agonism is a promising mechanism of action for treating psychosis, not present in most D2R-blocking antipsychotics. Xanomeline, an M1/M4-preferring agonist, has shown efficacy in late-stage clinical trials, with more compounds being investigated. Therefore, we aim to synthesize evidence on the preclinical efficacy of muscarinic receptor agonists in animal models of psychosis to provide unique insights and evidence-based information to guide drug development. Methods We plan a systematic review and meta-analysis of in vivo animal studies comparing muscarinic receptor agonists or positive allosteric modulators with control conditions and existing D2R-blocking antipsychotics in animals subjected to any method that induces behavioural changes of relevance for psychosis. We will identify eligible studies by searching multiple electronic databases. At least two independent reviewers will conduct the study selection and data extraction using prespecified forms and assess the risk of bias with the SYRCLE’s tool. Our primary outcomes include locomotor activity and prepulse inhibition measured with standardized mean differences. We will examine other behavioural readouts of relevance for psychosis as secondary outcomes, such as social interaction and cognitive function. We will synthesize the data using multi-level meta-analysis with a predefined random-effects structure, considering the non-independence of the data. In meta-regressions we will explore potential sources of heterogeneity from a predefined list of characteristics of the animal population, model, and intervention. We will assess the confidence in the evidence considering a self-developed instrument thatconsiders the internal and external validity of the evidence. Protocol registration PROSPERO-ID: CRD42024520914

Anti-Amnesic Effect of Agastache rugosa on Scopolamine-Induced Memory Impairment in Mice.

Agastache rugosa, a traditional Asian herbal medicine, is primarily used for digestive problems; yet, its cognitive benefits remain unexplored. This study evaluated the anti-amnesic effects of A. rugosa extract (ARE) on scopolamine (SCO)-induced memory impairment in mice. Mice received 100 or 200 mg/kg ARE orally for 5 days, followed by SCO injection. The ARE demonstrated significant antioxidant (DPPH IC50: 75.3 µg/mL) and anti-inflammatory effects (NO reduction). Furthermore, the ARE significantly improved memory performance in the passive avoidance test (escape latency: 157.2 s vs. 536.9 s), the novel object recognition test (novel object preference: 47.6% vs. 66.3%) and the Morris water maze (time spent in the target quadrant: 30.0% vs. 45.1%). The ARE reduced hippocampal acetylcholinesterase activity (1.8-fold vs. 1.1-fold) while increasing choline acetyltransferase (0.4-fold vs. 1.0-fold) and muscarinic acetylcholine receptor subtype I (0.3-fold vs. 1.6-fold) expression. The ARE improved hippocampal neurogenesis via doublecortin- (0.4-fold vs. 1.1-fold) and KI-67-positive (6.3 vs. 12.0) cells. Therefore, the ARE exerts protective effects against cognitive decline through cholinergic system modulation and antioxidant activity, supporting its potential use as a cognitive enhancer.

Cellular responses following ex vivo lung exposure to the nerve agent VX – Potential for additional treatment targets?

Following inhalation exposure to organophosphorus nerve agents, symptoms rapidly develop and severe respiratory symptoms, such as bronchorrhea and bronchoconstriction are the leading causes of lethality. Nerve agent-induced lung injury is little investigated and the standard treatment for symptomatic relief targets the enzyme acetylcholinesterase and muscarinic acetylcholine and GABAergic receptors. In the present study, cellular responses in lung tissue during the acute (40 min) and extended phase (24 h) following severe exposure to the nerve agent VX have been investigated using an ex vivo rat precision-cut lung slice model including electrostimulation to induce a cholinergic response. Changes in protein amount, cell viability, together with, inflammatory and oxidative stress markers have been determined in both the lung tissue and incubation medium.During the acute phase, VX caused significantly increased airway contraction and decreased airway relaxation. Five micromolar of VX did not affect the sample protein levels and cell viability in lung tissue. Among seven markers of cellular responses investigated in the lung tissue, increased levels of heme oxygenase-1 and matrix metalloproteinase-9 together with decreased levels of glutathione in the incubation medium were observed in the acute phase following VX-exposure compared to electrostimulation only. No difference in cellular response was observed following VX-exposure for 24 h compared to the air control. In comparison, LPS-exposure resulted in time-dependent changes in all markers of inflammation and oxidative response.In conclusion, the present study demonstrated VX-specific patterns of oxidative responses in the lung, as well as, signs of inflammatory response and remodelling of extracellular matrix. These potential mechanisms of tissue injury should be further investigated for their potential as additional therapeutic targets during the acute phase of intoxication.

An Updated Structure of Oxybutynin Hydrochloride.

Oxybutynin (Ditropan), a widely distributed muscarinic antagonist for treating the overactive bladder, has been awaiting a definitive crystal structure for ≈50 years due to the sample and technique limitations. Past reports used powder X-ray diffraction (PXRD) to shed light on the possible packing of the molecule however their model showed some inconsistencies when compared with the 2D chemical structure. These are largely attributed to X-ray-induced photoreduction. Here microcrystal electron diffraction (MicroED) is used to successfully unveil the experimental 3D structure of oxybutynin hydrochloride showing marked improvement over the reported PXRD structure. Using the improved model, molecular docking is applied to investigate the binding mechanism between M3 muscarinic receptor (M3R) and (R)-oxybutynin, revealing essential contacts/residues and conformational changes within the protein pocket. A possible universal conformation is proposed for M3R antagonists, which is valuable for future drug development and optimization. This study underscores the immense potential of MicroED as a complementary technique for elucidating unknown pharmaceutical structures, as well as for protein-drug interactions.

Darifenacin: a promising chitinase 3-like 1 inhibitor to tackle drug resistance in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is among the most aggressive malignancies. Our previous work revealed Chitinase 3-like 1 (CHI3L1) involvement in PDAC resistance to gemcitabine, identifying it as a promising therapeutic target. Here, we aimed to identify putative CHI3L1 inhibitors and to investigate their chemosensitizing potential in PDAC. Docking analysis for CHI3L1 identified promising CHI3L1 inhibitors, including darifenacin (muscarinic receptor antagonist). PDAC cell lines (BxPC-3, PANC-1) and primary PDAC cells were used to evaluate darifenacin's effects on cell growth (Sulforhodamine B, SRB), alone or in combination with gemcitabine or gemcitabine plus paclitaxel. Cytotoxicity against normal immortalized pancreatic ductal cells (HPNE) was assessed. Recombinant protein was used to confirm the impact of darifenacin on CHI3L1-induced PDAC cellular resistance to therapy (SRB assay). Darifenacin's effect on Akt activation was analysed by ELISA. The association between cholinergic receptor muscarinic 3 (CHRM3) expression and therapeutic response was evaluated by immunohistochemistry of paraffin-embedded tissues from surgical resections of a 68 patients' cohort. In silico screening revealed the ability of darifenacin to target CHI3L1 with high efficiency. Darifenacin inhibited PDAC cell growth, with a GI50 of 26 and 13.6 µM in BxPC-3 and PANC-1 cells, respectively. These results were confirmed in primary PDAC-3 cells, while darifenacin showed no cytotoxicity against HPNE cells. Importantly, darifenacin sensitized PDAC cells to standard chemotherapies, reverted CHI3L1-induced PDAC cellular resistance to therapy, and decreased Akt phosphorylation. Additionally, high CHMR3 expression was associated with low therapeutic response to gemcitabine. This work highlights the potential of darifenacin as a chemosensitizer for PDAC treatment.

Activation of Piezo1 channels enhances spontaneous contractions of isolated human bladder strips via acetylcholine release from the mucosa

Enhanced spontaneous bladder contractions (SBCs) have been thought one of the important underlying mechanisms for detrusor overactivity (DO). Piezo1 channel has been demonstrated involved in bladder function and dysfunction in rodents. We aimed to investigate the modulating role of Piezo1 in SBCs activity of human bladder. Human bladder tissues were obtained from 24 organ donors. SBCs of isolated bladder strips were recorded in organ bath. Piezo1 expression was examined with reverse transcription-quantitative polymerase chain reaction and immunofluorescence staining. ATP and acetylcholine release in cultured human urothelial cells was measured. Piezo1 is abundantly expressed in the bladder mucosa. Activation of Piezo1 with its specific agonist Yoda1 (100 nM–100 μM) enhanced the SBCs activity in isolated human bladder strips in a concentration-dependent manner. The effect of Yoda1 mimicked the effect of a low concentration (30 nM) of carbachol, which can be attenuated by removing the mucosa, blocking muscarinic receptors with atropine (1 μM), and blocking purinergic receptors with pyridoxal-phosphate-6-azophenyl-2′,4′-disulfonate (PPADS, 30 μM), but not by tetrodotoxin (1 μM). Activation of urothelial Piezo1 with Yoda1 (30 μM) or hypotonic solution induced the release of ATP and acetylcholine in cultured human urothelial cells. In patients with benign prostatic hyperplasia, greater Piezo1 expression was observed in bladder mucosa from patients with DO than patients without DO. We conclude that upregulation and activation of Piezo1 may contribute to DO generation in patients with bladder outlet obstruction by promoting the urothelial release of ATP and acetylcholine. Inhibition of Piezo1 may be a novel therapeutic approach in the treatment of overactive bladder.

Mini Review: the non-neuronal cardiac cholinergic system in type-2 diabetes mellitus.

Diabetic heart disease remains the leading cause of death in individuals with type-2 diabetes mellitus (T2DM). Both insulin resistance and metabolic derangement, hallmark features of T2DM, develop early and progressively impair cardiovascular function. These factors result in altered cardiac metabolism and energetics, as well as coronary vascular dysfunction, among other consequences. Therefore, gaining a deeper understanding of the mechanisms underlying the pathophysiology of diabetic heart disease is crucial for developing novel therapies for T2DM-associated cardiovascular disease. Cardiomyocytes are equipped with the cholinergic machinery, known as the non-neuronal cardiac cholinergic system (NNCCS), for synthesizing and secreting acetylcholine (ACh) as well as possessing muscarinic ACh receptor for ACh binding and initiating signaling cascade. ACh from cardiomyocytes regulates glucose metabolism and energetics, endothelial function, and among others, in an auto/paracrine manner. Presently, there is only one preclinical animal model - diabetic db/db mice with cardiac-specific overexpression of choline transferase (Chat) gene - to study the effect of activated NNCCS in the diabetic heart. In this mini-review, we discuss the physiological role of NNCCS, the connection between NNCCS activation and cardiovascular function in T2DM and summarize the current knowledge of S-Nitroso-NPivaloyl-D-Penicillamine (SNPiP), a novel inducer of NNCCS, as a potential therapeutic strategy to modulate NNCCS activity for diabetic heart disease.

Reactivation-dependent transfer of fear memory between contexts requires M1 muscarinic receptor stimulation in dorsal hippocampus of male rats.

Memory updating is essential for integrating new information into existing representations. However, this process could become maladaptive in conditions like post-traumatic stress disorder (PTSD), when fear memories generalize to neutral contexts. Previously, we have shown that contextual fear memory malleability in rats requires activation of M1 muscarinic acetylcholine receptors in the dorsal hippocampus. Here, we investigated the involvement of this mechanism in the transfer of contextual fear memories to other contexts using a novel fear memory updating paradigm. Following brief reexposure to a previously fear conditioned context, male rats (n = 8-10/group) were placed into a neutral context to evaluate the transfer of fear memory. We also infused the selective M1 receptor antagonist pirenzepine into the dorsal hippocampus before memory reactivation to try to block this effect. Results support the hypothesis that fear memory can be updated with novel contextual information, but only if rats are reexposed to the originally trained context relatively recently before the neutral context; evidence for transfer was not seen if the fear memory reactivation was omitted or if it occurred 6 h before neutral context exposure. The transferred fear persisted for 4 weeks, and the effect was blocked by M1 antagonism. These findings strongly suggest that fear transfer requires reactivation and destabilization of the original fear memory. The novel preclinical model introduced here, and its implication of muscarinic receptors in this process, could therefore inform therapeutic strategies for PTSD and similar conditions.

Protective role of M3 muscarinic acetylcholine receptor in indomethacin-induced small intestinal injury.

EP4 prostanoid receptor (EP4R) contributes to the intestinal epithelial Cl- secretion, and inhibition of prostaglandin E (PGE) production by non-steroidal anti-inflammatory drugs (NSAIDs) plays a central role in NSAID-induced enteropathy. Although M3 muscarinic acetylcholine receptor (M3R) also contributes to the intestinal epithelial Cl- secretion, it remains unclear whether M3R is involved in NSAID-induced enteropathy due to a lack of selective agents. The present study explored how M3R is involved in the regulation of the intestinal epithelial Cl- secretion and its pathophysiological role in NSAID-induced enteropathy. Using the novel highly-selective M3 positive allosteric modulator PAM-369 that we recently developed, we evaluated the role of M3R in the intestinal epithelial secretion ex vivo by measuring the short circuit current (Isc) of intestinal epithelium with a Ussing chamber system and examined whether or not M3R protects against small intestinal injury in indomethacin-treated mice. Both the PGE1 derivative misoprostol and carbachol similarly increased the Isc in a concentration-dependent manner. The Isc increases were abolished either by receptor antagonists (an EP4R antagonist and a M3R antagonist, respectively) or by removal of extracellular Cl-. PAM-369 enhanced the carbachol-induced Isc by potentiating M3R, which could contribute to enhanced intestinal epithelial secretion. Treatment with PAM-369 ameliorated small intestinal injury in indomethacin-treated mice. Importantly, the M3R expression was significantly up-regulated, and PAM-369 potentiation of M3R was augmented in indomethacin-treated mice compared to untreated mice. These findings show that M3R plays a role in maintaining the intestinal epithelial secretion, which could contribute to protection against indomethacin-induced small intestinal injury. M3R is a promising target for treating or preventing NSAID-induced enteropathy. KEY MESSAGES: PAM-369, the M3 positive allosteric modulator, was used to potentiate M3R. PAM-369 enhanced carbachol-induced Isc in mouse ileum. PAM-369 ameliorated small intestinal injury in indomethacin-treated mice. M3R is a promising target for treating or preventing NSAID-induced enteropathy.

Activation of M4 muscarinic receptors in the striatum reduces tic-like behaviours in two distinct murine models of Tourette syndrome.

Current pharmacotherapies for Tourette syndrome (TS) are often unsatisfactory and poorly tolerated, underscoring the need for novel treatments. Insufficient striatal acetylcholine has been suggested to contribute to tic ontogeny. Thus, we tested whether activating M1 and/or M4 receptors-the two most abundant muscarinic receptors in the striatum-reduced tic-related behaviours in mouse models of TS. Studies were conducted using CIN-d and D1CT-7 mice, two TS models characterized by early-life depletion of striatal cholinergic interneurons and cortical neuropotentiation, respectively. First, we tested the effects of systemic and intrastriatal xanomeline, a selective M1/M4 receptor agonist, on tic-like and other TS-related responses. Then, we examined whether xanomeline effects were reduced by either M1 or M4 antagonists or mimicked by the M1/M3 agonist cevimeline or the M4 positive allosteric modulator (PAM) VU0467154. Finally, we measured striatal levels of M1 and M4 receptors and assessed the impact of VU0461754 on the striatal expression of the neural marker activity c-Fos. Systemic and intrastriatal xanomeline reduced TS-related behaviours in CIN-d and D1CT-7 mice. Most effects were blocked by M4, but not M1, receptor antagonists. VU0467154, but not cevimeline, elicited xanomeline-like ameliorative effects in both models. M4, but not M1, receptors were down-regulated in the striatum of CIN-d mice. Additionally, VU0467154 reduced striatal c-Fos levels in these animals. Activation of striatal M4, but not M1, receptors reduced tic-like manifestations in mouse models, pointing to xanomeline and M4 PAMs as novel putative therapeutic strategies for TS.

Airways Relaxant and Antiasthmatic Activity of Aconitum heterophyllum Wall ex Royle. Roots: A Mechanistic Insight.

Aconitum heterophyllum Wall ex Royle. (Ranunculaceae) is a traditional medicinal herb that has shown extensive pharmacological potential to treat cough, diarrhea, and infectious diseases but no scientific evidence is available to validate its antiasthmatic potential. In this study, we have investigated the tracheal relaxation and antiasthmatic activity of the selected bioactive fraction of A. heterophyllum. Chemical profiling of the most effective fraction obtained via bioassay-guided fractionation was done using LC-MS (Liquid chromatography-mass spectrometry, a technique utilized in the identification, separation, and quantification of known and unknown compounds). Molecular docking analysis of characterized constituents was performed to recognize the binding receptors, followed by an evaluation of the tracheal relaxation ability of active fraction. An acute oral toxicity study of the most effective fraction was done using OECD guidelines 423. Further, the therapeutic efficacy of the fraction was validated in asthma using a guinea pig model of ovalbumin (OVA) induced allergic asthma. The bio-guided activity revealed that hydro-methanolic extract of A. heterophyllum roots (F-1) was the most active fraction. LC-MS analysis of F-1 showed the presence of six major bioactive compounds in F-1. Molecular docking studies revealed strong binding affinities of identified constituents with histaminic receptor (H1) and muscarinic receptor (M3). The ex vivo study demonstrated smooth muscle relaxant activity of F-1 via dysregulating diverse signal transduction pathways viz. histaminic and muscarinic receptors antagonism (non-competitive), stimulation of β2-adrenergic receptor pathway, and soluble guanylyl cyclase activation. The findings of acute oral toxicity studies revealed that F-1 had no toxicity up to the dose of 2000 mg/Kg. The anti-asthmatic therapeutic efficacy of F-1 was further confirmed by the amelioration of respiratory hyperresponsiveness in asthmatic guinea pigs. This is the first evidence-based study showing the antiasthmatic therapeutic potential of the traditionally used herb A. heterophyllum through, computational and animal studies.

Functional anticholinergic activity of drugs classified as strong and moderate on the anticholinergic burden scale on bladder and ileum.

Several medications are commonly administered to older Japanese patients. Since some of them have not been included in previously developed scales to estimate the anticholinergic burden, we have developed a new muscarinic receptor binding-based anticholinergic burden scale. This study aimed to investigate the functional inhibitory effects of 60 medications, classified as anticholinergic burden scales 3 and 2 by the anticholinergic burden scale, on muscarinic receptor-mediated contractions in the bladder and ileum. The relaxation response induced by these drugs on isolated rat bladders and ileum smooth muscles constricted by carbachol was assessed using the organ bath method. All drugs inhibited smooth muscle contractile responses induced by the muscarinic receptor activation in a concentration-dependent manner in the rat bladder and ileum. Notably, variations were observed in the relaxation responses of the drugs, and the function EC50 values were positively correlated with the binding IC50 values in the bladder and ileum. The results of this study provide functional pharmacological evidence for the muscarinic receptor binding-based anticholinergic burden scale. Implementation of this scale may help reduce the risk of constipation and urinary retention, which are common side effects associated with anticholinergic drugs.

An In Silico Approach to Exploring the Antinociceptive Biological Activities of Linalool and its Metabolites.

Pain is characterized by the unpleasant sensory and emotional sensation associated with actual or potential tissue damage, whereas nociception refers to the mechanism by which noxious stimuli are transmitted from the periphery to the CNS. The main drugs used to treat pain are nonsteroidal anti-inflammatory drugs (NSAIDs) and opioid analgesics, which have side effects that limit their use. Therefore, in the search for new drugs with potential antinociceptive effects, essential oils have been studied, whose constituents (monoterpenes) are emerging as a new therapeutic possibility. Among them, linalool and its metabolites stand out. The present study aims to investigate the antinociceptive potential of linalool and its metabolites through a screening using an in silico approach. Molecular docking was used to evaluate possible interactions with important targets involved in antinociceptive activity, such as α2-adrenergic, GABAergic, muscarinic, opioid, adenosinergic, transient potential, and glutamatergic receptors. The compounds in the investigated series obtained negative energies for all enzymes, representing satisfactory interactions with the targets and highlighting the multi-target potential of the L4 metabolite. Linalool and its metabolites have a high likelihood of modulatory activity against the targets involved in nociception and are potential candidates for future drugs.

Abstract 52: HIV-derived Proteins Induce Neuroinflammation, Hypertension, and Sympatho-activation via T cell-dependent mechanisms in the Tg26 Mouse Model

Combination antiretroviral therapy (cART) has extended life expectancy in people living with HIV (PLWH), shifting the primary cause of death to cardiovascular disease (CVD). Hypertension affects over 65% of PLWH. However, the mechanisms underlying HIV-associated hypertension remain poorly understood. In PLWH on cART, T cells persist as viral reservoirs, secreting viral proteins that circulate and localize in the central nervous system (CNS). Here, we used theTg26 mouse model, clinically relevant to cART-controlled PLWH, to test the hypothesis that HIV-derived proteins elevate blood pressure (BP) and induce sympatho-activation through blood-brain barrier disruption, microglial activation, and neuroinflammation. Telemetry-based BP measurements revealed a hypertensive phenotype in male and female Tg26 mice (male: WT=112.3 ±1.3 vs. Tg26=121.9 ±4.0 mmHg; female: WT=110.6 ±3.01 vs. Tg26=120.3 ±6.9 mmHg). Tg26 mice displayed increased sympathetic contribution to BP, indicated by a larger BP decrease following ganglionic blockade compared to WT, with no changes in heart rate responses to muscarinic and β-adrenergic receptor blockade, suggesting increased neurogenic BP regulation. Tg26 mice also showed increased aortic vasoconstriction to phenylephrine (P&lt;0.05). LC/MS analysis revealed no significant differences in circulating catecholamine and metabolites between WT and Tg26 mice (n=5). MRI-based brain perfusion measurements also showed no significant differences, indicating an alteration in brain perfusion is not responsible for increased sympathetic activation. Inhibiting T-cell activation using abatacept, a CTLA-4-Ig fusion protein, significantly reduced BP, sympatho-activation, and phenylephrine-induced vasoconstriction in Tg26 mice (n=5, p&lt;0.05). We analyzed the brains of Tg26 mice to investigate how T cells promote hypertension and sympatho-activation. Quantitative PCR confirmed viral protein expression in brain tissues and microglia of Tg26 mice, associated with increased markers of neuroinflammation, microglia activation, and T-cell infiltration (fold change&gt;1.5, n=6, p&lt;0.05). Tg26 mice also showed increased expression of NADPH oxidases and matrix metalloproteinase. However, there were no changes in the expression of tight junction proteins. Our data suggest that the expression of HIV-derived proteins in Tg26 mice induces central inflammation and T cell infiltration, leading to sympatho-activation through T cell-dependent mechanisms.

Disability and Adverse Effects of Oral Versus Long-Acting Injectable Antipsychotics in Schizophrenia-Spectrum and Bipolar Disorder: A Comparison Based on Data-Driven Taxonomy.

Patients undergoing antipsychotic treatment for psychiatric disorders may experience challenges in functioning, either stemming from the severity of the illness or from the tolerability issues of prescribed medications. The aims of this cross-sectional study are to investigate the impact of adverse effects of antipsychotic drugs on patients' daily life functioning, comparing oral and long-acting injectable (LAI) antipsychotics, and further dividing antipsychotics by receptor-binding profiles based on recently defined data-driven taxonomy. This study involved patients with schizophrenia and bipolar spectrum disorders taking oral or LAI antipsychotics. Disability and functioning levels were assessed using the World Health Organization Disability Assessment Schedule 2.0 (WHODAS), and the adverse effects of medications were evaluated using the Udvalg for Kliniske Undersogelser (UKU) Side Effect Rating Scale and its subscales. The total sample consisted of 126 participants with a diagnosis of schizophrenia-spectrum or bipolar disorder, and included 54 males and 72 females ranging from 18 to 78 years of age (mean45.1, standard deviation 14); 78 patients were taking oral antipsychotics and 48 were taking LAI antipsychotics, with subcategories of muscarinic (31), adrenergic/low dopamine (25), serotonergic/dopaminergic (23), dopaminergic (1), LAI muscarinic (15), LAI adrenergic (6), and LAI serotonergic/dopaminergic (25). The UKU total score for adverse effects showed significant correlations with WHODAS total score (ρ=0.475; p<0.001). Compared with oral antipsychotics, LAIs showed significantly lower scores in psychological (p=0.014), autonomic (p=0.008), other (p=0.004), and sexual adverse effects (p=0.008), as well as the UKU total score (p=0.002). The Kruskal-Wallis test showed a significant difference in adverse effects between LAI and oral muscarinic subgroups, with LAIs having lower scores compared with antipsychotics binding to muscarinic receptors (p=0.043). These findings indicate clinically relevant differences in adverse effects among formulations, warranting further investigation for future observational studies.

Impact of salivary flow inhibition on masticatory behaviours in healthy individuals.

It remains unclear how the salivary flow and the fat content of food affect bolus formation during mastication. We aimed to clarify: (1) how hyposalivation affects jaw-closing and hyoid-elevating muscle activities in bolus formation, and (2) if the effect of hyposalivation on muscle activity depends on the fat content of food. Eighteen healthy male volunteers were instructed to freely ingest four test foods: Plain, Fat without seasoning, Fat with seasoning, and Soft rice crackers. Masseter and suprahyoid electromyographic activities were recorded before and 30 min after the administration of atropine sulfate, a muscarinic receptor antagonist that induces hyposalivation. Hyposalivation extended the masticatory duration significantly in all the test foods except Fat with seasoning. Masticatory cycle time was significantly longer with vs without hyposalivation for the Soft (p = .011). Suprahyoid activity/cycle was significantly greater with vs without hyposalivation (p = .013). Masticatory cycle time was significantly longer at the late stage with vs without hyposalivation for the Soft (p < .001). Suprahyoid activity/cycle was significantly greater at the middle (p = .045) and late stages (p = .002) with vs without hyposalivation for the Soft and greater at the late stage with vs without hyposalivation for the Plain (p = .043). Changes in masticatory cycle time and suprahyoid activity/cycle for these foods had significantly positive relationship (p < .001). Hyposalivation-induced changes in masticatory behaviours resulted from the middle and late stage suprahyoid activity. Fat content and seasoning compensate for salivary flow inhibition.

Ophthalmic effects of Bitis atropos (Berg Adder) envenomation

Objective: Bitis atropos, commonly known as the Berg Adder, is a venomous viperid found in Southern Africa. Envenomation is rare, with reported cases primarily exhibiting cytotoxic, neurotoxic, and myotoxic effects, including severe systemic manifestations and ophthalmologic complications such as ptosis, mydriasis, and loss of accommodation. However, the underlying pathophysiology of these sequelae remains poorly understood. Case: We present the case of a 26-year-old male who suffered severe envenomation by a Berg Adder in the Limpopo Province, South Africa. Within minutes of the bite, the patient experienced hypoesthesia, progressive dyspnea, and loss of consciousness, followed by prolonged intensive care management. Ophthalmic examination revealed bilateral dilated pupils, right ptosis, and impaired accommodation, alongside generalized muscle weakness, anosmia, ageusia, and dysphagia. Despite the absence of antivenom, the patient’s condition showed gradual improvement over a 127-day follow-up period. Notably, the pupils exhibited denervation supersensitivity, similar to Adie’s tonic pupil, and responded well to low-dose pilocarpine. Conclusion: The clinical features observed, particularly the ophthalmoplegic triad, can be attributed to the effects of phospholipase A2 proteins in the venom, which disrupt cholinergic transmission at muscarinic receptors. This case underscores the complexity of Berg Adder envenomation and highlights the variability in recovery timelines for different neuro-ophthalmic effects. This case provides valuable insights into the pathophysiology and management of severe Berg Adder envenomation, emphasizing the role of targeted therapeutic interventions such as pilocarpine in mitigating long-term sequelae.

Synthesis and nootropic activity prediction of some 4-(aminomethyl)-1-benzylpyrrolidin-2-one derivatives structurally related with nebracetam

The aim. Search for new biologically active substances with improved nootropic parameters among analogues of 4-(aminomethyl)-1-benzylpyrrolidine-2-one (Nebracetam). Materials and methods. The required reagents were purified using standard techniques. The elemental analysis was performed on a "Hewlett Packard" automatic analyzer M-180 company. 1H NMR spectra were recorded on Varian Gemini 400 MHz spectrometer in DMSO-d6 as a solvent. LC/MS spectra were recorded with a PE SCIEX API 150EX liquid chromatograph equipped. The Autodock 4.2 software package was used for molecular docking. The active centers of the peptides (PDB ID: 5CXV, 6PV7) was used as the biologycal targets. Results and discussion. Basic and alternative methods (1 and 2) of obtaining were used to synthesise target analogues of 4-(aminomethyl)-1-R-benzylpyrrolidine-2-one. As a result of synthetic studies, an optimized method with an alternative method has been proposed. The advantages include reducing the duration and number of synthesis stages and avoiding the use of sodium azide, a highly toxic and hazardous substance. Molecular docking of the synthesized compounds at well-documented acetylcholine receptor sites indicates that all tested molecules will contribute to the manifestation of nootropic activity to varying degrees through cholinergic neurotransmission mechanisms. This is evidenced by the calculated docking values in relation to the muscarinic target. According to the docking results, it was found that depending on the enantiomeric configuration, the molecules formed stable complexes with the target and had characteristic binding modes both in the orthosteric site and in the extracellular vestibule (site of positive allosteric modulation of mAChR). It indicates the prospects of modifying the "nebracetam scaffold" at the phenyl fragment with halogen substituents. Conclusions. An effective method for synthesising analogues of 4-(aminomethyl)-1-R-benzylpyrrolidin-2-ones has been developed. The molecular docking revealed potential mechanisms of nootropic action of the synthesized derivatives as potential agonists and positive allosteric modulators of the muscarinic receptor

Higher levels of AKT-interacting protein in the frontal pole from people with schizophrenia are limited to a sub-group who have a marked deficit in cortical muscarinic M1 receptors

We are studying the molecular pathology of a sub-group within schizophrenia (∼ 25 %: termed Muscarinic Receptor Deficit subgroup of Schizophrenia (MRDS)) who can be separated because they have very low levels of cortical muscarinic M1 receptors (CHRM1). Based on our transcriptomic data from Brodmann's area ((BA) 9, 10 and 33 (controls, schizophrenia and mood disorders) and the cortex of the CHRM1−/− mouse (a molecular model of aberrant CHRM1 signaling), we predicted levels of AKT interacting protein (AKTIP), but not tubulin alpha 1b (TUBA1B) or AKT serine/threonine kinase 1 (AKT1) and pyruvate dehydrogenase kinase 1 (PDK1) (two AKTIP-functionally associated proteins), would be changed in MRDS. Hence, we used Western blotting to measure AKTIP (BA 10: controls, schizophrenia and mood disorders; BA 9: controls and schizophrenia) plus TUBA1B, AKT1 and PDK1 (BA 10: controls and schizophrenia) proteins. The only significant change with diagnosis was higher levels of AKTIP protein in BA 10 (Cohen's d = 0.73; p = 0.02) in schizophrenia compared to controls due to higher levels of AKTIP only in people with MRDS (Cohen's d = 0.80; p = 0.03). As AKTIP is involved in AKT1 signaling, our data suggests that signaling pathway is particularly disturbed in BA 10 in MRDS.