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Journal of Physiology and Pharmacology... Dec 2018Acrylamide (ACR) is a chemical compound, that forms in starchy food products during cooking at high-temperatures, including frying, baking, and roasting. ACR is a known... (Review)
Review
Acrylamide (ACR) is a chemical compound, that forms in starchy food products during cooking at high-temperatures, including frying, baking, and roasting. ACR is a known lethal neurotoxin. The presented review suggests that the mechanism of ACR's neurotoxicity may be related to an impaired cholinergic transmission in the central and peripheral nervous system and redox imbalance. These may not only affect ongoing brain functions but also participate in etiology of neurodegeneration.
Topics: Acrylamide; Animals; Cholinergic Agents; Humans; Nervous System; Neurotoxins
PubMed: 30898983
DOI: 10.26402/jpp.2018.6.03 -
Trends in Pharmacological Sciences Dec 2022Modern interest in muscarinic acetylcholine receptor (mAChR) activators for schizophrenia began in the 1990s when xanomeline, an M/M-preferring mAChR agonist developed... (Review)
Review
Modern interest in muscarinic acetylcholine receptor (mAChR) activators for schizophrenia began in the 1990s when xanomeline, an M/M-preferring mAChR agonist developed for cognitive symptoms of Alzheimer's disease (AD), had unexpected antipsychotic activity. However, strategies to address tolerability concerns associated with activation of peripheral mAChRs were not available at that time. The discovery of specific targeted ligands and combination treatments to reduce peripheral mAChR engagement have advanced the potential of mAChR activators as effective treatments for psychotic disorders. This review provides perspectives on the background of the identification of mAChRs as potential antipsychotics, advances in the preclinical understanding of mAChRs as targets, and the current state of mAChR activators under active clinical development for schizophrenia.
Topics: Humans; Muscarinic Agonists; Receptors, Muscarinic; Schizophrenia; Psychotic Disorders; Acetylcholine; Receptor, Muscarinic M1
PubMed: 36273943
DOI: 10.1016/j.tips.2022.09.006 -
The Cochrane Database of Systematic... Mar 2018Tardive dyskinesia (TD) remains a troublesome adverse effect of conventional antipsychotic (neuroleptic) medication. It has been proposed that TD could have a component... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Tardive dyskinesia (TD) remains a troublesome adverse effect of conventional antipsychotic (neuroleptic) medication. It has been proposed that TD could have a component of central cholinergic deficiency. Cholinergic drugs have been used to treat TD.
OBJECTIVES
To determine the effects of cholinergic drugs (arecoline, choline, deanol, lecithin, meclofenoxate, physostigmine, RS 86, tacrine, metoxytacrine, galantamine, ipidacrine, donepezil, rivastigmine, eptastigmine, metrifonate, xanomeline, cevimeline) for treating antipsychotic-induced TD in people with schizophrenia or other chronic mental illness.
SEARCH METHODS
An electronic search of the Cochrane Schizophrenia Group's Study-Based Register of Trials (16 July 2015 and April 2017) was undertaken. This register is assembled by extensive searches for randomised controlled trials in many electronic databases, registers of trials, conference proceedings and dissertations. References of all identified studies were searched for further trial citations.
SELECTION CRITERIA
We included reports identified by the search if they were of controlled trials involving people with antipsychotic-induced TD and chronic mental illness, who had been randomly allocated to either a cholinergic agent or to a placebo or no intervention. Two review authors independently assessed the methodological quality of the trials.
DATA COLLECTION AND ANALYSIS
Two review authors extracted data and, where possible, estimated risk ratios (RR) or mean differences (MD), with 95% confidence intervals (CI). We analysed data on an intention-to-treat basis, with the assumption that people who left early had no improvement. We assessed risk of bias and created a 'Summary of findings' table using GRADE.
MAIN RESULTS
We included 14 studies investigating the use of cholinergic drugs compared with placebo published between 1976 and 2014. All studies involved small numbers of participants (five to 60 people). Three studies that investigated the new cholinergic Alzheimer drugs for the treatment of TD are new to this update. Overall, the risk of bias in the included studies was unclear, mainly due to poor reporting; allocation concealment was not described, generation of the sequence was not explicit, studies were not clearly blinded, we are unsure if data are incomplete, and data were often poorly or selectively reported.We are uncertain about the effect of new or old cholinergic drugs on no clinically important improvement in TD symptoms when compared with placebo; the quality of evidence was very low (RR 0.89, 95% CI 0.65 to 1.23; 27 people, 4 RCTs). Eight trials found that cholinergic drugs may make little or no difference to deterioration of TD symptoms (low-quality evidence, RR 1.11, 95% CI 0.55 to 2.24; 147 people). Again, due to very low-quality evidence, we are uncertain about the effects on mental state (RR 0.50, 95% CI 0.10 to 2.61; 77 people, 5 RCTs), adverse events (RR 0.56, 95% CI 0.15 to 2.14; 106 people, 4 RCTs), and leaving the study early (RR 1.09,95% CI 0.56 to 2.10; 288 people 12 RCTs). No study reported on social confidence, social inclusion, social networks, or personalised quality of life.
AUTHORS' CONCLUSIONS
TD remains a major public health problem. The clinical effects of both older cholinergic drugs and new cholinergic agents, now used for treating Alzheimer's disease, are unclear, as too few, too small studies leave many questions unanswered. Cholinergic drugs should remain of interest to researchers and currently have little place in routine clinical work. However, with the advent of new cholinergic agents now used for treating Alzheimer's disease, scope exists for more informative trials. If these new cholinergic agents are to be investigated for treating people with TD, their effects should be demonstrated in large well-designed, conducted and reported randomised trials.
Topics: Antipsychotic Agents; Cholinergic Agents; Dyskinesia, Drug-Induced; Humans; Patient Dropouts; Randomized Controlled Trials as Topic
PubMed: 29553158
DOI: 10.1002/14651858.CD000207.pub2 -
Cell Reports Oct 2023The amygdala, cholinergic basal forebrain, and higher-order auditory cortex (HO-AC) regulate brain-wide plasticity underlying auditory threat learning. Here, we perform...
The amygdala, cholinergic basal forebrain, and higher-order auditory cortex (HO-AC) regulate brain-wide plasticity underlying auditory threat learning. Here, we perform multi-regional extracellular recordings and optical measurements of acetylcholine (ACh) release to characterize the development of discriminative plasticity within and between these brain regions as mice acquire and recall auditory threat memories. Spiking responses are potentiated for sounds paired with shock (CS+) in the lateral amygdala (LA) and optogenetically identified corticoamygdalar projection neurons, although not in neighboring HO-AC units. Spike- or optogenetically triggered local field potentials reveal enhanced corticofugal-but not corticopetal-functional coupling between HO-AC and LA during threat memory recall that is correlated with pupil-indexed memory strength. We also note robust sound-evoked ACh release that rapidly potentiates for the CS+ in LA but habituates across sessions in HO-AC. These findings highlight a distributed and cooperative plasticity in LA inputs as mice learn to reappraise neutral stimuli as possible threats.
Topics: Mice; Animals; Acoustic Stimulation; Learning; Basolateral Nuclear Complex; Amygdala; Acetylcholine; Cholinergic Agents
PubMed: 37742187
DOI: 10.1016/j.celrep.2023.113167 -
Translational Psychiatry Mar 2017Depression is one of the most common psychiatric conditions. Symptoms can lead to significant disability, which result in impairments in overall quality of life. Though... (Review)
Review
Depression is one of the most common psychiatric conditions. Symptoms can lead to significant disability, which result in impairments in overall quality of life. Though there are many approved antidepressant treatments for depression-including selective serotonin reuptake inhibitors, tricyclic antidepressants and monoamine oxidase inhibitors-about a third of patients do not respond to these medications. Therefore, it is imperative for drug discovery to continue towards the development of novel and rapidly acting compounds, especially for patients with treatment-resistant depression. After a brief review of the efficacy of approved antidepressant therapies, we will discuss experimental medication treatments for depression. Specifically, we examine novel medications that are thought to primarily modulate the glutamatergic, cholinergic and opioid systems to achieve antidepressant efficacy. We also give examples of anti-inflammatories, neurokinin-1 modulators, vasopressin antagonists and neurogenesis enhancers that may have a therapeutic role in treatment-resistant depression. The current pipeline of antidepressant treatments is shifting towards medications with novel mechanisms, which may lead to important, life-changing discoveries for patients with severe disease.
Topics: Analgesics, Opioid; Anti-Inflammatory Agents; Antidepressive Agents; Antidiuretic Hormone Receptor Antagonists; Cholinergic Agents; Depressive Disorder; Depressive Disorder, Major; Drug Discovery; Excitatory Amino Acid Antagonists; Humans; Neurokinin-1 Receptor Antagonists
PubMed: 28323287
DOI: 10.1038/tp.2017.33 -
Frontiers in Immunology 2021Neurological and immunological signals constitute an extensive regulatory network in our body that maintains physiology and homeostasis. The cholinergic system plays a... (Review)
Review
Neurological and immunological signals constitute an extensive regulatory network in our body that maintains physiology and homeostasis. The cholinergic system plays a significant role in neuroimmune communication, transmitting information regarding the peripheral immune status to the central nervous system (CNS) and vice versa. The cholinergic system includes the neurotransmitter\ molecule, acetylcholine (ACh), cholinergic receptors (AChRs), choline acetyltransferase (ChAT) enzyme, and acetylcholinesterase (AChE) enzyme. These molecules are involved in regulating immune response and playing a crucial role in maintaining homeostasis. Most innate and adaptive immune cells respond to neuronal inputs by releasing or expressing these molecules on their surfaces. Dysregulation of this neuroimmune communication may lead to several inflammatory and autoimmune diseases. Several agonists, antagonists, and inhibitors have been developed to target the cholinergic system to control inflammation in different tissues. This review discusses how various molecules of the neuronal and non-neuronal cholinergic system (NNCS) interact with the immune cells. What are the agonists and antagonists that alter the cholinergic system, and how are these molecules modulate inflammation and immunity. Understanding the various functions of pharmacological molecules could help in designing better strategies to control inflammation and autoimmunity.
Topics: Animals; Autoimmunity; Cholinergic Agents; Humans; Inflammation; Mice; Neurons; Receptors, Cholinergic; Signal Transduction
PubMed: 33936095
DOI: 10.3389/fimmu.2021.660342 -
International Journal of Molecular... Sep 2022Locomotion is a basic motor act essential for survival. Amongst other things, it allows animals to move in their environment to seek food, escape predators, or seek... (Review)
Review
Locomotion is a basic motor act essential for survival. Amongst other things, it allows animals to move in their environment to seek food, escape predators, or seek mates for reproduction. The neural mechanisms involved in the control of locomotion have been examined in many vertebrate species and a clearer picture is progressively emerging. The basic muscle synergies responsible for propulsion are generated by neural networks located in the spinal cord. In turn, descending supraspinal inputs are responsible for starting, maintaining, and stopping locomotion as well as for steering and controlling speed. Several neurotransmitter systems play a crucial role in modulating the neural activity during locomotion. For instance, cholinergic inputs act both at the spinal and supraspinal levels and the underlying mechanisms are the focus of the present review. Much information gained on supraspinal cholinergic modulation of locomotion was obtained from the lamprey model. Nicotinic cholinergic inputs increase the level of excitation of brainstem descending command neurons, the reticulospinal neurons (RSNs), whereas muscarinic inputs activate a select group of hindbrain neurons that project to the RSNs to boost their level of excitation. Muscarinic inputs also reduce the transmission of sensory inputs in the brainstem, a phenomenon that could help in sustaining goal directed locomotion. In the spinal cord, intrinsic cholinergic inputs strongly modulate the activity of interneurons and motoneurons to control the locomotor output. Altogether, the present review underlines the importance of the cholinergic inputs in the modulation of locomotor activity in vertebrates.
Topics: Animals; Cholinergic Agents; Lampreys; Locomotion; Motor Neurons; Neurotransmitter Agents; Spinal Cord
PubMed: 36142651
DOI: 10.3390/ijms231810738 -
Neuron Nov 2022In this issue of Neuron, Li et al. (2022) identify and genetically target two sub-populations of cholinergic neurons in the basal forebrain. They show that these...
In this issue of Neuron, Li et al. (2022) identify and genetically target two sub-populations of cholinergic neurons in the basal forebrain. They show that these cholinergic subtypes have distinct projection patterns, electrophysiological phenotypes, and behavioral functions.
Topics: Basal Forebrain; Cholinergic Neurons; Electrophysiological Phenomena; Cholinergic Agents
PubMed: 36395751
DOI: 10.1016/j.neuron.2022.10.009 -
Scientific Reports Aug 2020Wild mushroom foraging involves a high risk of unintentional consumption of poisonous mushrooms which is a serious health concern. This problem arises due to the close...
Wild mushroom foraging involves a high risk of unintentional consumption of poisonous mushrooms which is a serious health concern. This problem arises due to the close morphological resemblances of toxic mushrooms with edible ones. The genus Inocybe comprises both edible and poisonous species and it is therefore important to differentiate them. Knowledge about their chemical nature will unambiguously determine their edibility and aid in an effective treatment in case of poisonings. In the present study, the presence of volatile toxic metabolites was verified in Inocybe virosa by gas chromatography. Methyl palmitate, phenol, 3,5-bis (1,1-dimethyl ethyl) and phytol were the identified compounds with suspected toxicity. The presence of the toxin muscarine was confirmed by liquid chromatography. The in vitro study showed that there was negligible effect of the digestion process on muscarine content or its toxicity. Therefore, the role of muscarine in the toxicity of Inocybe virosa was studied using a bioassay wherein metameters such as hypersalivation, immobility, excessive defecation, heart rate and micturition were measured. Administration of muscarine resulted in an earlier onset of symptoms and the extract showed a slightly stronger muscarinic effect in comparison to an equivalent dose of muscarine estimated in it. Further, the biological fate of muscarine was studied by pharmacokinetics and gamma scintigraphy in New Zealand white rabbits. Significant amount of the toxin was rapidly and effectively concentrated in the thorax and head region. This study closely explains the early muscarinic response such as miosis and salivation in mice. By the end of 24 h, a relatively major proportion of muscarine administered was accumulated in the liver which stands as an explanation to the hepatotoxicity of Inocybe virosa. This is one of the rare studies that has attempted to understand the toxic potential of muscarine which has previously been explored extensively for its pharmaceutical applications.
Topics: Agaricales; Animals; Brain Chemistry; Cell Line; Cell Survival; Female; Gas Chromatography-Mass Spectrometry; Humans; Mice; Muscarine; Palmitates; Phenol; Phytol; Rabbits; Thorax; Toxins, Biological
PubMed: 32792538
DOI: 10.1038/s41598-020-70196-7 -
Journal of Neuroscience Methods Feb 2016Models of epileptiform activity in vitro have many advantages for recording and experimental manipulation. Neural tissues can be maintained in vitro for hours, and in... (Review)
Review
Models of epileptiform activity in vitro have many advantages for recording and experimental manipulation. Neural tissues can be maintained in vitro for hours, and in neuronal or organotypic slice cultures for several weeks. A variety of drugs and other agents increase activity in these in vitro conditions, in many cases resulting in epileptiform activity, thus providing a direct model of symptomatic seizures. We review these preparations and the experimental manipulations used to induce epileptiform activity. The most common of drugs used are GABAA receptor antagonists and potassium channel blockers (notably 4-aminopyridine). Muscarinic agents also can induce epileptiform synchronization in vitro, and include potassium channel inhibition amongst their cellular actions. Manipulations of extracellular ions are reviewed in another paper in this special issue, as are ex vivo slices prepared from chronically epileptic animals and from people with epilepsy. More complex slices including extensive networks and/or several connected brain structures can provide insights into the dynamics of long range connections during epileptic activity. Visualization of slices also provides opportunities for identification of living neurons and for optical recording/stimulation and manipulation. Overall, the analysis of the epileptiform activity induced in brain tissue in vitro has played a major role in advancing our understanding of the cellular and network mechanisms of epileptiform synchronization, and it is expected to continue to do so in future.
Topics: Animals; Cells, Cultured; Cholinergic Agents; Cortical Synchronization; Disease Models, Animal; Epilepsy; GABA Antagonists; Humans; Nerve Net; Organ Culture Techniques; Potassium Channel Blockers
PubMed: 26484784
DOI: 10.1016/j.jneumeth.2015.10.006