Evolutional study on acetylcholine expression

Weep and sweep and the broom: tuft cell acetylcholine limits the worm

Two studies defined how tuft cell acetylcholine promotes parasite expulsion. Billip et al. demonstrated that acetylcholine increases water secretion, to promote the 'weep' response. Ndjim et al. found that tuft cell acetylcholine has a direct effect on worm fecundity. Both processes are only effective in the remodeled epithelium when the rare tuft cells have become abundant.

A non-adaptationist hypothesis of play behaviour

Play is a suite of apparently non-functional, pleasurable behaviours observed in human and non-human animals. Although the phenomenon has been studied extensively, no adaptationist behavioural theory of how play evolved can be supported by the available evidence. However, the advancement of the extended evolutionary synthesis and developments in systems biology offer alternative avenues for non-adaptationist physiological hypotheses. I therefore propose a hypothesis of play, based upon a complex ACh activity that is under agential control of the organism, whereby play initiates ACh-mediated feedforward and feedback processes which act to: (i) regulate metabolic processes; (ii) form new ACh receptors via ACh mRNA activity; (iii) mediate attention, memory consolidation and learning; and (iv) mediate social behaviours, reproduction and embryonic development. However, play occurs across taxa, but does not occur across all taxonomic groups or within all species of a taxonomic group. Thus, to support the validity of the proposed hypothesis, I further propose potential explanations for this anomaly, which include sampling and observer biases, altricial versus precocial juvenile development, and the influence of habitat niche and environmental conditions on behaviour. The proposed hypothesis thus offers new avenues for study in both the biological and social sciences, in addition to having potential applications in applied sciences, such as animal welfare and biomedical research. Crucially, it is hoped that this hypothesis will promote further study of a valid and behaviourally significant, yet currently enigmatic, biological phenomenon.

Role of acetylcholine and acetylcholinesterase in improving abiotic stress resistance/tolerance

Abiotic stress that plants face may impact their growth and limit their productivity. In response to abiotic stress, several endogenous survival mechanisms get activated, including the synthesis of quaternary amines in plants. Acetylcholine (ACh), a well-known quaternary amine, and its components associated with cholinergic signaling are known to contribute to a variety of physiological functions. However, their role under abiotic stress is not well documented. Even after several studies, there is a lack of a comprehensive understanding of how cholinergic components mitigate abiotic stress in plants. Acetylcholine hydrolyzing enzyme acetylcholinesterase (AChE) belongs to the GDSL lipase/acylhydrolase protein family and has been found in several plant species. Several studies have demonstrated that GDSL members are involved in growth, development, and abiotic stress. This review summarizes all the possible mitigating effects of the ACh-AChE system on abiotic stress tolerance and will try to highlight all the progress made so far in this field.

Microbiota-Gut-Brain Axis Dysregulation in Alzheimer's Disease: Multi-Pathway Effects and Therapeutic Potential

An essential regulator of neurodegenerative conditions like Alzheimer's disease (AD) is the gut microbiota. Alterations in intestinal permeability brought on by gut microbiota dysregulation encourage neuroinflammation, central immune dysregulation, and peripheral immunological dysregulation in AD, as well as hasten aberrant protein aggregation and neuronal death in the brain. However, it is unclear how the gut microbiota transmits information to the brain and how it influences brain cognition and function. In this review, we summarized the multiple pathways involved in the gut microbiome in AD and provided detailed treatment strategies based on the gut microbiome. Based on these observations, this review also discusses the problems, challenges, and strategies to address current therapeutic strategies.

Microbiota-derived acetylcholine can promote gut motility in Drosophila melanogaster

The gut microbiota is crucial for intestinal health, including gastrointestinal (GI) motility. How commensal bacterial species influence GI motility has not been fully elucidated. A major factor of GI motility is the gut contraction promoting the propulsive movement of orally ingested materials. Here, we developed a method to monitor and quantify gut contractions in living Drosophila melanogaster larvae. We found that the culture medium of an isolated strain Lactiplantibacillus plantarum Lsi promoted gut contraction in vivo, which was not observed in Leuconostoc sp. Leui nor Acetobacter persici Ai culture medium. To identify bacteria-derived metabolites, we performed metabolome analysis of the culture media by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Of the 66 metabolites detected, we found that some metabolites changed in a species-specific manner. Among them, acetylcholine was specifically produced by L. plantarum. Feeding exogenous acetylcholine increased the frequency of gut contractions, which was blocked by D-tubocurarine, an inhibitor of nicotinic acetylcholine receptors. In this study, we propose a mechanism by which the gut microbiota influences Drosophila gut motility. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.

A hypothesis of teleological evolution, via endogenous acetylcholine, nitric oxide, and calmodulin pathways

The Extended Evolutionary Synthesis (EES) addresses the issues in evolutionary biology which cannot be explained by neo-Darwinian theory. The EES paradigm recognises teleology and agency in living systems, and identifies that organisms can directly affect their evolutionary trajectory in a goal-directed manner, yet the physiological pathways via which this occurs remain unidentified. Here, I propose a physiological pathway via which organisms can alter their genotype and phenotype by making behavioural decisions with respect their activity levels, partitioning of resources either toward growth, defence against disease, or their behavioural response to stressors. Specifically, I hypothesize that agential, teleological decisions mediated by acetylcholine result in induced nitric oxide (NO) activity, which regulates metabolism, blood flow, and immune response. Nitric oxide, however, is also a key epigenetic molecule, being involved in DNA acetylation, methylation, and de-methylation. Further, NO alters the histone complexes which scaffold nuclear DNA strands, and is thus a good candidate in identifying a system which allows an organisms to make teleological genetic changes. The proposed mechanisms of inheritance of these genetic changes is via the paternal line, whereby epigenetic changes in the somatic Sertoli cells in animals are transcribed by mRNA and included in the germline cells - the male gametes. The microsporangium in plants, and the sporophore cells in fungi, meanwhile, are proposed to form similar systems in response to sensory detection of stressors. Whilst the hypothesis is presented as a simplified model for future testing, it opens new avenues for study in evolutionary biology.

Contributions of Non-Neuronal Cholinergic Systems to the Regulation of Immune Cell Function, Highlighting the Role of α7 Nicotinic Acetylcholine Receptors

Loewi's discovery of acetylcholine (ACh) release from the frog vagus nerve and the discovery by Dale and Dudley of ACh in ox spleen led to the demonstration of chemical transmission of nerve impulses. ACh is now well-known to function as a neurotransmitter. However, advances in the techniques for ACh detection have led to its discovery in many lifeforms lacking a nervous system, including eubacteria, archaea, fungi, and plants. Notably, mRNAs encoding choline acetyltransferase and muscarinic and nicotinic ACh receptors (nAChRs) have been found in uninnervated mammalian cells, including immune cells, keratinocytes, vascular endothelial cells, cardiac myocytes, respiratory, and digestive epithelial cells. It thus appears that non-neuronal cholinergic systems are expressed in a variety of mammalian cells, and that ACh should now be recognized not only as a neurotransmitter, but also as a local regulator of non-neuronal cholinergic systems. Here, we discuss the role of non-neuronal cholinergic systems, with a focus on immune cells. A current focus of much research on non-neuronal cholinergic systems in immune cells is α7 nAChRs, as these receptors expressed on macrophages and T cells are involved in regulating inflammatory and immune responses. This makes α7 nAChRs an attractive potential therapeutic target.

Effects of polystyrene microplastics on the metabolic level of Pseudomonas aeruginosa

Given the widespread presence of Pseudomonas aeruginosa in water and its threat to human health, the metabolic changes in Pseudomonas aeruginosa when exposed to polystyrene microplastics (PS-MPs) exposure were studied, focusing on molecular level. Through non-targeted metabolomics, a total of 64 differential metabolites were screened out under positive ion mode and 44 under negative ion mode. The content of bacterial metabolites changed significantly, primarily involving lipids, nucleotides, amino acids, and organic acids. Heightened intracellular oxidative damage led to a decrease in lipid molecules and nucleotide-related metabolites. The down-regulation of amino acid metabolites, such as L-Glutamic and L-Proline, highlighted disruptions in cellular energy metabolism and the impaired ability to synthesize proteins as a defense against oxidation. The impact of PS-MPs on organic acid metabolism was evident in the inhibition of pyruvate and citrate, thereby disrupting the cells' normal participation in energy cycles. The integration of Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that PS-MPs mainly caused changes in metabolic pathways, including ABC transporters, Aminoacyl-tRNA biosynthesis, Purine metabolism, Glycerophospholipid metabolism and TCA cycle in Pseudomonas aeruginosa. Most of the differential metabolites enriched in these pathways were down-regulated, demonstrating that PS-MPs hindered the expression of metabolic pathways, ultimately impairing the ability of cells to synthesize proteins, DNA, and RNA. This disruption affected cell proliferation and information transduction, thus hampering energy circulation and inhibiting cell growth. Findings of this study supplemented the toxic effects of microplastics and the defense mechanisms of microorganisms, in turn safeguarding drinking water safety and human health.

Oxidized/unmodified-polyethylene microplastics neurotoxicity in mice: Perspective from microbiota-gut-brain axis

Microplastics (MPs) are inevitably oxidized in the environment, and their potential toxicity to organisms has attracted wide attention. However, the neurotoxicity and mechanism of oxidized polyethylene (Ox-PE) MPs to organisms remain unclear. Herein, we prepared oxidized low-density polyethylene (Ox-LDPE) and established a model of MPs exposure by continuously orally gavage of C57BL/6 J mice with LDPE-MPs/Ox-LDPE-MPs for 28 days with or without oral administration of Lactobacillus plantarum DP189 and galactooligosaccharides (DP189&GOS). The experimental results indicated that LDPE-MPs or Ox-LDPE-MPs caused several adverse effects in mice, mainly manifested by behavioral changes, disruption of the intestinal and blood-brain barrier (BBB), and simultaneous oxidative stress, inflammatory reactions, and pathological damage in the brain and intestines. Brain transcriptomic analysis revealed that the cholinergic synaptic signaling pathways, which affect cognitive function, were significantly disrupted after exposure to LDPE-MPs or Ox-LDPE-MPs. Real-time quantitative polymerase chain reaction and Western Blotting results further demonstrated that the critical genes (Slc5a7, Chat and Slc18a3) and proteins (Chat and Slc18a3) in the cholinergic synaptic signaling pathway were significantly down-regulated after exposure to LDPE-MPs or Ox-LDPE-MPs. These alterations lead to reduced acetylcholine concentration, which causes cognitive dysfunction in mice. Importantly, the DP189&GOS interventions effectively mitigated the MPs-induced cognitive dysfunction and intestinal microbiota alteration, improved intestinal and BBB integrity, attenuated the oxidative stress and inflammatory response, and also saw a rebound in the release of acetylcholine. These results indicated that LDPE-MPs and Ox-LDPE-MPs exert neurotoxic effects on mice by inducing oxidative stress, inflammatory responses, and dysregulation of cholinergic signaling pathways in the mouse brain. That probiotic supplementation is effective in attenuating MPs-induced neurotoxicity in mice. Overall, this study reveals the potential mechanisms of neurotoxicity of LDPE-MPs and Ox-LDPE-MPs on mice and their improvement measures, necessary to assess the potential risks of plastic contaminants to human health.

Expression of the non-neuronal cholinergic system components in Malpighian tubules of Mythimna separata and evidence for non-neuronal acetylcholine synthesis

The non-neuronal cholinergic system, widely distributed in nature, is an ancient system that has not been well studied in insects. This study aims to investigate the key components of the cholinergic system and to identify the non-neuronal acetylcholine (ACh)-producing cells and the acting sites of ACh in the Malpighian tubules (MTs) of Mythimna separata. We found that non-neuronal ACh in MTs is synthesized by carnitine acetyltransferase (CarAT), rather than choline acetyltransferase (ChAT), as confirmed by using enzyme inhibitors and high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS). Fluorescence in situ hybridization revealed the presence of CarAT mRNA within MTs, specifically localized in the principal cells. Immunohistochemistry showed strong staining for A-mAChR, a muscarinic acetylcholine receptor, in the principal cells. Pharmacological analysis further demonstrated that ACh acts through A-mAChR in the principal cells to increase the intracellular Ca2+ concentration. These findings provide compelling evidence for the existence of a non-neuronal cholinergic system in the MTs of M. separata, and the principal cells play a crucial role in ACh synthesis via CarAT.

Bridging the Mind and Gut: Uncovering the Intricacies of Neurotransmitters, Neuropeptides, and their Influence on Neuropsychiatric Disorders

BACKGROUND

The gut-brain axis (GBA) is a bidirectional signaling channel that facilitates communication between the gastrointestinal tract and the brain. Recent research on the gut-brain axis demonstrates that this connection enables the brain to influence gut function, which in turn influences the brain and its cognitive functioning. It is well established that malfunctioning of this axis adversely affects both systems' ability to operate effectively.

OBJECTIVE

Dysfunctions in the GBA have been associated with disorders of gut motility and permeability, intestinal inflammation, indigestion, constipation, diarrhea, IBS, and IBD, as well as neuropsychiatric and neurodegenerative disorders like depression, anxiety, schizophrenia, autism, Alzheimer's, and Parkinson's disease. Multiple research initiatives have shown that the gut microbiota, in particular, plays a crucial role in the GBA by participating in the regulation of a number of key neurochemicals that are known to have significant effects on the mental and physical well-being of an individual.

METHODS

Several studies have investigated the relationship between neuropsychiatric disorders and imbalances or disturbances in the metabolism of neurochemicals, often leading to concomitant gastrointestinal issues and modifications in gut flora composition. The interaction between neurological diseases and gut microbiota has been a focal point within this research. The novel therapeutic interventions in neuropsychiatric conditions involving interventions such as probiotics, prebiotics, and dietary modifications are outlined in this review.

RESULTS

The findings of multiple studies carried out on mice show that modulating and monitoring gut microbiota can help treat symptoms of such diseases, which raises the possibility of the use of probiotics, prebiotics, and even dietary changes as part of a new treatment strategy for neuropsychiatric disorders and their symptoms.

CONCLUSION

The bidirectional communication between the gut and the brain through the gut-brain axis has revealed profound implications for both gastrointestinal and neurological health. Malfunctions in this axis have been connected to a range of disorders affecting gut function as well as cognitive and neuropsychiatric well-being. The emerging understanding of the role of gut microbiota in regulating key neurochemicals opens up possibilities for novel treatment approaches for conditions like depression, anxiety, and neurodegenerative diseases.

Acetylcholine and metacognition during sleep

Acetylcholine is a neurotransmitter and neuromodulator involved in a variety of cognitive functions. Additionally, acetylcholine is involved in the regulation of REM sleep: cholinergic neurons in the brainstem and basal forebrain project to and innervate wide areas of the cerebral cortex, and reciprocally interact with other neuromodulatory systems, to produce the sleep-wake cycle and different sleep stages. Consciousness and cognition vary considerably across and within sleep stages, with metacognitive capacity being strikingly reduced even during aesthetically and emotionally rich dream experiences. A notable exception is the phenomenon of lucid dreaming-a rare state whereby waking levels of metacognitive awareness are restored during sleep-resulting in individuals becoming aware of the fact that they are dreaming. The role of neurotransmitters in these fluctuations of consciousness and cognition during sleep is still poorly understood. While recent studies using acetylcholinesterase inhibitors suggest a potential role of acetylcholine in the occurrence of lucid dreaming, the underlying mechanisms by which this effect is produced remains un-modelled and unknown; with the causal link between cholinergic mechanisms and upstream psychological states being complex and elusive. Several theories and approaches targeting the association between acetylcholine and metacognition during wakefulness and sleep are highlighted in this review, moving through microscopic, mesoscopic and macroscopic levels of analysis to detail this phenomenon at several organisational scales. Several exploratory hypotheses will be developed to guide future research towards fully articulating how metacognition is affected by activity at the acetylcholine receptor.

Exploring the Evolvability of Plant Specialized Metabolism: Uniqueness Out Of Uniformity and Uniqueness Behind Uniformity

The huge structural diversity exhibited by plant specialized metabolites has primarily been considered to result from the catalytic specificity of their biosynthetic enzymes. Accordingly, enzyme gene multiplication and functional differentiation through spontaneous mutations have been established as the molecular mechanisms that drive metabolic evolution. Nevertheless, how plants have assembled and maintained such metabolic enzyme genes and the typical clusters that are observed in plant genomes, as well as why identical specialized metabolites often exist in phylogenetically remote lineages, is currently only poorly explained by a concept known as convergent evolution. Here, we compile recent knowledge on the co-presence of metabolic modules that are common in the plant kingdom but have evolved under specific historical and contextual constraints defined by the physicochemical properties of each plant specialized metabolite and the genetic presets of the biosynthetic genes. Furthermore, we discuss a common manner to generate uncommon metabolites (uniqueness out of uniformity) and an uncommon manner to generate common metabolites (uniqueness behind uniformity). This review describes the emerging aspects of the evolvability of plant specialized metabolism that underlie the vast structural diversity of plant specialized metabolites in nature.

Gut liver brain axis in diseases: the implications for therapeutic interventions

Gut-liver-brain axis is a three-way highway of information interaction system among the gastrointestinal tract, liver, and nervous systems. In the past few decades, breakthrough progress has been made in the gut liver brain axis, mainly through understanding its formation mechanism and increasing treatment strategies. In this review, we discuss various complex networks including barrier permeability, gut hormones, gut microbial metabolites, vagus nerve, neurotransmitters, immunity, brain toxic metabolites, β-amyloid (Aβ) metabolism, and epigenetic regulation in the gut-liver-brain axis. Some therapies containing antibiotics, probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT), polyphenols, low FODMAP diet and nanotechnology application regulate the gut liver brain axis. Besides, some special treatments targeting gut-liver axis include farnesoid X receptor (FXR) agonists, takeda G protein-coupled receptor 5 (TGR5) agonists, glucagon-like peptide-1 (GLP-1) receptor antagonists and fibroblast growth factor 19 (FGF19) analogs. Targeting gut-brain axis embraces cognitive behavioral therapy (CBT), antidepressants and tryptophan metabolism-related therapies. Targeting liver-brain axis contains epigenetic regulation and Aβ metabolism-related therapies. In the future, a better understanding of gut-liver-brain axis interactions will promote the development of novel preventative strategies and the discovery of precise therapeutic targets in multiple diseases.

Gut Microbiota in Ischemic Stroke: Role of Gut Bacteria-Derived Metabolites

Ischemic stroke (IS) remains a leading cause of death and long-term disability globally. Several mechanisms including glutamate excitotoxicity, calcium overload, neuroinflammation, oxidative stress, mitochondrial damage, and apoptosis are known to be involved in the pathogenesis of IS, but the underlying pathophysiology mechanisms of IS are not fully clarified. During the past decade, gut microbiota were recognized as a key regulator to affect the health of the host either directly or via their metabolites. Recent studies indicate that gut bacterial dysbiosis is closely related to hypertension, diabetes, obesity, dyslipidemia, and metabolic syndrome, which are the main risk factors for cardiovascular diseases. Increasing evidence indicates that IS can lead to perturbation in gut microbiota and increased permeability of the gut mucosa, known as "leaky gut," resulting in endotoxemia and bacterial translocation. In turn, gut dysbiosis and impaired intestinal permeability can alter gut bacterial metabolite signaling profile from the gut to the brain. Microbiota-derived products and metabolites, such as short-chain fatty acids (SCFAs), bile acids (BAs), trimethylamine N-oxide (TMAO), lipopolysaccharides (LPS), and phenylacetylglutamine (PAGln) can exert beneficial or detrimental effects on various extraintestinal organs, including the brain, liver, and heart. These metabolites have been increasingly acknowledged as biomarkers and mediators of IS. However, the specific role of the gut bacterial metabolites in the context of stroke remains incompletely understood. In-depth studies on these products and metabolites may provide new insight for the development of novel therapeutics for IS.

Understanding the Gut-Brain Axis and Its Therapeutic Implications for Neurodegenerative Disorders

The gut-brain axis (GBA) is a complex bidirectional communication network connecting the gut and brain. It involves neural, immune, and endocrine communication pathways between the gastrointestinal (GI) tract and the central nervous system (CNS). Perturbations of the GBA have been reported in many neurodegenerative disorders (NDDs), such as Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS), among others, suggesting a possible role in disease pathogenesis. The gut microbiota is a pivotal component of the GBA, and alterations in its composition, known as gut dysbiosis, have been associated with GBA dysfunction and neurodegeneration. The gut microbiota might influence the homeostasis of the CNS by modulating the immune system and, more directly, regulating the production of molecules and metabolites that influence the nervous and endocrine systems, making it a potential therapeutic target. Preclinical trials manipulating microbial composition through dietary intervention, probiotic and prebiotic supplementation, and fecal microbial transplantation (FMT) have provided promising outcomes. However, its clear mechanism is not well understood, and the results are not always consistent. Here, we provide an overview of the major components and communication pathways of the GBA, as well as therapeutic approaches targeting the GBA to ameliorate NDDs.

Unveiling the role of gut-brain axis in regulating neurodegenerative diseases: A comprehensive review

Emerging evidence have shown the importance of gut microbiota in regulating brain functions. The diverse molecular mechanisms involved in cross-talk between gut and brain provide insight into importance of this communication in maintenance of brain homeostasis. It has also been observed that disturbed gut microbiota contributes to neurological diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis and aging. Recently, gut microbiome-derived exosomes have also been reported to play an essential role in the development and progression of neurodegenerative diseases and could thereby act as a therapeutic target. Further, pharmacological interventions including antibiotics, prebiotics and probiotics can influence gut microbiome-mediated management of neurological diseases. However, extensive research is warranted to better comprehend this interconnection in maintenance of brain homeostasis and its implication in neurological diseases. Thus, the present review is aimed to provide a detailed understanding of gut-brain axis followed by possibilities to target the gut microbiome for improving neurological health.

Changes in the Acetylcholinesterase Enzymatic Activity in Tumor Development and Progression

Acetylcholinesterase is a well-known protein because of the relevance of its enzymatic activity in the hydrolysis of acetylcholine in nerve transmission. In addition to the catalytic action, it exerts non-catalytic functions; one is associated with apoptosis, in which acetylcholinesterase could significantly impact the survival and aggressiveness observed in cancer. The participation of AChE as part of the apoptosome could explain the role in tumors, since a lower AChE content would increase cell survival due to poor apoptosome assembly. Likewise, the high Ach content caused by the reduction in enzymatic activity could induce cell survival mediated by the overactivation of acetylcholine receptors (AChR) that activate anti-apoptotic pathways. On the other hand, in tumors in which high enzymatic activity has been observed, AChE could be playing a different role in the aggressiveness of cancer; in this review, we propose that AChE could have a pro-inflammatory role, since the high enzyme content would cause a decrease in ACh, which has also been shown to have anti-inflammatory properties, as discussed in this review. In this review, we analyze the changes that the enzyme could display in different tumors and consider the different levels of regulation that the acetylcholinesterase undergoes in the control of epigenetic changes in the mRNA expression and changes in the enzymatic activity and its molecular forms. We focused on explaining the relationship between acetylcholinesterase expression and its activity in the biology of various tumors. We present up-to-date knowledge regarding this fascinating enzyme that is positioned as a remarkable target for cancer treatment.

Epithelial Ca2+ waves triggered by enteric neurons heal the gut

A fundamental and unresolved question in regenerative biology is how tissues return to homeostasis after injury. Answering this question is essential for understanding the etiology of chronic disorders such as inflammatory bowel diseases and cancer. We used the Drosophila midgut to investigate this question and discovered that during regeneration a subpopulation of cholinergic enteric neurons triggers Ca2+ currents among enterocytes to promote return of the epithelium to homeostasis. Specifically, we found that down-regulation of the cholinergic enzyme Acetylcholinesterase in the epithelium enables acetylcholine from defined enteric neurons, referred as ARCENs, to activate nicotinic receptors in enterocytes found near ARCEN-innervations. This activation triggers high Ca2+ influx that spreads in the epithelium through Inx2/Inx7 gap junctions promoting enterocyte maturation followed by reduction of proliferation and inflammation. Disrupting this process causes chronic injury consisting of ion imbalance, Yki activation and increase of inflammatory cytokines together with hyperplasia, reminiscent of inflammatory bowel diseases. Altogether, we found that during gut regeneration the conserved cholinergic pathway facilitates epithelial Ca2+ waves that heal the intestinal epithelium. Our findings demonstrate nerve- and bioelectric-dependent intestinal regeneration which advance the current understanding of how a tissue returns to its homeostatic state after injury and could ultimately help existing therapeutics.

The neuroprotective effect of traditional Chinese medicinal plants-A critical review

Neurodegenerative and neuropsychiatric diseases are increasingly affecting individuals' quality of life, thus increasing their cost to social and health systems. These diseases have overlapping mechanisms, such as oxidative stress, protein aggregation, neuroinflammation, neurotransmission impairment, mitochondrial dysfunction, and excitotoxicity. Currently, there is no cure for neurodegenerative diseases, and the available therapies have adverse effects and low efficacy. For neuropsychiatric disorders, such as depression, the current therapies are not adequate to one-third of the patients, the so-called treatment-resistant patients. So, searching for new treatments is fundamental. Medicinal plants appear as a strong alternative and complement towards new treatment protocols, as they have been used for health purposes for thousands of years. Thus, the main goal of this review is to revisit the neuroprotective potential of some of the most predominant medicinal plants (and one fungus) used in traditional Chinese medicine (TCM), focusing on their proven mechanisms of action and their chemical compositions, to give clues on how they can be useful against neurodegeneration progression.

The brain-gut-microbiota axis in the treatment of neurologic and psychiatric disorders

The human gut microbiota is a complex ecosystem made of trillions of microorganisms. The composition can be affected by diet, metabolism, age, geography, stress, seasons, temperature, sleep, and medications. The increasing evidence about the existence of a close and bi-directional correlation between the gut microbiota and the brain indicates that intestinal imbalance may play a vital role in the development, function, and disorders of the central nervous system. The mechanisms of interaction between the gut-microbiota on neuronal activity are widely discussed. Several potential pathways are involved with the brain-gut-microbiota axis, including the vagus nerve, endocrine, immune, and biochemical pathways. Gut dysbiosis has been linked to neurological disorders in different ways that involve activation of the hypothalamic-pituitary-adrenal axis, imbalance in neurotransmitter release, systemic inflammation, and increase in the permeability of the intestinal and the blood-brain barrier. Mental and neurological diseases have become more prevalent during the coronavirus disease 2019pandemic and are an essential issue in public health globally. Understanding the importance of diagnosing, preventing, and treating dysbiosis is critical because gut microbial imbalance is a significant risk factor for these disorders. This review summarizes evidence demonstrating the influence of gut dysbiosis on mental and neurological disorders.

Understanding the ADHD-Gut Axis by Metabolic Network Analysis

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder diagnosed with hyperactivity, impulsivity, and a lack of attention inconsistent with the patient's development level. The fact that people with ADHD frequently experience gastrointestinal (GI) dysfunction highlights the possibility that the gut microbiome may play a role in this condition. The proposed research aims to determine a biomarker for ADHD by reconstructing a model of the gut-microbial community. Genome-scale metabolic models (GEM) considering the relationship between gene-protein-reaction associations are used to simulate metabolic activities in organisms of gut. The production rates of dopamine and serotonin precursors and the key short chain fatty acids which affect the health status are determined under three diets (Western, Atkins', Vegan) and compared with those of healthy people. Elasticities are calculated to understand the sensitivity of exchange fluxes to changes in diet and bacterial abundance at the species level. The presence of Bacillota (genus Coprococcus and Subdoligranulum), Actinobacteria (genus Collinsella), Bacteroidetes (genus Bacteroides), and Bacteroidota (genus Alistipes) may be possible gut microbiota indicators of ADHD. This type of modeling approach taking microbial genome-environment interactions into account helps us understand the gastrointestinal mechanisms behind ADHD, and establish a path to improve the quality of life of ADHD patients.

Evaluation of the Antihypertensive Activity of Eggplant Acetylcholine and γ-Aminobutyric Acid in Spontaneously Hypertensive Rats

Daily consumption of eggplant powder containing 2.3 mg acetylcholine (ACh) is known to alleviate hypertension and improve mental status. However, eggplant powder used in clinical trials also contains the antihypertensive compound γ-aminobutyric acid (GABA). Although our previous study indicated that the main antihypertensive compound in eggplant is ACh, given that GABA amounts in eggplant do not reach the effective dosage, the effects of GABA on the antihypertensive effect of eggplant remain unclear. It is necessary to establish whether there is a synergistic effect between GABA and ACh and whether GABA in eggplant exerts antihypertensive effects. Consequently, here we sought to evaluate the effects of GABA on the antihypertensive effects of eggplant. We used a probability sum (q) test to investigate the combined effects of ACh and GABA and prepared eggplant powder with very low ACh content for oral administration in animals. ACh and GABA exhibited additive effects but the GABA content in eggplants was not sufficient to promote a hypotensive effect. In conclusion, ACh is the main component associated with the antihypertensive effects of eggplant but GABA within eggplants has a minimal effect in this regard. Thus, compared with GABA, ACh could be a more effective functional food constituent for lowering blood pressure.

Influence of the gut microbiota on satiety signaling

Recent studies show a link between the gut microbiota and the regulation of satiety and energy intake, processes that contribute to the development and pathophysiology of metabolic diseases. However, this link is predominantly established in animal and in vitro studies, whereas human intervention studies are scarce. In this review we focus on recent evidence linking satiety and the gut microbiome, with specific emphasis on gut microbial short-chain fatty acids (SCFAs). Based on a systematic search we provide an overview of human studies linking the intake of prebiotics with gut microbial alterations and satiety signaling. Our outcomes highlight the importance of in-depth examination of the gut microbiota in relation to satiety and provide insights into recent and future studies in this field.

Role of neuronal and non-neuronal acetylcholine signaling in Drosophila humoral immunity

Acetylcholine (ACh) is one the major neurotransmitters in insects, whose role in mediating synaptic interactions between neurons in the central nervous system is well characterized. It also plays largely unexplored regulatory functions in non-neuronal tissues. Here we demonstrate that ACh signaling is involved in the modulation of the innate immune response of Drosophila melanogaster. Knockdown of ACh synthesis or ACh vesicular transport in neurons reduced the activation of drosomycin (drs), a gene encoding an antimicrobial peptide, in adult flies infected with a Gram-positive bacterium. drs transcription was similarly affected in Drosophila α7 nicotinic acetylcholine receptor, nAChRalpha7 (Dα7) mutants, as well as in flies expressing in the nervous system a dominant negative form (Dα7^DN) of this specific receptor subunit. Interestingly, Dα7^DN elicited a comparable response when it was expressed in non-neuronal tissues and even when it was specifically produced in the hemocytes. Consistently, full activation of the drs gene required Dα7 expression in these cells. Moreover, knockdown of ACh synthesis in non-neuronal cells affected drs expression. Overall, these findings uncover neural and non-neural cholinergic signals that modulate insect immune defenses and shed light on the role of hemocytes in the regulation of the humoral immune response.

Interlink between the gut microbiota and inflammation in the context of oxidative stress in Alzheimer's disease progression

The microbiota-gut-brain axis is an important pathway of communication and may dynamically contribute to Alzheimer's disease (AD) pathogenesis. Pathological commensal gut microbiota alterations, termed as dysbiosis, can influence intestinal permeability and break the blood-brain barrier which may trigger AD pathogenesis via redox signaling, neuronal, immune, and metabolic pathways. Dysbiosis increases the oxidative stress. Oxidants affect the innate immune system through recognizing microbial-derived pathogens by Toll-like receptors and initiating the inflammatory process. Most of the gut microbiome research work highlights the relationship between the gut microbiota and AD, but the contributory connection between precise bacteria and brain dysfunction in AD pathology cannot be fully demonstrated. Here, we summarize the current information of the fundamental connections between oxidative stress, inflammation, and gut dysbiosis in AD. This review emphasizes on the involvement of gut microbiota in the regulation of oxidative stress, inflammation, immune responses including central and peripheral cross-talk. It provides insights for novel preventative and therapeutic approaches in AD.

Comparative transcriptome analysis reveals the non-neuronal cholinergic system in the ovary of the oriental armyworm, Mythimna separata Walker (Lepidoptera: Noctuidae)

BACKGROUND

Acetylcholine (ACh), as a classical neurotransmitter, plays great roles in the nervous system. There is increasing evidence of its non-neuronal roles in regulating basic cell functions in vertebrates. However, knowledge about the non-neuronal cholinergic system in insects is scarce.

RESULTS

A comparative transcriptome analysis was performed to investigate differences in the key molecular components of the cholinergic system between the head and ovary. The results showed that expression levels of most cholinergic system-related genes were higher in the head than in the ovary, and some cholinergic components were absent in the ovary. ACh contents ranged from 0.1 to 1.3 μg mg^-1 of wet weight during the development of the ovary, and weak acetylcholinesterase activity was also detected. Moreover, the ovary has a capacity for ACh synthesis. Bromoacetylcarnitine (BrACar), a specific carnitine acetyltransferase (CarAT) inhibitor, greatly inhibits ACh synthesis by 83.83% in ovary homogenates, but bromoacetylcholine (BrACh), a specific choline acetyltransferase (ChAT) inhibitor, has no effect on ACh synthesis in the ovary. These findings indicate that non-neuronal ACh in the ovary is only catalyzed by CarAT.

CONCLUSION

This study reveals the existence of the non-neuronal cholinergic system in the ovary of M. separata, whose synthesis and release mechanisms are different from those of the head. These results provide novel insights into the non-neuronal cholinergic system in insects, and will be valuable in the discovery of new target genes and the future development of green pest control. © 2022 Society of Chemical Industry.

Significance of an Electrochemical Sensor and Nanocomposites: Toward the Electrocatalytic Detection of Neurotransmitters and Their Importance within the Physiological System

A prominent neurotransmitter (NT), dopamine (DA), is a chemical messenger that transmits signals between one neuron to the next to pass on a signal to and from the central nervous system (CNS). The imbalanced concentration of DA may cause numerous neurological sicknesses and syndromes, for example, Parkinson's disease (PD) and schizophrenia. There are many types of NTs in the brain, including epinephrine, norepinephrine (NE), serotonin, and glutamate. Electrochemical sensors have offered a creative direction to biomedical analysis and testing. Researches are in progress to improve the performance of sensors and develop new protocols for sensor design. This review article focuses on the area of sensor growth to discover the applicability of polymers and metallic particles and composite materials as tools in electrochemical sensor surface incorporation. Electrochemical sensors have attracted the attention of researchers as they possess high sensitivity, quick reaction rate, good controllability, and instantaneous detection. Efficient complex materials provide considerable benefits for biological detection as they have exclusive chemical and physical properties. Due to distinctive electrocatalytic characteristics, metallic nanoparticles add fascinating traits to materials that depend on the material's morphology and size. Herein, we have collected much information on NTs and their importance within the physiological system. Furthermore, the electrochemical sensors and corresponding techniques (such as voltammetric, amperometry, impedance, and chronoamperometry) and the different types of electrodes' roles in the analysis of NTs are discussed. Furthermore, other methods for detecting NTs include optical and microdialysis methods. Finally, we show the advantages and disadvantages of different techniques and conclude remarks with future perspectives.

LiGIoNs: A computational method for the detection and classification of ligand-gated ion channels

Ligand-Gated Ion Channels (LGICs) is one of the largest groups of transmembrane proteins. Due to their major role in synaptic transmission, both in the nervous system and the somatic neuromuscular junction, LGICs present attractive therapeutic targets. During the last few years, several computational methods for the detection of LGICs have been developed. These methods are based on machine learning approaches utilizing features extracted solely from the amino acid composition. Here we report the development of LiGIoNs, a profile Hidden Markov Model (pHMM) method for the prediction and ligand-based classification of LGICs. The method consists of a library of 10 pHMMs, one per LGIC subfamily, built from the alignment of representative LGIC sequences. In addition, 14 Pfam pHMMs are used to further annotate and classify unknown protein sequences into one of the 10 LGIC subfamilies. Evaluation of the method showed that it outperforms existing methods in the detection of LGICs. On top of that, LiGIoNs is the only currently available method that classifies LGICs into subfamilies. The method is available online at http://bioinformatics.biol.uoa.gr/ligions/.

Gut microbiota: Linking nutrition and perinatal depression

Perinatal depression is a mood disorder that is reported in women during pregnancy (prenatal) and after childbirth (postnatal). The onset of perinatal depression is associated with changes in reproductive hormones, stress hormones and neurosteroids. These chemical compounds can be modulated by the gut microbiota, which may affect maternal mental health during the perinatal period via the gut-brain-axis. Recent studies suggest that nutritional and dietary interventions (vitamin D, ω-3 fatty acids, iron, and fiber) effectively prevent or mitigate maternal depression and anxiety, but their efficacy is confounded by various factors, including the gut microbiota. Probiotics are efficacious in maintaining microbiota homeostasis, and thus, have the potential to modulate the development of perinatal mood disorders, despite no evidence in human. Therefore, clinical trials are warranted to investigate the role of probiotic supplementation in perinatal depression and behavioral changes. This article reviews the interplay between nutrition, gut microbiota and mood and cognition, and the evidence suggesting that probiotics affect the onset and development of perinatal depression.

Microbial-derived metabolites as a risk factor of age-related cognitive decline and dementia

A consequence of our progressively ageing global population is the increasing prevalence of worldwide age-related cognitive decline and dementia. In the absence of effective therapeutic interventions, identifying risk factors associated with cognitive decline becomes increasingly vital. Novel perspectives suggest that a dynamic bidirectional communication system between the gut, its microbiome, and the central nervous system, commonly referred to as the microbiota-gut-brain axis, may be a contributing factor for cognitive health and disease. However, the exact mechanisms remain undefined. Microbial-derived metabolites produced in the gut can cross the intestinal epithelial barrier, enter systemic circulation and trigger physiological responses both directly and indirectly affecting the central nervous system and its functions. Dysregulation of this system (i.e., dysbiosis) can modulate cytotoxic metabolite production, promote neuroinflammation and negatively impact cognition. In this review, we explore critical connections between microbial-derived metabolites (secondary bile acids, trimethylamine-N-oxide (TMAO), tryptophan derivatives and others) and their influence upon cognitive function and neurodegenerative disorders, with a particular interest in their less-explored role as risk factors of cognitive decline.

Non-neuronal Cholinergic Muscarinic Acetylcholine Receptors in the Regulation of Immune Function

Immune cells such as T and B cells, monocytes and macrophages all express most of the cholinergic components of the nervous system, including acetylcholine (ACh), choline acetyltransferase (ChAT), high affinity choline transporter, muscarinic and nicotinic ACh receptors (mAChRs and nAChRs, respectively), and acetylcholinesterase (AChE). Because of its efficient cleavage by AChE, ACh synthesized and released from immune cells acts only locally in an autocrine and/or paracrine fashion at mAChRs and nAChRs on themselves and other immune cells located in close proximity, leading to modification of immune function. Immune cells generally express all five mAChR subtypes (M₁-M₅) and neuron type nAChR subunits α2-α7, α9, α10, β2-β4. The expression pattern and levels of mAChR subtypes and nAChR subunits vary depending on the tissue involved and its immunological status. Immunological activation of T cells via T-cell receptor-mediated pathways and cell adhesion molecules upregulates ChAT expression, which facilitates the synthesis and release of ACh. At present, α7 nAChRs expressed in macrophages are receiving much attention because they play a central role in anti-inflammatory cholinergic pathways. However, it now appears that through modification of cytokine synthesis, G_q/11-coupled mAChRs play a prominent role in regulation of T cell proliferation and differentiation and B cell immunoglobulin class switching. It is anticipated that greater understanding of G_q/11-coupled mAChRs on immune cells will provide an opportunity to develop new and effective treatments for immunological disorders.

ACTH(6-9)-Pro-Gly-Pro ameliorates anxiety-like and depressive-like behaviour and gut mucosal microbiota composition in rats under conditions of chronic restraint stress

The effects of the peptide ACTH(6-9)-Pro-Gly-Pro at doses of 5; 50; 500 μg/kg on the Wistar rats' behaviour and gut mucosal microbiota composition under conditions of chronic immobilization stress (CRS) were studied. CRS increased anxiety-like and depressive-like behaviour, disturbances in locomotor activity and gut dysbiosis. Administration of ACTH(6-9)-Pro-Gly-Pro showed many phenotypic results. Peptide demonstrated anti-depressant activity at doses of 5 and 500 μg/kg by a decrease in the total immobile time in the FST. ACTH(6-9)-Pro-Gly-Pro administered at a dose of 50 μg/kg resulted in an anxiolytic effect which is shown by an increase in the time in the open arms of EPM (p < 0.05) and a decrease in the time in the closed arms (p < 0.05). Moreover, the peptide led to a decrease in alpha- and beta-diversity of the gut microbiota (p < 0.01). Correlation and linear regression analysis demonstrated central mechanisms of ACTH(6-9)-Pro-Gly-Pro anxiolytic activity and both central and peripheral ones in an anti-depressant effect. In this way, peptide ACTH(6-9)-Pro-Gly-Pro could prevent the development of behavioural disturbances and gut dysbiosis caused by chronic restraint stress.

Marine Sponge Endosymbionts: Structural and Functional Specificity of the Microbiome within Euryspongia arenaria Cells

Sponge microbiomes are typically profiled by analyzing the community DNA of whole tissues, which does not distinguish the taxa residing within sponge cells from extracellular microbes. To uncover the endosymbiotic microbiome, we separated the sponge cells to enrich the intracellular microbes. The intracellular bacterial community of sponge Euryspongia arenaria was initially assessed by amplicon sequencing, which indicated that it hosts three unique phyla not found in the extracellular and bulk tissue microbiomes. These three phyla account for 66% of the taxonomically known genera in the intracellular microbiome. The shotgun metagenomic analysis extended the taxonomic coverage to viruses and eukaryotes, revealing the most abundant signature taxa specific to the intracellular microbiome. Functional KEGG pathway annotation demonstrated that the endosymbiotic microbiome hosted the greatest number of unique gene orthologs. The pathway profiles distinguished the intra- and extracellular microbiomes from the tissue and seawater microbiomes. Carbohydrate-active enzyme analysis further discriminated each microbiome based on their representative and dominant enzyme families. One pathway involved in digestion system and family esterase had a consistently higher level in intracellular microbiome and could statistically differentiate the intracellular microbiome from the others, suggesting that triacylglycerol lipases could be the key functional component peculiar to the endosymbionts. The identified higher abundance of lipase-related eggNOG categories further supported the lipid-hydrolyzing metabolism of endosymbiotic microbiota. Pseudomonas members, reported as lipase-producing bacteria, were only in the endosymbiotic microbiome, meanwhile Pseudomonas also showed a greater abundance intracellularly. Our study aided a comprehensive sponge microbiome that demonstrated the taxonomic and functional specificity of endosymbiotic microbiota.

IMPORTANCE Sponges host abundant microbial symbionts that can produce an impressive number of novel bioactive metabolites. However, knowledge on intracellular (endosymbiotic) microbiota is scarce. We characterize the composition and function of the endosymbiotic microbiome by separation of sponge cells and enrichment of intracellular microbes. We uncover a noteworthy number of taxa exclusively in the endosymbiotic microbiome. We unlock the unique pathways and enzymes of endosymbiotic taxa. This study achieves a more comprehensive sponge microbial community profile, which demonstrates the structural and functional specificity of the endosymbiotic microbiome. Our findings not only open the possibility to reveal the low abundant and the likely missed microbiota when directly sequencing the sponge bulk tissues, but also warrant future in-depth exploration within single sponge cells.

Non-Neuronal Transmitter Systems in Bacteria, Non-Nervous Eukaryotes, and Invertebrate Embryos

In 1921, Otto Loewi published his report that ushered in the era of chemical transmission of biological signals. January 2021 marked the 90th anniversary of the birth of Professor Gennady A. Buznikov, who was the first to study the functions of transmitters in embryogenesis. A year earlier it was 60 years since his first publication in this field. These data are a venerable occasion for a review of current knowledge on the mechanisms related to classical transmitters such as 5-hydroxytryptamine, acetylcholine, catecholamines, etc., in animals lacking neural elements and prenervous invertebrate embryos.

Drug pollution & Sustainable Development Goals

The United Nations set "The 2030 Agenda for Sustainable Development," which includes the Sustainable Development Goals (SDGs), a collection of 17 global goals designed to be a "blueprint to achieve a better and more sustainable future for all". Although only mentioned in one of the seventeen goals (goal 3), we argue that drugs in general, and growing drug pollution in particular, affects the SDGs in deeper, not readily apparent ways. So far, the emerging problem of drug pollution has not been sufficiently addressed. Here, we outline and discuss how drug pollution can affect SDGs and even threaten their achievement.

Gene expression profiles of the muscarinic acetylcholine receptors in brain regions relating to filial imprinting of newly-hatched domestic chicks

Muscarinic acetylcholine receptors (mAChRs) in the central nervous system play an important role in regulating complex functions such as learning, memory, and selective attention. Five subtypes of the mAChRs (M₁-M₅) have been identified in mammals, and are classified into two subfamilies: excitatory (M₁, M₃, and M₅) and inhibitory (M₂ and M₄) subfamilies. Filial imprinting of domestic chicks is a useful model in the laboratory to investigate the mechanisms of memory formation in early learning. We recently found that mAChRs in the intermediate medial mesopallium (IMM) are involved in the memory formation of imprinting. However, expression profiles of each mAChR subtype in the brain regions including the IMM remain unexplored. Here we show the unique gene expression of each mAChR subtype in the pallial regions involved in imprinting. In terms of the excitatory mAChRs, M₅ was expressed in the IMM region and other parts of the pallium, whereas M₃ was less expressed in the IMM but highly expressed in the hyperpallium and nidopallium. Regarding the inhibitory mAChRs, M₂ was sparsely distributed but clearly in some cells throughout the pallial regions. M₄ was highly expressed in the IMM region and other parts of the pallium. These expression profiles can be used as a basis for understanding cholinergic modulation in the memory formation of imprinting and other learning processes in birds, and compared to those of mammals.

Environmental pollution with psychiatric drugs

Among all contaminants of emerging interest, drugs are the ones that give rise to the greatest concern. Any of the multiple stages of the drug's life cycle (production, consumption and waste management) is a possible entry point to the different environmental matrices. Psychiatric drugs have received special attention because of two reasons. First, their use is increasing. Second, many of them act on phylogenetically highly conserved neuroendocrine systems, so they have the potential to affect many non-target organisms. Currently, wastewater is considered the most important source of drugs to the environment. Furthermore, the currently available wastewater treatment plants are not specifically prepared to remove drugs, so they reach practically all environmental matrices, even tap water. As drugs are designed to produce pharmacological effects at low concentrations, they are capable of producing ecotoxicological effects on microorganisms, flora and fauna, even on human health. It has also been observed that certain antidepressants and antipsychotics can bioaccumulate along the food chain. Drug pollution is a complicated and diffuse problem characterized by scientific uncertainties, a large number of stakeholders with different values and interests, and enormous complexity. Possible solutions consist on acting at source, using medicines more rationally, eco-prescribing or prescribing greener drugs, designing pharmaceuticals that are more readily biodegraded, educating both health professionals and citizens, and improving coordination and collaboration between environmental and healthcare sciences. Besides, end of pipe measures like improving or developing new purification systems (biological, physical, chemical, combination) that eliminate these residues efficiently and at a sustainable cost should be a priority. Here, we describe and discuss the main aspects of drug pollution, highlighting the specific issues of psychiatric drugs.

Regulation of Neurotransmitters by the Gut Microbiota and Effects on Cognition in Neurological Disorders

Emerging evidence indicates that gut microbiota is important in the regulation of brain activity and cognitive functions. Microbes mediate communication among the metabolic, peripheral immune, and central nervous systems via the microbiota–gut–brain axis. However, it is not well understood how the gut microbiome and neurons in the brain mutually interact or how these interactions affect normal brain functioning and cognition. We summarize the mechanisms whereby the gut microbiota regulate the production, transportation, and functioning of neurotransmitters. We also discuss how microbiome dysbiosis affects cognitive function, especially in neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease.

Expression of Cholinergic Markers and Characterization of Splice Variants during Ontogenesis of Rat Dorsal Root Ganglia Neurons

Dorsal root ganglia (DRG) neurons synthesize acetylcholine (ACh), in addition to their peptidergic nature. They also release ACh and are cholinoceptive, as they express cholinergic receptors. During gangliogenesis, ACh plays an important role in neuronal differentiation, modulating neuritic outgrowth and neurospecific gene expression. Starting from these data, we studied the expression of choline acetyltransferase (ChAT) and vesicular ACh transporter (VAChT) expression in rat DRG neurons. ChAT and VAChT genes are arranged in a “cholinergic locus”, and several splice variants have been described. Using selective primers, we characterized splice variants of these cholinergic markers, demonstrating that rat DRGs express R1, R2, M, and N variants for ChAT and V1, V2, R1, and R2 splice variants for VAChT. Moreover, by RT-PCR analysis, we observed a progressive decrease in ChAT and VAChT transcripts from the late embryonic developmental stage (E18) to postnatal P2 and P15 and in the adult DRG. Interestingly, Western blot analyses and activity assays demonstrated that ChAT levels significantly increased during DRG ontogenesis. The modulated expression of different ChAT and VAChT splice variants during development suggests a possible differential regulation of cholinergic marker expression in sensory neurons and confirms multiple roles for ACh in DRG neurons, both in the embryo stage and postnatally.

Antipsychotics as environmental pollutants: An underrated threat?

The heterogeneous class of what we nowadays call antipsychotics was born almost 70 years ago with the serendipitous discovery of chlorpromazine. Their utilization is constantly growing because they are used to treat a diverse group of diseases and patients across all age groups: schizophrenia, bipolar disease, depression, autism, attention deficit hyperactivity disorder, behavioural and psychological symptoms in dementia, among others. They possess a complex pharmacological profile, acting on multiple receptors: dopaminergic, serotoninergic, histaminergic, adrenergic, and cholinergic, leading scientists to call them "agents with rich pharmacology" or "dirty drugs". Serotonin, dopamine, acetylcholine, noradrenaline, histamine and their respective receptors are evolutionary ancient compounds, and as such, are found in many different living beings in the environment. Antipsychotics do not disappear once excreted by patient's urine or faeces and are transported to wastewater treatment plants. But as these plant's technology is not designed to eliminate drugs and their metabolites, a variable proportion of the administered dose ends up in the environment, where they have been found in almost every matrix: municipal wastewater, hospital sewage, rivers, lakes, sea and even drinking water. We believe that reported concentrations found in the environment might be high enough to exert significant effect to aquatic wildlife. Besides, recent studies suggest antipsychotics, among others, are very likely bioaccumulating through the web food. Crucially, psychotropics may provoke behavioural changes affecting populations' dynamics at lower concentrations. We believe that so far, antipsychotics have not received the attention they deserve with regards to drug pollution, and that their role as environmental pollutants has been underrated.

The Cholinergic System Contributes to the Immunopathological Progression of Experimental Pulmonary Tuberculosis

The cholinergic system is present in both bacteria and mammals and regulates inflammation during bacterial respiratory infections through neuronal and non-neuronal production of acetylcholine (ACh) and its receptors. However, the presence of this system during the immunopathogenesis of pulmonary tuberculosis (TB) in vivo and in its causative agent Mycobacterium tuberculosis (Mtb) has not been studied. Therefore, we used an experimental model of progressive pulmonary TB in BALB/c mice to quantify pulmonary ACh using high-performance liquid chromatography during the course of the disease. In addition, we performed immunohistochemistry in lung tissue to determine the cellular expression of cholinergic system components, and then administered nicotinic receptor (nAChR) antagonists to validate their effect on lung bacterial burden, inflammation, and pro-inflammatory cytokines. Finally, we subjected Mtb cultures to colorimetric analysis to reveal the production of ACh and the effect of ACh and nAChR antagonists on Mtb growth. Our results show high concentrations of ACh and expression of its synthesizing enzyme choline acetyltransferase (ChAT) during early infection in lung epithelial cells and macrophages. During late progressive TB, lung ACh upregulation was even higher and coincided with ChAT and α7 nAChR subunit expression in immune cells. Moreover, the administration of nAChR antagonists increased pro-inflammatory cytokines, reduced bacillary loads and synergized with antibiotic therapy in multidrug resistant TB. Finally, in vitro studies revealed that the bacteria is capable of producing nanomolar concentrations of ACh in liquid culture. In addition, the administration of ACh and nicotinic antagonists to Mtb cultures induced or inhibited bacterial proliferation, respectively. These results suggest that Mtb possesses a cholinergic system and upregulates the lung non-neuronal cholinergic system, particularly during late progressive TB. The upregulation of the cholinergic system during infection could aid both bacterial growth and immunomodulation within the lung to favor disease progression. Furthermore, the therapeutic efficacy of modulating this system suggests that it could be a target for treating the disease.

Investigation of the Distribution and Content of Acetylcholine, a Novel Functional Compound in Eggplant

Eggplants are rich in acetylcholine (ACh), which can improve high blood pressure and negative psychological states. However, information on ACh content in individual parts of eggplant and the changes in ACh content during eggplant development is limited. Therefore, we investigated the ACh content in various parts of eggplant, namely, the leaf, root, bud, calyx, ovary, fruit, exocarp, mesocarp, partition, placenta, core, fruit base, fruit center, and fruit top in 26 eggplant varieties. Furthermore, the effect of heat treatment on ACh content was investigated. The ACh content significantly differed among the eggplant varieties. The difference between the varieties with the highest and lowest ACh content was 100-fold (Tosataka: 11 ± 0.61 mg/100 g fresh weight (FW) and Ryoma: 0.11 ± 0.046 mg/100 g FW, respectively). Eggplant fruit presented the highest ACh content (4.8 mg/100 g FW); it was three times higher than that in other parts combined (1.6 mg/100 g FW). The root contained the lowest ACh content among all parts. The ACh content increased with growth after flowering. The ACh content in the fruit 1.5 months after flowering was 400 times that in the ovary. ACh was uniformly distributed in eggplant flesh. Heat treatment did not cause ACh loss in eggplant. Thus, eggplant is an excellent raw material for functional foods.

Comparative transcriptome analysis reveals the regulatory effects of acetylcholine on salt tolerance of Nicotiana benthamiana

Salinity is a major cause of crop losses worldwide. Acetylcholine (ACh) can ameliorate the adverse effects of abiotic stresses on plant growth, including salinity stress; however, the underlying molecular mechanisms of this process are unclear. Here, seedlings of Nicotiana benthamiana grown under normal conditions or exposed to 150 mmol L-1 NaCl salinity stress were then treated with a root application of 10 μM ACh. Exogenous ACh application resulted in the downregulation of the activity of the antioxidant enzymes, ascorbate peroxidase, and catalase. ACh-treated plants had lower levels of reactive oxygen species, including the superoxide anion radical and hydrogen peroxide. Transcriptome analysis indicated that ACh treatment under salt stress promoted the differential expression of 658 genes in leaves of N. benthamiana (527 were upregulated and 131 were downregulated). Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that exogenous ACh application was associated with a substantial increase in the transcripts of genes related to cell wall peroxidases, xyloglucan endotransglucosylases or hydrolases, and expansins, indicating that ACh activates cell wall biosynthesis in salt-stressed plants. ACh also enhanced the expression of genes associated with the auxin, gibberellin, brassinosteroid, and salicylic acid signalling pathways, indicating that ACh induces the activation of these pathways under salt stress. Collectively, these findings indicate that ACh-induced salt tolerance in N. benthamiana seedlings is mediated by the inhibition of antioxidant enzymes, activation of cell wall biosynthesis, and hormone signalling pathways. Stress-induced genes involved in osmotic regulation and oxidation resistance were induced by ACh under salt stress. The genes whose transcript levels were elevated by ACh treatment in salt-stressed N. benthamiana could be used as molecular markers of the physiological status of plants under salt stress.

Association of Salivary Cholinesterase With Arthropod Vectors of Disease

Acetylcholinesterase (AChE) was previously reported to be present in saliva of the southern cattle tick, Rhipicephalus (Boophilus) microplus (Canestrini), with proposed potential functions to 1) reduce acetylcholine toxicity during rapid engorgement, 2) modulate host immune responses, and 3) to influence pathogen transmission and establishment in the host. Potential modulation of host immune responses might include participation in salivary-assisted transmission and establishment of pathogens in the host as has been reported for a number of arthropod vector-borne diseases. If the hypothesis that tick salivary AChE may alter host immune responses is correct, we reasoned that similar cholinesterase activities might be present in saliva of additional arthropod vectors. Here, we report the presence of AChE-like activity in the saliva of southern cattle ticks, Rhipicephalus (Boophilus) microplus; the lone star tick, Amblyomma americanum (Linnaeus); Asian tiger mosquitoes, Aedes albopictus (Skuse); sand flies, Phlebotomus papatasi (Scopoli); and biting midges, Culicoides sonorensis Wirth and Jones. Salivary AChE-like activity was not detected for horn flies Haematobia irritans (L.), stable flies Stomoxys calcitrans (L.), and house flies Musca domestica L. Salivary cholinesterase (ChE) activities of arthropod vectors of disease-causing agents exhibited various Michaelis-Menten KM values that were each lower than the KM value of bovine serum AChE. A lower KM value is indicative of higher affinity for substrate and is consistent with a hypothesized role in localized depletion of host tissue acetylcholine potentially modulating host immune responses at the arthropod bite site that may favor ectoparasite blood-feeding and alter host defensive responses against pathogen transmission and establishment.

Functional Characterization of Cholinergic Receptors in Melanoma Cells

In the last two decades, the scientific community has come to terms with the importance of non-neural acetylcholine in light of its multiple biological and pathological functions within and outside the nervous system. Apart from its well-known physiological role both in the central and peripheral nervous systems, in the autonomic nervous system, and in the neuromuscular junction, the expression of the acetylcholine receptors has been detected in different peripheral organs. This evidence has contributed to highlight new roles for acetylcholine in various biological processes, (e.g., cell viability, proliferation, differentiation, migration, secretion). In addition, growing evidence in recent years has also demonstrated new roles for acetylcholine and its receptors in cancer, where they are involved in the modulation of cell proliferation, apoptosis, angiogenesis, and epithelial mesenchymal transition. In this review, we describe the functional characterization of acetylcholine receptors in different tumor types, placing attention on melanoma. The latest set of data accessible through literature, albeit limited, highlights how cholinergic receptors both of muscarinic and nicotinic type can play a relevant role in the migratory processes of melanoma cells, suggesting their possible involvement in invasion and metastasis.

LC-MS/MS Analysis of Choline Compounds in Japanese-Cultivated Vegetables and Fruits

Choline is an essential nutrient and choline esters are potential functional food ingredients. We aimed to analyze the choline compound content in 19 cultivated fruits and vegetables and identify those with high acetylcholine content. We utilized liquid chromatography with tandem mass spectrometry to quantify choline compounds according to the standard addition method. Choline compounds were extracted from lyophilized fruit/vegetable powders and passed through a weakly acidic cation exchange column, resulting in a concentrated solution of choline compounds. The compounds were separated on a pentafluorophenyl column and then analyzed using positive mode electrospray ionization. Results showed that acetylcholine and choline were the primary choline compounds in all agricultural products; propionylcholine and butyrylcholine were minor compounds in 17 and 12 agricultural products, respectively. The acetylcholine concentration was 2900-fold higher in eggplants (6.12 mg/100 g fresh weight [FW]) than in other agricultural products (average: 2.11 × 10⁻³ mg/100 g FW). The concentration of acetylcholine differed only 2-fold between eggplant cultivars with the highest (′Higomurasaki′: 5.53 mg/100 g FW) and lowest (′Onaga nasu′: 2.79 mg/100 g FW) concentrations. The half-life of acetylcholine in eggplants was approximately 16 days, which is longer the shelf life of eggplants. Thus, eggplants can be a good source of acetylcholine.

Toxicity thresholds of three insecticides and two fungicides to larvae of the coral Acropora tenuis

Tropical marine ecosystems, such as coral reefs, face several threats to their health and resilience, including poor water quality. Previous studies on the risks posed by pesticides have focused on five priority herbicides; however, as the number of pesticides applied in coastal agriculture increases, a suite of 'alternative' pesticides is being detected in tropical nearshore waters. To improve our understanding of the risks posed by alternative pesticides to tropical marine organisms, the effects of three insecticides (diazinon, fipronil, imidacloprid) and two fungicides (chlorothalonil, propiconazole) were tested on larval metamorphosis of the coral Acropora tenuis. A. tenuis larvae were affected by all five pesticides and the reference toxicant copper. The no effect concentration (NEC) and the 10% and 50% effect concentrations (EC10 and EC50, respectively) for larval metamorphosis were estimated from concentration-response curves after 48 h exposure. The NEC, EC10 and EC50 (in µg L-1), respectively, of each pesticide were as follows: chlorothalonil (2.4, 2.8, 6.0); fipronil (12.3, 13.9, 29.1); diazinon (38.0, 40.8, 54.7); imidacloprid (263, 273, 347); and propiconazole (269, 330, 1008). These toxicity thresholds are higher than reported concentrations in monitoring programs; however, these data will contribute to improving water quality guideline values, which inform the total risk assessments posed by complex contaminant mixtures to which these pesticides contribute.