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1.
Ecotoxicol Environ Saf ; 203: 111014, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888589

RESUMO

Tributyltin (TBT), a widely and persistently distributed organontin, has been well documented to disrupt reproduction and behaviors in animals due to its anti-aromatase activity. TBT has been also reported to enhance anxiety in several fish species, whereas the mechanism underlying remains largely unknown. To investigate the disruption of TBT on fish anxiety and the mechanisms possibly involved, adult male zebrafish (Danio rerio) were treated with TBT (100 and 500 ng/L) for 28 days and anxiety behavior was further investigated using a novel tank dive test. Result showed that TBT treatment significantly enhanced the total time of the fish spent in the lower half, delayed the onset time to the higher half of the tank and increased the total duration of freezing of the fish, indicating an enhanced anxiety in TBT-treated fish. Accordingly, TBT sharply elevated the cortisol levels in plasma in a concentration-dependent manner, suggesting that the elevated cortisol level might be involved in the enhanced anxiety. Although the expression of crha was significantly increased and crhbp was significantly decreased in the brain of TBT-treated fish which is consistent to the elevated cortisol level, the expressions of actha and acthb were sharply down-regulated. In contrast, the expressions of genes responsible for the synthesis and action of serotonin (5-HT) (pet1, thp2 and htr1aa), dopamine (DA) (th1, slc6a3, drd2a and drd2b) and gamma-aminobutyric acid (GABA) (gad2 and gabrg2) were all significantly inhibited. The down-regulation of these pivotal genes acting in 5-HT, DA and GABA neurotransmitter systems in response to TBT corresponded well with the TBT-enhanced anxiety in fish. It was thus strongly suggested that these neurotransmitters might be also involved in TBT-enhanced anxiety in adult male zebrafish. The present study extended our understanding of the neurotoxicity of TBT on the anxiety control and behavioral modulation in fish.


Assuntos
Ansiedade/induzido quimicamente , Hidrocortisona/metabolismo , Neurotransmissores/metabolismo , Compostos de Trialquitina/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Dopamina/metabolismo , Masculino , Serotonina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Peixe-Zebra/metabolismo , Ácido gama-Aminobutírico/metabolismo
2.
Int J Nanomedicine ; 15: 6339-6353, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32922005

RESUMO

Introduction: Epilepsy is a chronic neurological condition characterized by behavioral, molecular, and neurochemical alterations. Current antiepileptic drugs are associated with various adverse impacts. The main goal of the current study is to investigate the possible anticonvulsant effect of selenium nanoparticles (SeNPs) against pentylenetetrazole (PTZ)-mediated epileptic seizures in mice hippocampus. Sodium valproate (VPA) was used as a standard anti-epileptic drug. Methods: Mice were assigned into five groups (n=15): control, SeNPs (5 mg/kg, orally), PTZ (60 mg/kg, intraperitoneally), SeNPs+PTZ and VPA (200 mg/kg)+PTZ. All groups were treated for 10 days. Results: PTZ injection triggered a state of oxidative stress in the hippocampal tissue as represented by the elevated lipoperoxidation, heat shock protein 70 level, and nitric oxide formation while decreased glutathione level and antioxidant enzymes activity. Additionally, the blotting analysis showed downregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in the epileptic mice. A state of neuroinflammation was recorded following the developed seizures represented by the increased pro-inflammatory cytokines. Moreover, neuronal apoptosis was recorded following the development of epileptic convulsions. At the neurochemical level, acetylcholinesterase activity and monoamines content were decreased in the epileptic mice, accompanied by high glutamate and low GABA levels in the hippocampal tissue. However, SeNP supplementation was found to delay the onset and decreased the duration of tonic, myoclonic, and generalized seizures following PTZ injection. Moreover, SeNPs were found to provide neuroprotection through preventing the development of oxidative challenge via the upregulation of Nrf2 and HO-1, inhibiting the inflammatory response and apoptotic cascade. Additionally, SeNPs reversed the changes in the activity and levels of neuromodulators following the development of epileptic seizures. Conclusion: The obtained results suggest that SeNPs could be used as a promising anticonvulsant drug due to its potent antioxidant, anti-inflammatory, and neuromodulatory activities.


Assuntos
Nanopartículas/química , Neurônios/patologia , Estresse Oxidativo/efeitos dos fármacos , Convulsões/tratamento farmacológico , Selênio/uso terapêutico , Aminoácidos , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Anticonvulsivantes/efeitos adversos , Anticonvulsivantes/farmacologia , Anticonvulsivantes/uso terapêutico , Apoptose/efeitos dos fármacos , Colinérgicos/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Masculino , Camundongos , Nanopartículas/administração & dosagem , Neurônios/efeitos dos fármacos , Neurotransmissores/metabolismo , Oxirredução , Pentilenotetrazol , Convulsões/induzido quimicamente , Convulsões/prevenção & controle , Selênio/administração & dosagem , Selênio/farmacologia
3.
Yakugaku Zasshi ; 140(8): 979-983, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32741871

RESUMO

Monoamine neurotransmitters are released by specialized neurons that regulate behavioral and cognitive functions. Although localization of monoaminergic neurons in the brain is well known, the distribution, concentration, and kinetics of monoamines remain unclear. We used mass spectrometry imaging (MSI) for simultaneous and quantitative imaging of endogenous monoamines to generate a murine brain atlas of serotonin (5-HT), dopamine (DA), and norepinephrine (NE) levels. We observed several nuclei rich in both 5-HT and a catecholamine (DA or NE). Additionally, we analyzed de novo monoamine synthesis or fluctuations in those nuclei. We propose that MSI is a useful tool to gain deeper understanding of associations among the localization, levels, and turnover of monoamines in different brain areas and their role in inducing behavioral changes.


Assuntos
Monoaminas Biogênicas/análise , Monoaminas Biogênicas/metabolismo , Mapeamento Encefálico/métodos , Encéfalo/metabolismo , Espectrometria de Massas/métodos , Imagem Molecular/métodos , Neurotransmissores/metabolismo , Animais , Dopamina/análise , Dopamina/metabolismo , Camundongos , Neurônios/metabolismo , Neurotransmissores/fisiologia , Norepinefrina/análise , Norepinefrina/metabolismo , Serotonina/análise , Serotonina/metabolismo
4.
Adv Exp Med Biol ; 1265: 167-185, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32761576

RESUMO

Amino acids (AAs) and their metabolites play an important role in neurological health and function. They are not only the building blocks of protein but are also neurotransmitters. In the brain, glutamate and aspartate are the major excitatory neurotransmitters, whereas γ-aminobutyrate (GABA, a metabolite of glutamate) and glycine are the major inhibitory neurotransmitters. Nitric oxide (NO, a metabolite of arginine), H2S (a metabolite of cysteine), serotonin (a metabolite of tryptophan) and histamine (a metabolite of histidine), as well as dopamine and norepinephrine (metabolites of tyrosine) are neurotransmitters to modulate synaptic plasticity, neuronal activity, learning, motor control, motivational behavior, emotion, and executive function. Concentrations of glutamine (a precursor of glutamate and aspartate), branched-chain AAs (precursors of glutamate, glutamine and aspartate), L-serine (a precursor of glycine and D-serine), methionine and phenylalanine in plasma are capable of affecting neurotransmission through the syntheses of glutamate, aspartate, and glycine, as well as the competitive transport of tryptophan and tyrosine across from the blood-brain barrier. Adequate consumption of AAs is crucial to maintain their concentrations and the production of neurotransmitters in the central nervous system. Thus, the content and balance of AAs in diets have a profound impact on food intake by animals. Knowledge of AA transport and metabolism in the brain is beneficial for improving the health and well-being of humans and animals.


Assuntos
Aminoácidos/metabolismo , Encéfalo/metabolismo , Comportamento Alimentar/fisiologia , Animais , Humanos , Neurotransmissores/metabolismo
5.
Biol Res ; 53(1): 36, 2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-32843088

RESUMO

BACKGROUND: To investigate the thalamic neurotransmitters and functional connections in the development of chronic constriction injury (CCI)-induced neuropathic pain. METHODS: The paw withdrawal threshold was measured by mechanical stimulation the right hind paw with the von frey hair in the rats of CCI-induced neuropathic pain. The N-acetylaspartate (NAA) and Glutamate (Glu) in thalamus were detected by magnetic resonance spectrum (MRS) process. The thalamic functional connectivity with other brain regions was scanned by functional magnetic resonance image (fMRI). RESULTS: The paw withdrawal threshold of the ipsilateral side showed a noticeable decline during the pathological process. Increased concentrations of Glu and decreased levels of NAA in the thalamus were significantly correlated with mechanical allodynia in the neuropathic pain states. The thalamic regional homogeneity (ReHo) decreased during the process of neuropathic pain. The functional connectivity among the thalamus with the insula and somatosensory cortex were significantly increased at different time points (7, 14, 21 days) after CCI surgery. CONCLUSION: Our study suggests that dynamic changes in thalamic NAA and Glu levels contribute to the thalamic functional connection hyper-excitation during CCI-induced neuropathic pain. Enhanced thalamus-insula functional connection might have a significant effect on the occurrence of neuropathic pain.


Assuntos
Neuralgia , Neurotransmissores/metabolismo , Tálamo/metabolismo , Ferimentos e Lesões/fisiopatologia , Animais , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Constrição , Ácido Glutâmico/metabolismo , Hiperalgesia , Ratos , Tálamo/fisiopatologia
6.
PLoS One ; 15(8): e0237371, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32845904

RESUMO

The neurotransmitter gamma-aminobutyric acid (GABA) is the most abundant inhibitory neurotransmitter in the human brain; however, it is becoming more evident that this non-proteinogenic amino acid plays multiple physiological roles in biology. In the present study, the transport and function of GABA is studied in the highly infectious intracellular bacterium Brucella abortus. The data show that 3H-GABA is imported by B. abortus under nutrient limiting conditions and that the small RNAs AbcR1 and AbcR2 negatively regulate this transport. A specific transport system, gts, is responsible for the transport of GABA as determined by measuring 3H-GABA transport in isogenic deletion strains of known AbcR1/2 regulatory targets; however, this locus is unnecessary for Brucella infection in BALB/c mice. Similar assays revealed that 3H-GABA transport is uninhibited by the 20 standard proteinogenic amino acids, representing preference for the transport of 3H-GABA. Metabolic studies did not show any potential metabolic utilization of GABA by B. abortus as a carbon or nitrogen source, and RNA sequencing analysis revealed limited transcriptional differences between B. abortus 2308 with or without exposure to GABA. While this study provides evidence for GABA transport by B. abortus, questions remain as to why and when this transport is utilized during Brucella pathogenesis.


Assuntos
Brucella abortus/metabolismo , Neurotransmissores/metabolismo , Ácido gama-Aminobutírico/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Brucella abortus/efeitos dos fármacos , Brucella abortus/fisiologia , Ácido Glutâmico/farmacologia , Camundongos , Camundongos Endogâmicos BALB C
7.
J Pharmacol Sci ; 144(3): 151-164, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32807662

RESUMO

Glutamate is the major excitatory neurotransmitter in the central nervous system. Glutamate transmission efficiency depends on the correct functionality and expression of a plethora of receptors and transporters, located both on neurons and glial cells. Of note, glutamate reuptake by dedicated transporters prevents its accumulation at the synapse as well as non-physiological spillover. Indeed, extracellular glutamate increase causes aberrant synaptic signaling leading to neuronal excitotoxicity and death. Moreover, extrasynaptic glutamate diffusion is strongly associated with glia reaction and neuroinflammation. Glutamate-induced excitotoxicity is mainly linked to an impaired ability of glial cells to reuptake and respond to glutamate, then this is considered a common hallmark in many neurodegenerative diseases, including Parkinson's disease (PD). In this review, we discuss the function of astrocytes and microglia in glutamate homeostasis, focusing on how glial dysfunction causes glutamate-induced excitotoxicity leading to neurodegeneration in PD.


Assuntos
Ácido Glutâmico/metabolismo , Ácido Glutâmico/toxicidade , Neuroglia/metabolismo , Neurotransmissores/metabolismo , Neurotransmissores/toxicidade , Doença de Parkinson/etiologia , Sistema X-AG de Transporte de Aminoácidos/metabolismo , Homeostase , Humanos , Inflamação , Doença de Parkinson/metabolismo , Receptores de Glutamato/metabolismo
9.
Nat Commun ; 11(1): 3752, 2020 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-32719334

RESUMO

Glycinergic synapses play a central role in motor control and pain processing in the central nervous system. Glycine receptors (GlyRs) are key players in mediating fast inhibitory neurotransmission at these synapses. While previous high-resolution structures have provided insights into the molecular architecture of GlyR, several mechanistic questions pertaining to channel function are still unanswered. Here, we present Cryo-EM structures of the full-length GlyR protein complex reconstituted into lipid nanodiscs that are captured in the unliganded (closed), glycine-bound (open and desensitized), and allosteric modulator-bound conformations. A comparison of these states reveals global conformational changes underlying GlyR channel gating and modulation. The functional state assignments were validated by molecular dynamics simulations, and the observed permeation events are in agreement with the anion selectivity and conductance of GlyR. These studies provide the structural basis for gating, ion selectivity, and single-channel conductance properties of GlyR in a lipid environment.


Assuntos
Ativação do Canal Iônico , Lipídeos/química , Nanopartículas/química , Receptores da Glicina/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Regulação Alostérica , Animais , Sítios de Ligação , Glicina/metabolismo , Simulação de Dinâmica Molecular , Neurotransmissores/metabolismo , Conformação Proteica , Receptores da Glicina/ultraestrutura , Xenopus , Proteínas de Peixe-Zebra/ultraestrutura
10.
Chem Biol Interact ; 328: 109144, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32653415

RESUMO

The debilitating nature of cognitive impairment in epilepsy and the potential of some traditional antiepileptics to further deteriorate cognitive function are areas of growing concern. Glucagon-like peptide-1 (GLP-1) deficiency has been linked to reduced seizure threshold as well as cognitive dysfunction. Here, we tested whether sitagliptin (SITA), by virtue of its neuroprotective properties, could alleviate both epilepsy and associated cognitive dysfunction in a rat model of kindling epilepsy. Chemical kindling was induced by subconvulsive doses of pentylenetetrazol (PTZ) (30 mg/kg; i.p). SITA (50 mg/kg; p.o) was administered 1 h before PTZ injections. SITA conceivably attenuated PTZ hippocampal histological insult, preserved neuronal integrity and amended neurotransmitter perturbations in rat hippocampi paralleled with enhanced hippocampal GLP-1 levels as well as the downstream cAMP content and protein kinase A (PKA) activity. Moreover, SITA improved cognitive functioning of rats in the Morris water maze which was coupled with hampered hippocampal p(Ser404)-tau and ß-amyloid proteins. SITA replenished p(Ser9)-glycogen synthase kinase-3ß (GSK-3ß). It also opposed the boosted matrix metalloproteinase-9 (MMP-9), brain-derived neurotrophic factor (BDNF), and insulin-like growth factor-1 (IGF-1) levels associated with PTZ administration along with mitigation of both ß-secretase-1 (BACE1) immunoreactivity and receptor for advanced glycation end products (RAGE) protein level in rat hippocampi. In conclusion, SITA subdues epileptic and cognitive upshots of PTZ kindling in rats, which might correspond to the modulation of BACE1, amyloidogenic/RAGE axis as well as GSK-3ß/MMP-9/BDNF signaling cascade. SITA effects are probably mediated via boosting GLP-1 and subsequently enhancing GLP-1/GLP-1R signaling.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Transtornos Cognitivos/induzido quimicamente , Transtornos Cognitivos/metabolismo , Excitação Neurológica/efeitos dos fármacos , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Transdução de Sinais , Fosfato de Sitagliptina/farmacologia , Peptídeos beta-Amiloides/metabolismo , Animais , Biomarcadores/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Transtornos Cognitivos/patologia , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Inibição Neural/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Neurotransmissores/metabolismo , Pentilenotetrazol , Ratos Wistar , Convulsões/induzido quimicamente , Convulsões/metabolismo , Convulsões/patologia , Transdução de Sinais/efeitos dos fármacos , Memória Espacial/efeitos dos fármacos , Proteínas tau/metabolismo
11.
Nature ; 582(7811): 246-252, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32499648

RESUMO

A wealth of specialized neuroendocrine command systems intercalated within the hypothalamus control the most fundamental physiological needs in vertebrates1,2. Nevertheless, we lack a developmental blueprint that integrates the molecular determinants of neuronal and glial diversity along temporal and spatial scales of hypothalamus development3. Here we combine single-cell RNA sequencing of 51,199 mouse cells of ectodermal origin, gene regulatory network (GRN) screens in conjunction with genome-wide association study-based disease phenotyping, and genetic lineage reconstruction to show that nine glial and thirty-three neuronal subtypes are generated by mid-gestation under the control of distinct GRNs. Combinatorial molecular codes that arise from neurotransmitters, neuropeptides and transcription factors are minimally required to decode the taxonomical hierarchy of hypothalamic neurons. The differentiation of γ-aminobutyric acid (GABA) and dopamine neurons, but not glutamate neurons, relies on quasi-stable intermediate states, with a pool of GABA progenitors giving rise to dopamine cells4. We found an unexpected abundance of chemotropic proliferation and guidance cues that are commonly implicated in dorsal (cortical) patterning5 in the hypothalamus. In particular, loss of SLIT-ROBO signalling impaired both the production and positioning of periventricular dopamine neurons. Overall, we identify molecular principles that shape the developmental architecture of the hypothalamus and show how neuronal heterogeneity is transformed into a multimodal neural unit to provide virtually infinite adaptive potential throughout life.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Hipotálamo/citologia , Hipotálamo/embriologia , Morfogênese , Animais , Diferenciação Celular , Linhagem da Célula , Dopamina/metabolismo , Neurônios Dopaminérgicos/citologia , Neurônios Dopaminérgicos/metabolismo , Ectoderma/citologia , Ectoderma/metabolismo , Feminino , Neurônios GABAérgicos/citologia , Neurônios GABAérgicos/metabolismo , Redes Reguladoras de Genes , Estudo de Associação Genômica Ampla , Ácido Glutâmico/metabolismo , Hipotálamo/metabolismo , Masculino , Camundongos , Morfogênese/genética , Proteínas do Tecido Nervoso/metabolismo , Neuroglia/citologia , Neuroglia/metabolismo , Neuropeptídeos/metabolismo , Neurotransmissores/metabolismo , Receptores Imunológicos/metabolismo , Regulon/genética , Transdução de Sinais , Fatores de Transcrição/metabolismo , Ácido gama-Aminobutírico/metabolismo
12.
Nature ; 583(7816): 415-420, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32555456

RESUMO

Animals coexist in commensal, pathogenic or mutualistic relationships with complex communities of diverse organisms, including microorganisms1. Some bacteria produce bioactive neurotransmitters that have previously been proposed to modulate nervous system activity and behaviours of their hosts2,3. However, the mechanistic basis of this microbiota-brain signalling and its physiological relevance are largely unknown. Here we show that in Caenorhabditis elegans, the neuromodulator tyramine produced by commensal Providencia bacteria, which colonize the gut, bypasses the requirement for host tyramine biosynthesis and manipulates a host sensory decision. Bacterially produced tyramine is probably converted to octopamine by the host tyramine ß-hydroxylase enzyme. Octopamine, in turn, targets the OCTR-1 octopamine receptor on ASH nociceptive neurons to modulate an aversive olfactory response. We identify the genes that are required for tyramine biosynthesis in Providencia, and show that these genes are necessary for the modulation of host behaviour. We further find that C. elegans colonized by Providencia preferentially select these bacteria in food choice assays, and that this selection bias requires bacterially produced tyramine and host octopamine signalling. Our results demonstrate that a neurotransmitter produced by gut bacteria mimics the functions of the cognate host molecule to override host control of a sensory decision, and thereby promotes fitness of both the host and the microorganism.


Assuntos
Caenorhabditis elegans/microbiologia , Caenorhabditis elegans/fisiologia , Comportamento Alimentar/fisiologia , Intestinos/microbiologia , Neurotransmissores/metabolismo , Providencia/metabolismo , Olfato/fisiologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Proteínas de Caenorhabditis elegans/metabolismo , Microbioma Gastrointestinal/fisiologia , Metabolômica , Mutação , Octanóis/farmacologia , Octopamina/biossíntese , Octopamina/metabolismo , Providencia/enzimologia , Providencia/fisiologia , Receptores de Amina Biogênica/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Células Receptoras Sensoriais/metabolismo , Olfato/efeitos dos fármacos , Tiramina/biossíntese , Tiramina/metabolismo
13.
Sheng Wu Gong Cheng Xue Bao ; 36(6): 1051-1059, 2020 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-32597056

RESUMO

Neurotransmitters play an important role in nervous system. Temporal and spatial changes of neurotransmitter distribution are crucial to information processing in neural networks. Biosensors that can visually monitor neurotransmitters are one of the vital tools to explore a variety of physiological and pathological activities. This article reviews recent advances in monitoring neurotransmitters with high temporal and spatial resolution, and introduces the latest fluorescent imaging methods for typical neurotransmitters, including glutamate, dopamine, γ-aminobutyric acid and acetylcholine. The article also summarizes the basic principles, advantages and disadvantages of various visually detection methods, and provides systematic suggestions for designing neurotransmitter sensors with high temporal and spatial resolution.


Assuntos
Técnicas Biossensoriais , Neurotransmissores , Animais , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/tendências , Fluorescência , Humanos , Neurotransmissores/metabolismo
14.
Nat Commun ; 11(1): 2399, 2020 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-32404879

RESUMO

The ability to monitor molecules volumetrically throughout the body could provide valuable biomarkers for studies of healthy function and disease, but noninvasive detection of molecular targets in living subjects often suffers from poor sensitivity or selectivity. Here we describe a family of potent imaging probes that can be activated by molecules of interest in deep tissue, providing a basis for mapping nanomolar-scale analytes without the radiation or heavy metal content associated with traditional molecular imaging agents. The probes are reversibly caged vasodilators that induce responses detectable by hemodynamic imaging; they are constructed by combining vasoactive peptides with synthetic chemical appendages and protein blocking domains. We use this architecture to create ultrasensitive biotin-responsive imaging agents, which we apply for wide-field mapping of targets in rat brains using functional magnetic resonance imaging. We also adapt the sensor design for detecting the neurotransmitter dopamine, illustrating versatility of this approach for addressing biologically important molecules.


Assuntos
Imagem Molecular/métodos , Sondas Moleculares/metabolismo , Peptídeos/metabolismo , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismo , Vasodilatadores/metabolismo , Animais , Biotina/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Células CHO , Cricetinae , Cricetulus , Dopamina/metabolismo , Células HEK293 , Humanos , Imagem por Ressonância Magnética/métodos , Sondas Moleculares/química , Neurotransmissores/metabolismo , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/química , Ratos , Reprodutibilidade dos Testes , Vasodilatadores/química
15.
Nat Commun ; 11(1): 2195, 2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32366867

RESUMO

Physical exercise promotes motor skill learning in normal individuals and those with neurological disorders but its mechanism of action is unclear. We find that one week of voluntary wheel running enhances the acquisition of motor skills in normal adult mice. One week of running also induces switching from ACh to GABA expression in neurons in the caudal pedunculopontine nucleus (cPPN). Consistent with regulation of motor skills, we show that the switching neurons make projections to the substantia nigra (SN), ventral tegmental area (VTA) and ventrolateral-ventromedial nuclei of the thalamus (VL-VM). Use of viral vectors to override transmitter switching blocks the beneficial effect of running on motor skill learning. We suggest that neurotransmitter switching provides the basis by which sustained running benefits motor skill learning, presenting a target for clinical treatment of movement disorders.


Assuntos
Aprendizagem/fisiologia , Mesencéfalo/fisiologia , Atividade Motora/fisiologia , Destreza Motora/fisiologia , Neurotransmissores/metabolismo , Condicionamento Físico Animal/fisiologia , Acetilcolina/metabolismo , Animais , Feminino , Masculino , Mesencéfalo/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Transtornos dos Movimentos/metabolismo , Transtornos dos Movimentos/fisiopatologia , Transtornos dos Movimentos/prevenção & controle , Ácido gama-Aminobutírico/metabolismo
16.
Environ Toxicol ; 35(10): 1137-1145, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32463565

RESUMO

The low dose of radiation (LDR) has received growing attention for its beneficial neuroprotective effect. This study was designed to investigate the enhancing effect of LDR on the antidepressant potential of resveratrol against diazepam-induced depression in mice. Female mice divided into five groups; control, diazepam (2 mg/kg), LDR (0.5Gy) + diazepam, resveratrol (20 mg/kg) + diazepam, LDR + resveratrol+diazepam. Mice received diazepam showed depressive symptoms as evidenced by decreased locomotor activity in the open field and increased immobility time in the forced swimming and tail suspension tests integrated with a marked decline in biogenic amines (serotonin, norepinephrine, and dopamine) in brain tissues. These effects were ameliorated by LDR or resveratrol administration demonstrating an antidepressant activity. Interestingly, LDR triggered the antidepressant effect of resveratrol as it restored the changes in behavioral tests, neurotransmitters, and neuro-histoarchitecture. In conclusion, these findings suggested that LDR could be considered as a novel adjuvant that augmented the resveratrol antidepressant effect and might serve as a potential therapeutic approach for depression.


Assuntos
Antidepressivos/farmacologia , Comportamento Animal , Química Encefálica , Depressão/tratamento farmacológico , Raios gama , Fármacos Neuroprotetores/farmacologia , Resveratrol/farmacologia , Animais , Antidepressivos/uso terapêutico , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/efeitos da radiação , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/efeitos da radiação , Química Encefálica/efeitos dos fármacos , Química Encefálica/efeitos da radiação , Feminino , Elevação dos Membros Posteriores , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Atividade Motora/efeitos da radiação , Fármacos Neuroprotetores/uso terapêutico , Neurotransmissores/metabolismo , Doses de Radiação , Resveratrol/uso terapêutico , Irradiação Corporal Total
17.
PLoS One ; 15(5): e0232991, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32407359

RESUMO

Following nerve stimulation, there are two distinct phases of Ca2+-dependent neurotransmitter release: a fast, synchronous release phase, and a prolonged, asynchronous release phase. Each of these phases is tightly regulated and mediated by distinct mechanisms. Synaptotagmin 1 is the major Ca2+ sensor that triggers fast, synchronous neurotransmitter release upon Ca2+ binding by its C2A and C2B domains. It has also been implicated in the inhibition of asynchronous neurotransmitter release, as blocking Ca2+ binding by the C2A domain of synaptotagmin 1 results in increased asynchronous release. However, the mutation used to block Ca2+ binding in the previous experiments (aspartate to asparagine mutations, sytD-N) had the unintended side effect of mimicking Ca2+ binding, raising the possibility that the increase in asynchronous release was directly caused by ostensibly constitutive Ca2+ binding. Thus, rather than modulating an asynchronous sensor, sytD-N may be mimicking one. To directly test the C2A inhibition hypothesis, we utilized an alternate C2A mutation that we designed to block Ca2+ binding without mimicking it (an aspartate to glutamate mutation, sytD-E). Analysis of both the original sytD-N mutation and our alternate sytD-E mutation at the Drosophila neuromuscular junction showed differential effects on asynchronous release, as well as on synchronous release and the frequency of spontaneous release. Importantly, we found that asynchronous release is not increased in the sytD-E mutant. Thus, our work provides new mechanistic insight into synaptotagmin 1 function during Ca2+-evoked synaptic transmission and demonstrates that Ca2+ binding by the C2A domain of synaptotagmin 1 does not inhibit asynchronous neurotransmitter release in vivo.


Assuntos
Proteínas de Drosophila/metabolismo , Neurotransmissores/metabolismo , Sinaptotagmina I/metabolismo , Substituição de Aminoácidos , Animais , Animais Geneticamente Modificados , Sítios de Ligação/genética , Cálcio/metabolismo , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Genes de Insetos , Mutagênese Sítio-Dirigida , Domínios Proteicos , Transmissão Sináptica , Vesículas Sinápticas/metabolismo , Sinaptotagmina I/química , Sinaptotagmina I/genética
18.
J Neurosci ; 40(18): 3504-3516, 2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32265260

RESUMO

The action potential (AP) waveform controls the opening of voltage-gated calcium channels and contributes to the driving force for calcium ion flux that triggers neurotransmission at presynaptic nerve terminals. Although the frog neuromuscular junction (NMJ) has long been a model synapse for the study of neurotransmission, its presynaptic AP waveform has never been directly studied, and thus the AP waveform shape and propagation through this long presynaptic nerve terminal are unknown. Using a fast voltage-sensitive dye, we have imaged the AP waveform from the presynaptic terminal of male and female frog NMJs and shown that the AP is very brief in duration and actively propagated along the entire length of the terminal. Furthermore, based on measured AP waveforms at different regions along the length of the nerve terminal, we show that the terminal is divided into three distinct electrical regions: A beginning region immediately after the last node of Ranvier where the AP is broadest, a middle region with a relatively consistent AP duration, and an end region near the tip of nerve terminal branches where the AP is briefer. We hypothesize that these measured changes in the AP waveform along the length of the motor nerve terminal may explain the proximal-distal gradient in transmitter release previously reported at the frog NMJ.SIGNIFICANCE STATEMENT The AP waveform plays an essential role in determining the behavior of neurotransmission at the presynaptic terminal. Although the frog NMJ is a model synapse for the study of synaptic transmission, there are many unknowns centered around the shape and propagation of its presynaptic AP waveform. Here, we demonstrate that the presynaptic terminal of the frog NMJ has a very brief AP waveform and that the motor nerve terminal contains three distinct electrical regions. We propose that the changes in the AP waveform as it propagates along the terminal can explain the proximal-distal gradient in transmitter release seen in electrophysiological studies.


Assuntos
Potenciais de Ação/fisiologia , Junção Neuromuscular/metabolismo , Neurotransmissores/metabolismo , Potenciais de Ação/efeitos dos fármacos , Animais , Feminino , Previsões , Masculino , Junção Neuromuscular/efeitos dos fármacos , Técnicas de Cultura de Órgãos , Rana pipiens , Bloqueadores dos Canais de Sódio/farmacologia , Fatores de Tempo
19.
Zhongguo Zhong Yao Za Zhi ; 45(5): 997-1003, 2020 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-32237438

RESUMO

To investigate the characteristics of the cold and heat properties of each resolution component of Açaí and the material basis of cooling by observing the effect of resolution components, such as Açaí oil, alcohol extract and water extract, on the neurotransmitter, endocrine hormone and immune factor level in mice with deficiency-heat and deficiency-cold syndrome. KM male mice were randomly divided into 12 groups, namely blank group, deficiency-heat model group, deficiency-heat+Açaí group, deficiency-heat+Açaí oil group, deficiency-heat+Açaí alcohol extract group, deficiency-heat+Açaí water extract group, deficiency-cold model group, deficiency-cold+Cinnamomi Cortex group, deficiency-cold+Açaí group, deficiency-cold+Açaí oil group, deficiency-cold+Açaí alcohol extract group, and deficiency-cold+Açaí water extract group. The mice in deficiency-heat group were given with thyroid tablet solution(160 mg·kg~(-1)), and the mice in deficiency-cold group were given with hydrocortisone solution(25 mg·kg~(-1)) by intragastric administration every afternoon for 14 days. The mice in each administration group received corresponding drug. The neurotransmitter, endocrine hormone and immune factor levels in the mice were measured after the experiment. The Açaí alcohol extract, consistent with the Açaí powder, showed a regulatory effect on the deficiency-heat model mice; Açaí oil and its water extract were consistent with Cinna-momi Cortex, showing a regulatory effect on the deficiency-cold model mice. In this study, on the basis of proving that Açaí was was cool in property, it also revealed that alcohol extract of Açaí was cool while oil and water extract were warm in property based on the effect of Açaí on neuro-endocrine-immune network. The results suggested that the medicine property of Açaí was the result of the comprehensive action of the resolution components with different properties, and the alcohol extract of Açaí was proved as the material basis of Açaí cold medicine by using the methods of homogeneous comparison and heterogeneous disproval.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Sistema Endócrino/efeitos dos fármacos , Euterpe/química , Sistema Imunitário/efeitos dos fármacos , Sistema Nervoso/efeitos dos fármacos , Animais , Hormônios/metabolismo , Fatores Imunológicos/metabolismo , Masculino , Camundongos , Neurotransmissores/metabolismo , Extratos Vegetais/farmacologia
20.
Chemosphere ; 254: 126715, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32334245

RESUMO

Perinatal exposure to bisphenol A (BPA) contributes to neurological disorders in offspring, but the underlying mechanisms are still poorly understood. The abnormal release of neuroactive metabolites in the tryptophan (TRP) and dopamine (DA) pathways is considered to be closely associated with some disorders. Thus, in this study, TRP and DA pathways in adult female mouse offspring were investigated when the pregnant mice were given either vehicle or BPA (2, 10, or 100 µg/kg/d) from day 6 of gestation until weaning. Then, the serum and brain samples of offspring were collected at 3, 6 and 9 months, and 12 neuroactive metabolites in the TRP and DA pathways were detected. The results showed that, in the TRP pathway, TRP levels decreased, whereas kynurenine (KYN) levels and TRP turnover increased in the brain. In the serum, TRP, KYN and 5-hydroxytryptamine (5-HT) levels decreased significantly. For the DA pathway, DA and DA metabolites, including 3,4-dihydroxyphenylacetic acid (DOPAC), 3-methoxytyramine (3-MT) and homovanillic acid (HVA), reduced significantly in the brain and serum. DA turnover decreased dramatically in the brain but enhanced in the serum. The disturbance of these two metabolic pathways might be one of the potential mechanisms of BPA-induced neuropsychiatric disorders.


Assuntos
Compostos Benzidrílicos/toxicidade , Dopamina/metabolismo , Poluentes Ambientais/toxicidade , Neurotransmissores/metabolismo , Fenóis/toxicidade , Triptofano/metabolismo , Ácido 3,4-Di-Hidroxifenilacético , Animais , Encéfalo/metabolismo , Dopamina/análogos & derivados , Feminino , Masculino , Redes e Vias Metabólicas , Camundongos , Gravidez , Serotonina/metabolismo
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