ABSTRACT
Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder characterized by several alterations, including disorganized brain cytoarchitecture and excitatory/inhibitory (E/I) imbalance. We aimed to analyze aspects associated with the inhibitory components in ASD, using bioinformatics to develop notions about embryonic life and tissue analysis for postnatal life. We analyzed microarray and RNAseq datasets of embryos from different ASD models, demonstrating that regions involved in neuronal development are affected. We evaluated the effect of prenatal treatment with resveratrol (RSV) on the neuronal organization and quantity of parvalbumin-positive (PV+), somatostatin-positive (SOM+), and calbindin-positive (CB+) GABAergic interneurons, besides the levels of synaptic proteins and GABA receptors in the medial prefrontal cortex (mPFC) and hippocampus (HC) of the ASD model induced by valproic acid (VPA). VPA increased the total number of neurons in the mPFC, while it reduced the number of SOM+ neurons, as well as the proportion of SOM+, PV+, and CB+ neurons (subregion-specific manner), with preventive effects of RSV. In summary, metabolic alterations or gene expression impairments could be induced by VPA, leading to extensive damage in the late developmental stages. By contrast, due to its antioxidant, neuroprotective, and opposite action on histone properties, RSV may avoid damages induced by VPA.
Subject(s)
Autism Spectrum Disorder , Autistic Disorder , Prenatal Exposure Delayed Effects , Resveratrol , Valproic Acid , Animals , Autism Spectrum Disorder/metabolism , Autistic Disorder/chemically induced , Autistic Disorder/drug therapy , Autistic Disorder/genetics , Disease Models, Animal , Female , Interneurons/metabolism , Pregnancy , Prenatal Exposure Delayed Effects/chemically induced , Rats , Resveratrol/therapeutic use , Valproic Acid/adverse effectsABSTRACT
Phenylpyrazole insecticides are successful for crop protection and public hygiene by blocking gamma-aminobutyric acid (GABA)-gated chloride channels and glutamate-gated chloride (GluCl) channels. A series of novel phenylpyrazoles containing arylimine or 1-methoxyaryl groups were designed and synthesized. The addition reaction of methanol to the imines 1-11 was investigated and the cayno addition products 13-15 were obtained. The compounds 1-15 were confirmed by 1H NMR and elemental analysis. The results of bioassay indicated that some compounds exhibited comparable bioactivity to fipronil against a broad spectrum of insects such as bean aphid (Aphis craccivora), mosquito (Culex pipiens pallens), diamondback moth (Plutella xylostella) and Oriental armyworm (Mythimna separata). Especially, the foliar contact activity against bean aphid of compound 7 at 10⯵gâ¯mL-1 was 68%, the larvacidal activity against mosquito of compounds 5, 13 and 15 at 0.0025⯵gâ¯mL-1 was 100%, the larvacidal activity against diamondback moth of compounds 9 and 11 at 0.05⯵gâ¯mL-1 was 100%, the larvacidal activity against Oriental armyworm of compound 9 at 1⯵gâ¯mL-1 was 100%. The 3-cayno moiety on pyrazole ring was essential for the high insecticidal activities against bean aphid, diamondback moth and Oriental armyworm, while the 3-carbimidate moiety on pyrazole ring was crucial to the excellent high insecticidal activities against mosquito.
Subject(s)
Imines/toxicity , Insecticides/toxicity , Pyrazoles/toxicity , Animals , Drug Design , Imines/chemical synthesis , Insecta/drug effects , Insecticides/chemical synthesis , Larva/drug effects , Molecular Structure , Pyrazoles/chemical synthesis , Structure-Activity RelationshipABSTRACT
BACKGROUND: Benzofurans are heterocyclic compounds with neurotropic activity. Some have been developed for the treatment of acute and degenerative neuronal injuries. OBJECTIVE: The study aimed to evaluate the in silico binding of some promising benzofurans on the GABA receptors, and the in vivo neurotropic activity of benzofuran analogues (BZF 6-10) of gamma-aminobutyric acid (GABA) on a seizure model. METHODS: The ligands with the best physicochemical attributes were docked on two GABA receptors (the alpha-1 subunit of GABAA-R and GBR1 subunit of GABAB-R). Selected benzofuran derivatives were synthesized by a multistep procedure and characterized. To examine the neurotropic effects, mice were pretreated with different concentrations of the compounds prior to PTZ- or 4- AP-induced seizures. We assessed acute toxicity, motor behavior, and the effects on seizures. RESULTS: The tested ligands that complied with Lipinski's rule of five were tested in silico with GABAA-R (ΔG = -5.51 to -5.84 kcal/mol) at the allosteric site for benzodiazepines. They bound to a similar cluster of residues as the reference compound (gaboxadol, ΔG = -5.51 kcal/mol). Synthesis was achieved with good overall yields (42-9.7%). Two compounds were selected for biological tests (BZF-7 and rac-BZF-10) on a mouse model of seizures, induced by pentylenetetrazol (PTZ) or 4-aminopyridine (4-AP). PTZ-induced seizures are associated with GABA receptors, and those 4-AP-induced with the blockage of the delayed rectifier-type potassium channel, which promotes the release of the NMDA-sensitive glutamatergic ionotropic receptor and other neurotransmitters. The biological assays demonstrated that BZF-7 and rac-BZF-10 do not protect against seizures. Indeed, BZF-7 increased the number of PTZ-induced seizures and decreased latency time. The 4-AP model apparently showed a potentiation of seizure effects after administration of the BZF-analogues, evidenced by the incidence and severity of the seizures and reduced latency time. CONCLUSION: The results suggest that the test compounds are GABAergic antagonists with stimulatory activity on the CNS.
Subject(s)
Benzofurans/pharmacology , Central Nervous System Stimulants/pharmacology , GABA-A Receptor Antagonists/pharmacology , GABA-B Receptor Antagonists/pharmacology , Animals , Benzofurans/chemical synthesis , Benzofurans/chemistry , Benzofurans/toxicity , Central Nervous System Stimulants/chemical synthesis , Central Nervous System Stimulants/chemistry , Central Nervous System Stimulants/toxicity , GABA-A Receptor Antagonists/chemical synthesis , GABA-A Receptor Antagonists/chemistry , GABA-A Receptor Antagonists/toxicity , GABA-B Receptor Antagonists/chemical synthesis , GABA-B Receptor Antagonists/chemistry , GABA-B Receptor Antagonists/toxicity , Humans , Ligands , Male , Mice , Molecular Docking Simulation , Receptors, GABA-A/chemistry , Receptors, GABA-B/chemistryABSTRACT
l-Cysteine is an endogenous sulfur-containing amino acid with multiple and varied roles in the central nervous system, including neuroprotection and the maintenance of the redox balance. However, it was also suggested as an excitotoxic agent implicated in the pathogenesis of neurological disorders such as Parkinson's and Alzheimer's disease. l-Cysteine can modulate the activity of ionic channels, including voltage-gated calcium channels and glutamatergic NMDA receptors, whereas its effects on GABAergic neurotransmission had not been studied before. In the present work, we analyzed the effects of l-cysteine on responses mediated by homomeric GABAA ρ1 receptors, which are known for mediating tonic γ-aminobutyric acid (GABA) responses in retinal neurons. GABAA ρ1 receptors were expressed in Xenopus laevis oocytes and GABA-evoked chloride currents recorded by two-electrode voltage-clamp in the presence or absence of l-cysteine. l-Cysteine antagonized GABAA ρ1 receptor-mediated responses; inhibition was dose-dependent, reversible, voltage independent, and susceptible to GABA concentration. Concentration-response curves for GABA were shifted to the right in the presence of l-cysteine without a substantial change in the maximal response. l-Cysteine inhibition was insensitive to chemical protection of the sulfhydryl groups of the ρ1 subunits by the irreversible alkylating agent N-ethyl maleimide. Our results suggest that redox modulation is not involved during l-cysteine actions and that l-cysteine might be acting as a competitive antagonist of the GABAA ρ1 receptors.
Subject(s)
Cysteine/pharmacology , GABA-A Receptor Antagonists/pharmacology , Receptors, GABA-A/drug effects , Animals , Binding, Competitive , Chlorides/metabolism , Cystine/pharmacology , Dose-Response Relationship, Drug , Ethylmaleimide/pharmacology , Homocysteine/pharmacology , Humans , Ion Transport/drug effects , Oocytes , Patch-Clamp Techniques , RNA, Complementary/genetics , Receptors, GABA-A/physiology , Recombinant Proteins/metabolism , Xenopus laevis , gamma-Aminobutyric Acid/pharmacologyABSTRACT
We investigated the effect of heat stress (HS) on the expression of the GABA receptor in the hypothalamic-pituitary-gonadal (HPG) axis of Wenchang chickens. Real-time quantitative RT-PCR (qRT-PCR) was used to quantify the GABA receptor mRNA levels along the HPG axis of chickens under HS (40±0.5 °C) for 1-6 weeks. Our results showed that the expression of GABAA and GABAB receptor at the mRNAs levels in the tissues of HPG axis exhibited fluctuation and variability. After HS, the mRNA level of GABAA receptor was significantly reduced in the hypothalamus of 1-week-old and in the pituitary of 3-week-old chickens, but significantly increased in the pituitary of 1-, 4-, and 5-week-old chickens. The GABAB receptor mRNA level significantly declined in the hypothalamus of 1-week-old and in the pituitary of 3-week-old chickens, but was significantly upregulated in the pituitary and testis of 1- and 2-week-old chickens. At other time points, the expressions of GABAA receptor and GABAB receptor showed no significant differences compared with control group. These results indicated that the levels of GABAA receptor and GABAB receptor mRNAs varied in different tissues of the HPG axis in chickens of different ages, displaying temporal and spatial variations. GABA receptor behaved as a positively-regulated gene by HS, i.e., its mRNA was increased by HS; similarly, it was a negatively-regulated gene by HS, when its expression was reduced by HS.(AU)
Subject(s)
Animals , Heat Stress Disorders/veterinary , Chickens/abnormalities , RNA, Messenger/analysis , RNA, Messenger/isolation & purification , Polymerase Chain Reaction/methods , Polymerase Chain Reaction , Polymerase Chain Reaction/veterinaryABSTRACT
We investigated the effect of heat stress (HS) on the expression of the GABA receptor in the hypothalamic-pituitary-gonadal (HPG) axis of Wenchang chickens. Real-time quantitative RT-PCR (qRT-PCR) was used to quantify the GABA receptor mRNA levels along the HPG axis of chickens under HS (40±0.5 °C) for 1-6 weeks. Our results showed that the expression of GABAA and GABAB receptor at the mRNAs levels in the tissues of HPG axis exhibited fluctuation and variability. After HS, the mRNA level of GABAA receptor was significantly reduced in the hypothalamus of 1-week-old and in the pituitary of 3-week-old chickens, but significantly increased in the pituitary of 1-, 4-, and 5-week-old chickens. The GABAB receptor mRNA level significantly declined in the hypothalamus of 1-week-old and in the pituitary of 3-week-old chickens, but was significantly upregulated in the pituitary and testis of 1- and 2-week-old chickens. At other time points, the expressions of GABAA receptor and GABAB receptor showed no significant differences compared with control group. These results indicated that the levels of GABAA receptor and GABAB receptor mRNAs varied in different tissues of the HPG axis in chickens of different ages, displaying temporal and spatial variations. GABA receptor behaved as a positively-regulated gene by HS, i.e., its mRNA was increased by HS; similarly, it was a negatively-regulated gene by HS, when its expression was reduced by HS.
Subject(s)
Animals , Chickens/abnormalities , Heat Stress Disorders/veterinary , RNA, Messenger/analysis , RNA, Messenger/isolation & purification , Polymerase Chain Reaction , Polymerase Chain Reaction/methods , Polymerase Chain Reaction/veterinaryABSTRACT
Introducción. El vínculo materno es fundamental para el establecimiento y mantenimiento de las redes sinápticas, y el desarrollo morfofisiológico y emocional de los individuos. Los niños maltratados o rechazados son más propensos a desarrollar psicopatologías. Los modelos animales permiten una aproximación experimental a mecanismos involucrados en alteraciones ocasionadas por estrés temprano. Objetivo. Determinar si la separación materna durante la lactancia, afecta en el adulto el tamaño del cerebro y el número de células inmunorreactivas a la subunidad alfa 1 del recep-tor ácido gamma-aminobutírico: GABA-A. Métodos. Se mantuvieron ratas Wistar con ciclo invertido luz-oscuridad, sin restricciones de agua o comida. Durante la lactancia, a unas mamás les fueron separadas las crías dos veces al día y otras se mantuvieron como grupo control. El día 22 los sujetos se separaron por sexo y tratamiento. El día 60 se perfundieron con paraformaldehído, previa anestesia, y los cere-bros fueron extraídos y pesados. Para identificar el tamaño cerebral, se hicieron cinco cortes seriados de 20 µm cada 100 µm. Se tomaron fotografías y se utilizó una escala micrométrica. La inmunorreacción al receptor GABA-A se analizó en cortes de 20 µm mediante tinción por inmunohistoquímica. Resultados. En las ratas adultas, el peso cerebral total de las ratas separadas fue menor. En las hembras separadas se observó reducción estadísticamente significativa en el tamaño del hipocampo. En los machos separados se observó disminución de la marcación para la subunidad alfa1 del receptor GABA-A, en la corteza prefrontal, la amígdala y el hipocampo. Conclusiones. Estos resultados muestran que la separación materna durante la lactancia altera, en ciertas áreas cerebrales del adulto, el tamaño y la inmunorreacción al receptor GABA-A, y que estos cambios son diferentes en hembras y machos
Introduction: The maternal bond is crucial to establish and maintain synaptic networks and for morphophysiological and emotional development of individuals. Neglected or abused kids are more susceptible to develop psychopathologies. Animal models allow an experimen-tal approach to mechanisms involved in alterations due early stress. Objective:To determine if maternal separation during nursing alters brain size in adults and the amount of immunoreactive cells to alpha subunit of GABA-A receptor. Methods: Wistar rats were kept under reverse light-dark cycle with food and water ad libitum. During nursing, pups were separated from their mothers twice a day and other group was used as control. At day 22nd, subjects were separated by gender and treatment. In day 60, subjects were anesthetized and perfused with paraformaldehyde and brains were extracted and weighted. In order to identify brain size, 5 serial slides of 20 µm were made every 100 µm. Pictures were taken and micrometric scale was used. Immunoreactivity to alpha subunit of GABA-A receptor was analyzed in 20 µm slides through immunohistochemistry. Results: In adults, total brain weight of separated rats was inferior thanin the control group. Separated females showed a significant reduction of hippocampus size. In separated males a decrease of immunoreactivity to GABA-A receptor in prefrontal cortex, amygdala and hip-pocampuswas evidenced. Conclusions: These results show that maternal separation during nursing alterssize in some brain areas of adult rats, the immunoreactivity to alpha subunit of GABA-A receptor, and these changes are different between separated females and males.
Subject(s)
Animals , Anxiety , gamma-Aminobutyric Acid , Mother-Child Relations , RatsABSTRACT
Quercetin is a natural flavonoid widely distributed in plants that acts as a neuroprotective agent and modulates the activity of different synaptic receptors and ion channels, including the ionotropic GABA receptors. GABA(Aρ1) receptors were shown to be antagonized by quercetin, but the mechanisms underlying these antagonistic actions are still unknown. We have analyzed here if the antagonistic action produced by quercetin on GABA(Aρ1) receptors was related to its redox activity or due to alternative mechanism/s. Homomeric GABA(Aρ1) receptors were expressed in frog oocytes and GABA-evoked responses electrophysiologically recorded. Quercetin effects on GABA(Aρ1) receptors were examined in the absence or presence of ascorbic acid. Chemical protection of cysteines by selective sulfhydryl reagents and site directed mutagenesis experiments were also used to determine ρ1 subunit residues involved in quercetin actions. Quercetin antagonized GABA(Aρ1) receptor responses in a dose-dependent, fast and reversible manner. Quercetin inhibition was prevented in the presence of ascorbic acid, but not by thiol reagents that modify the extracellular Cys-loop of these receptors. H141, an aminoacidic residue located near to the ρ1 subunit GABA binding site, was involved in the allosteric modulation of GABA(Aρ1) receptors by several agents including ascorbic acid. Quercetin similarly antagonized GABA-evoked responses mediated by mutant (H141D)GABA(Aρ1) and wild-type receptors, but prevention exerted by ascorbic acid on quercetin effects was impaired in mutant receptors. Taken together the present results suggest that quercetin antagonistic actions on GABA(Aρ1) receptors are mediated through a redox-independent allosteric mechanism.
Subject(s)
Ascorbic Acid/pharmacology , GABA-A Receptor Antagonists/pharmacology , Quercetin/antagonists & inhibitors , Quercetin/pharmacology , Receptors, GABA-A/metabolism , Allosteric Regulation/drug effects , Animals , Dose-Response Relationship, Drug , Histidine/metabolism , Humans , Receptors, GABA-A/chemistryABSTRACT
Recently published data (Baran et al., Neurosignals 2004; 13: 290-7) have shown significantly increased activity of glutamic acid decarboxylase, the neuronal marker for gamma-aminobutyrate (GABA)-neurons, in the frontal cortex of rat brains, 6 months after kainic acid (KA) injection. In present study glutamate and GABA levels in the frontal cortex of rats in the KA (10 mg/kg, subcutaneously)-induced spontaneous recurrent seizure model of epilepsy, 6 months after the initial KA-induced seizures, were investigated. Six months after KA injection there was found a slightly reduced glutamate level in the frontal cortex (89.7 % of control), whereas the GABA level was moderately increased (119.6 % of control). The ratio GABA:glutamate level was significantly increased in the frontal cortex (134.5 % of control; P<0.001). Obtained data would indicate an enhancement of GABAergic activities in the frontal cortex in the chronic KA epileptic model. Interaction within GABAergic parameters, thus the GABAA receptors, the GABAB receptors, glutamate and GABA transporters may play a role in the modulation but also in the exertion of epileptic events in chronic KA epileptic model, which needs to be clarified.