Electroconvulsive seizure-induced expression change in the dentate gyrus of the hippocampus in mice as an index of the neuronal responsiveness in vivo.
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ABSTRACT: The dentate gyrus (DG) of the hippocampus is one of major targets for antidepressant treatments. Using electroconvulsive stimulation (ECS), a model of highly effective and fast-acting antidepressant therapy, here we show that neural stimulation via ECS induces rapid and lasting dematuration of granule neurons in DG. A single time of stimulation transiently reduced mature marker expression and mature synaptic functions. Repetitive stimulation converted this transient dematuration into a stable form lasting more than 1 month. We compared the activity-dependent neuronal responsiveness in the DG between a single ECS and repeated ECS.
Project description:The dentate gyrus (DG) of the hippocampus is one of major targets for antidepressant treatments. Our recent research has revealed that selective serotonin reuptake inhibitor (SSRI) treatment causes a long-lasting change in the phenotypes of mature dentate granule neurons to immature state in adult mouse DG. However, it is unknown whether this “dematuration” of DG is a common effect of antidepressant treatments and what mechanisms underlie it. Using electroconvulsive stimulation (ECS), a model of highly effective and fast-acting antidepressant therapy, here we show that neural stimulation via ECS induces rapid and lasting dematuration of granule neurons in DG. A single or few times of stimulation transiently reduced mature marker expression and mature synaptic functions. Repetitive stimulation converted this transient dematuration into a stable form lasting more than 1 month. Dematured granule neurons showed higher excitability, and an increase in GABA-mediated inhibition by the benzodiazepine diazepam prevented the lasting maintenance phase of dematuration without affecting the initial induction phase. Our study suggests that dematuration of DG is a common cellular mechanism underlying effects of different types of antidepressant treatments, and demonstrate a novel role for excitation/inhibition balance in bidirectional regulation of the state of neuronal maturation in the adult brain.
Project description:The dentate gyrus (DG) of the hippocampus is one of major targets for antidepressant treatments. Our recent research has revealed that selective serotonin reuptake inhibitor (SSRI) treatment causes a long-lasting change in the phenotypes of mature dentate granule neurons to immature state in adult mouse DG. However, it is unknown whether this M-bM-^@M-^\dematurationM-bM-^@M-^] of DG is a common effect of antidepressant treatments and what mechanisms underlie it. Using electroconvulsive stimulation (ECS), a model of highly effective and fast-acting antidepressant therapy, here we show that neural stimulation via ECS induces rapid and lasting dematuration of granule neurons in DG. A single or few times of stimulation transiently reduced mature marker expression and mature synaptic functions. Repetitive stimulation converted this transient dematuration into a stable form lasting more than 1 month. Dematured granule neurons showed higher excitability, and an increase in GABA-mediated inhibition by the benzodiazepine diazepam prevented the lasting maintenance phase of dematuration without affecting the initial induction phase. Our study suggests that dematuration of DG is a common cellular mechanism underlying effects of different types of antidepressant treatments, and demonstrate a novel role for excitation/inhibition balance in bidirectional regulation of the state of neuronal maturation in the adult brain. Mice were decapitated after the 11 times of ECS (or Sham) or 4 weeks treatment of fluoxetine (or vehicle) at a dose of 22 mg/kg. The brains were sliced and the frequency facilitation of mossy fiber synapse was measured in each sample. The samples which exhibited low frequency facilitation were selected to be used as dematured DG (n = 3) and the dentate gyrus was dissected from each sample. Total RNA was extracted by using an RNeasy micro kit (Qiagen) and the samples of the same groups were put together. From each group, 100 ng of total RNA was amplified with 3M-bM-^@M-^YIVT Express kit (Affymetrix, Inc., Santa Clara, CA, USA). All samples were hybridized to the GeneChip mouse genome 430A 2.0 array (Affymetrix, Inc.), and the microarray suite 5.0 of the Affymetrix gene chip operating software was used for the analysis of the GeneChip data.
Project description:Rationale Electroconvulsive seizure (ECS) therapy is a nonchemical treatment for depression. Since ECS up-regulates expression of c-Fos in the paraventricular nucleus of hypothalamus (PVN), the function of which is frequently influenced in depression, we hypothesized that ECS modulates functions of the PVN and contributes to its antidepressant effects. Objectives To identify gene expression changes in the mouse PVN by ECS treatment Material and methods First, we established a method to amplify nucleotides from small quantities of RNA. Mice received one shock of ECS and their brains were collected at 2 or 6 h after shock. The PVN was microdissected from dehydrated brain sections, its total RNA was extracted and microarray analysis was applied. Results At 2 h after ECS, 2.6% (589 genes) of the probes showed more than 2-fold decrease, and 0.9% (205 genes) showed more than 2-fold increase. To confirm the expression changes, genes showing differential expression with a wide range in the microarray were analyzed by qPCR. Among the genes with more than 2-fold change by ECS, down-regulated 94 genes and up-regulated 24 genes have been reported the association with anxiety, bipolar disorder or mood disorder by the Ingenuity knowledge database. The groups of down-regulated genes, which are suggested to modulate the function of the PVN or associate to psychiatric disorders, include neuropeptides (Cck), kinases (Prkcb, Prkcc, Camk2a), transcription factors (Bcl6, Tbr1), transporters (Aqp4) and others (Fmr1). Conclusion The present results indicate that ECS treatment can modulate the functions of PVN via a series of gene expression changes, and may contribute to its antidepressant effects at least in part. Mice received one shock of ECS and their brains were collected at 2 h (PVN_ECS2h_1, PVN_ECS2h_2) or 6 h after shock (PVN_ECS6h_1, PVN_ECS6h_2). The brains of sham-treated animals were collected at 2 h after treatment (PVN_sham_1, PVN_sham_2). The PVN was microdissected from dehydrated brain sections, and its total RNA was extracted. RNA samples from two or three animals were pooled to minimize the impact of biological variance. After nucleotide amplification by the ovation amplification, the gene expression profiles were obtained by the Affymetrix microarray analysis. The microarray analysis was performed twice using different sets of animals.
Project description:Rationale Electroconvulsive seizure (ECS) therapy is a nonchemical treatment for depression. Since ECS up-regulates expression of c-Fos in the paraventricular nucleus of hypothalamus (PVN), the function of which is frequently influenced in depression, we hypothesized that ECS modulates functions of the PVN and contributes to its antidepressant effects. Objectives To identify gene expression changes in the mouse PVN by ECS treatment Material and methods First, we established a method to amplify nucleotides from small quantities of RNA. Mice received one shock of ECS and their brains were collected at 2 or 6 h after shock. The PVN was microdissected from dehydrated brain sections, its total RNA was extracted and microarray analysis was applied. Results At 2 h after ECS, 2.6% (589 genes) of the probes showed more than 2-fold decrease, and 0.9% (205 genes) showed more than 2-fold increase. To confirm the expression changes, genes showing differential expression with a wide range in the microarray were analyzed by qPCR. Among the genes with more than 2-fold change by ECS, down-regulated 94 genes and up-regulated 24 genes have been reported the association with anxiety, bipolar disorder or mood disorder by the Ingenuity knowledge database. The groups of down-regulated genes, which are suggested to modulate the function of the PVN or associate to psychiatric disorders, include neuropeptides (Cck), kinases (Prkcb, Prkcc, Camk2a), transcription factors (Bcl6, Tbr1), transporters (Aqp4) and others (Fmr1). Conclusion The present results indicate that ECS treatment can modulate the functions of PVN via a series of gene expression changes, and may contribute to its antidepressant effects at least in part.
Project description:The ventromedial nucleus of the hypothalamus (VMH) is thought to a satiety center and a potential target for anti-obesity therapy. Electroconvulsive seizure (ECS) therapy is highly effective in psychiatric diseases including depression, but also implicated beneficial effects on other neurological diseases. Although it has been reported that the neurons in the VMH are strongly activated by ECS stimulation, the effect of ECS in this hypothalamic subnucleus remains unknown. To address this issue, we investigated molecular changes in the VMH in response to ECS by utilizing a method of laser-capture microdissection coupled with microarray analysis, and examined behavioral effects of ECS via VMH activation. ECS significantly induced gene expression not only immediate-early genes such as Fos, Fosb and Jun, but also Bdnf, Adcyap1, and Hrh1 in the VMH after a single or repeated stimulus.
Project description:The ventromedial nucleus of the hypothalamus (VMH) is thought to a satiety center and a potential target for anti-obesity therapy. Electroconvulsive seizure (ECS) therapy is highly effective in psychiatric diseases including depression, but also implicated beneficial effects on other neurological diseases. Although it has been reported that the neurons in the VMH are strongly activated by ECS stimulation, the effect of ECS in this hypothalamic subnucleus remains unknown. To address this issue, we investigated molecular changes in the VMH in response to ECS by utilizing a method of laser-capture microdissection coupled with microarray analysis, and examined behavioral effects of ECS via VMH activation. ECS significantly induced gene expression not only immediate-early genes such as Fos, Fosb and Jun, but also Bdnf, Adcyap1, and Hrh1 in the VMH after a single or repeated stimulus. Mice received one or 7 times shock of ECS and their brains were collected at 2 h (VMH_1stECS2h, VMH_7thECS2h) or 6 h after shock (VMH_1stECS6h, VMH_7thECS6h). The brains of sham-treated animals were collected at 2 h after treatment(VMH_sham). The VMH was microdissected from dehydrated brain sections, and its total RNA was extracted. RNA samples from two or three animals were pooled to minimize the impact of biological variance. After nucleotide amplification by the ovation amplification, the gene expression profiles were obtained by the Affymetrix microarray analysis. The microarray analysis was performed twice using different sets of animals.
Project description:Neuronal activity-dependent gene expression plays important roles in neural plasticity. We use electroconvulsive stimulation (ECS) as an in vivo model for neuronal activation to identify genes that are regulated by neuronal activity. Dentate gyri (DG) were microdissected 4 hours after sham or ECS treatment for gene expression profiling. 4 total samples were analysed (2 for each condition). Averaged expression values between sham and ECS samples were pair-wise compared.
Project description:Neurostimulation by electroconvulsive therapy is highly effective in neuropsychiatric disorders by an unknown mechanism. Microglial toxicity plays a key role in chronic neuro-inflammatory brain diseases, where there is critical shortage in therapies. To investigate the direct effect of electroconvulsive seizures (ECS) on the CNS innate immune system, we performed transcriptome analysis on spinal microglia from ECS- and sham-treated naïve mice.
Project description:Neuronal activity-dependent gene expression plays important roles in neural plasticity. We use electroconvulsive stimulation (ECS) as an in vivo model for neuronal activation to identify genes that are regulated by neuronal activity. Dentate gyri (DG) were microdissected 4 hours after sham or ECS treatment for gene expression profiling.
Project description:For major depression, the non-drug therapy Electroconvulsive therapy (ECT) treatment is highly effective and fast-acting. Despite a large and long-standing clinical use, the neurobiological mechanisms underlining ECT curative action are still poorly understood. Thanks to a genetic animal model that constitutively exhibit behavioural and biological features relevant to some aspects of major depressive disorder, here we analyse the behavioural and biological consequences of electroconvulsive stimulations (ECS), the animal model of ECT. We found that a classical ECS treatment, with 10 stimulation over 2 weeks period, has a beneficial effect on constitutive behavioural defects. We therefore compared brain and hippocampal majority proteomes from MAP6 KO mice submitted or not to electroconvulsive stimulations.