Project description:N-Methyl-D-aspartate receptors (NMDAr), widely located around the central nervous system, are known to be involved in behavioral disorders. Dizocilpine (commonly referred to as MK-801) is a well known non-competitive NMDAr antagonist. We treated rats with intraperitoneal injection [0.08 (low-dose) and 0.16 (high-dose) mg/kg] of MK-801. In one experiment, 40 min after NaCl (vehicle control) and MK-801 (0.08 mg/kg) injection, electrocorticogram (ECoG) signals were analyzed. In the second experiment, 40 min post-injection, the whole brain of each animal was rapidly removed and separated into amyglada, cerebral cortex, hippocampus, hypothalamus, midbrain and ventral striatum) on ice, followed by analysis using a 4x44K DNA microarray chip. Spectral analysis revealed that a single systemic injection of MK-801 significantly and selectively augmented the power of baseline (30-80 Hz) frequency oscillations. DNA microarray analysis showed the largest number (up- and down- regulations) of gene expressions in the cerebral cortex (378), midbrain (376), hippocampus (375), ventral striatum (353), amygdala (301), and hypothalamus (201) under low-dose of MK-801. Under high-dose, ventral striatum (811) showed the largest number of gene expression changes. Gene expression changes were functionally categorized to reveal expression of genes and function varies with each brain region. MK-801 increases the synchrony of baseline oscillations, causing very early changes in gene expressions in rat brain after acute MK-801 treatment, a first report. The overall goal of the present study was to identify gene expression patterns along rat chromosomes in different brain regions after a single injection of MK-801, which exerts a longer acute effect than ketamine on ongoing brain activities. Two approaches were taken, first electrophysiological and send molecular analysis, where the brain of MK-801-treated rats was subjected to a genome-wide transcriptome mapping analysis (~4400 genes) in the cerebral cortex, midbrain, hippocampus, ventral striatum, amygdala, and hypothalamus regions.
Project description:N-Methyl-D-aspartate receptors (NMDAr), widely located around the central nervous system, are known to be involved in behavioral disorders. Dizocilpine (commonly referred to as MK-801) is a well known non-competitive NMDAr antagonist. We treated rats with intraperitoneal injection [0.08 (low-dose) and 0.16 (high-dose) mg/kg] of MK-801. In one experiment, 40 min after NaCl (vehicle control) and MK-801 (0.08 mg/kg) injection, electrocorticogram (ECoG) signals were analyzed. In the second experiment, 40 min post-injection, the whole brain of each animal was rapidly removed and separated into amyglada, cerebral cortex, hippocampus, hypothalamus, midbrain and ventral striatum) on ice, followed by analysis using a 4x44K DNA microarray chip. Spectral analysis revealed that a single systemic injection of MK-801 significantly and selectively augmented the power of baseline (30-80 Hz) frequency oscillations. DNA microarray analysis showed the largest number (up- and down- regulations) of gene expressions in the cerebral cortex (378), midbrain (376), hippocampus (375), ventral striatum (353), amygdala (301), and hypothalamus (201) under low-dose of MK-801. Under high-dose, ventral striatum (811) showed the largest number of gene expression changes. Gene expression changes were functionally categorized to reveal expression of genes and function varies with each brain region. MK-801 increases the synchrony of baseline oscillations, causing very early changes in gene expressions in rat brain after acute MK-801 treatment, a first report.
Project description:Background: N-Methyl-D-aspartate receptors (NMDAr), widely located around the central nervous system, are known to be involved in behavioral disorders. Dizocilpine (commonly referred to as MK-801) is a well known non-competitive NMDAr antagonist. Methods: We treated rats with intraperitoneal injection [0.08 (low-dose) and 0.16 (high-dose) mg/kg] of MK-801. In one experiment, 40 min after NaCl (vehicle control) and MK-801 (0.08 mg/kg) injection, electrocorticogram (ECoG) signals were analyzed. In the second experiment, 40 min post-injection, the whole brain of each animal was rapidly removed and separated into amyglada, cerebral cortex, hippocampus, hypothalamus, midbrain and ventral striatum) on ice, followed by analysis using a 4x44K DNA microarray chip. Results: Spectral analysis revealed that a single subcutaneous injection of MK-801 significantly and selectively augmented the power of spontaneous gamma and higher-frequency oscillations. The results from DNA microarray analysis of 4400 genes showed the largest number (up- and down- regulations) of gene expressions in the cerebral cortex (378), midbrain (376), hippocampus (375), ventral striatum (353), amygdala (301), and hypothalamus (201) under low-dose of MK-801. Under high-dose, ventral striatum (811) showed the largest number of gene expression changes. These genes represented... Conclusions: Our results reveal that MK-801 triggered i) an increase in the power of gamma oscillations, and ii) simultaneously caused very early changes in gene expressions in the rat brain, representing a first such inventory of gene expression profiles in brain after acute MK-801 treatment.
Project description:Background: N-Methyl-D-aspartate receptors (NMDAr), widely located around the central nervous system, are known to be involved in behavioral disorders. Dizocilpine (commonly referred to as MK-801) is a well known non-competitive NMDAr antagonist. Methods: We treated rats with intraperitoneal injection [0.08 (low-dose) and 0.16 (high-dose) mg/kg] of MK-801. In one experiment, 40 min after NaCl (vehicle control) and MK-801 (0.08 mg/kg) injection, electrocorticogram (ECoG) signals were analyzed. In the second experiment, 40 min post-injection, the whole brain of each animal was rapidly removed and separated into amyglada, cerebral cortex, hippocampus, hypothalamus, midbrain and ventral striatum) on ice, followed by analysis using a 4x44K DNA microarray chip. Results: Spectral analysis revealed that a single subcutaneous injection of MK-801 significantly and selectively augmented the power of spontaneous gamma and higher-frequency oscillations. The results from DNA microarray analysis of 4400 genes showed the largest number (up- and down- regulations) of gene expressions in the cerebral cortex (378), midbrain (376), hippocampus (375), ventral striatum (353), amygdala (301), and hypothalamus (201) under low-dose of MK-801. Under high-dose, ventral striatum (811) showed the largest number of gene expression changes. These genes represented... Conclusions: Our results reveal that MK-801 triggered i) an increase in the power of gamma oscillations, and ii) simultaneously caused very early changes in gene expressions in the rat brain, representing a first such inventory of gene expression profiles in brain after acute MK-801 treatment. Nine male 10-weeks-old Wistar rats (300-350 g BW) were housed in acrylic cages (3/cage) at 24ºC and given access to tap water and laboratory chow ad libitum. The rats were divided into two groups, and each group rats received i.p. injection of 0.08 (low-dose) and 0.16 (high-dose) mg/kg of MK-801, respectively. Three rats were treated with saline as sham (vehicle control group) using the same method. After 40 min post-injection, the whole brain of each animal was rapidly removed and put on ice, and brain regions were separated according to the method of Glowinski and Iversen (1996), with minor modifications (Hirano et al., 2007). Each brain region was placed in a 2 mL Eppendorf tube, quickly immersed in liquid nitrogen before being stored in -80ºC prior to further analysis. Each sample was immediately weighed, flash-frozen in liquid nitrogen and stored at -80ºC prior to further analysis. A rat 4 x 44K whole genome oligo DNA microarray chip (G4131F, Agilent Technologies, Palo Alto, CA, USA) was used for global gene expression analysis. The effects of MK-801 were examined in the 6 brain reagion, Ventral striatum, Cerebral cortex, Midbrain, Amygdala, Hippocampus, and Hypothalamus.
Project description:Deciphering the molecular pathways associated with N-methyl-D-aspartate receptor (NMDAr) hypofunction and its interaction with antipsychotics is necessary to advance our understanding of the basis of schizophrenia, as well as our capacity to treat this disease. In this regard, the development of human brain-derived models amenable for studying the neurobiology of schizophrenia may contribute to fill the gaps led by the widely employed animal models. Here we assessed the proteomic changes induced by the NMDA glutamate receptor antagonist MK-801 on human brain slice cultures obtained from adult donors submitted to resective neurosurgery. Initially, we demonstrated that MK-801 diminishes NMDA glutamate receptor signaling in human brain slices in culture. Next, using mass- spectrometry-based proteomics and systems biology in silico analyses, we found that MK-801 led to alterations in proteins related to several pathways previously associated with schizophrenia pathophysiology including ephrin, opioid, melatonin, sirtuin signaling, interleukin 8, endocannabinoid and synaptic vesicle cycle. We also evaluated the impact of both typical and atypical antipsychotics on MK-801-induced proteome changes. Interestingly, the atypical antipsychotic clozapine showed a more significant capacity to counteract the protein alterations induced by NMDAr hypofunction than haloperidol. Finally, using our dataset we identified potential modulators of the MK-801-induced proteome changes, which may be considered promising targets to treat NMDAr hypofunction in schizophrenia.
Project description:Background: microRNAs (miRNAs) are small, non-coding RNAs, which can silence the expression of various target genes via binding their mRNAs, thus miRNAs serve and regulate a wide range of crucial functions in the body. However, the miRNAs expression profile after the antipsychotics mediation in schizophrenia is largely unknown. Methods: Noncompetitive N-methyl-D-aspartic acid (NMDA) receptor antagonists like as MK-801 had been shown to provide a useful animal model to investigate these effects of schizophrenia-like symptoms in rodent animals. In this study, the rat hippocampal miRNA expression profiles were examined after the antipsychotic clozapine (CLO) treated the MK-801-pretreated Sprague Dawley rats. The total RNA samples from their hippocampus of three rat groups were sequenced using next generation sequencing (NGS), then processed bioinformatic analysis. Results: Successfully, we identified 8 miRNAs’ expressions were significantly different in the MK-801 group comparing the VEH control group. Interestingly, 14 miRNAs were largely changed expression in CLO+MK-80-treated group comparing the MK-801-pretreated group, in which the rno-miR-184 was up-regulated significantly. Subsequently, further analyses suggested these miRNAs could modulate their target genes involving in the regulation of endocytosis, ubiquitin mediated proteolysis and regulation of actin cytoskeleton, which might be involved in the important mechanism of schizophrenia. Conclusion: Our results suggested the altered miRNA expressions might play an important role in the complex pathophysiology of schizophrenia, and subsequently impacted on brain functions.
Project description:The succinylome and malonylome of human oligodendrocyte precursors (MO3.13 line) and postmortem brain tissue (whole lysates and mitochondrial enrichments) were studied with shotgun mass spectrometry. The goal was to determine what changes in oligodendrocytes are induced with the addition of the NMDA receptor antagonist MK-801 and compare this with schizophrenia brain tissue; to visualize the changes that antipsychotics have on the succinylome and malonylome and how this may relate to their side effects; to see what changes induced by MK-801 are returned to more control-like levels and how this may relate to mechanisms of drug action; and to see what changes in these PTMs may exist in vivo in patients with schizophrenia compared to healthy controls.
Project description:The succinylome and malonylome of human oligodendrocyte precursors (MO3.13 line) and postmortem brain tissue (whole lysates and mitochondrial enrichments) were studied with shotgun mass spectrometry. The goal was to determine what changes in oligodendrocytes are induced with the addition of the NMDA receptor antagonist MK-801 and compare this with schizophrenia brain tissue; to visualize the changes that antipsychotics have on the succinylome and malonylome and how this may relate to their side effects; to see what changes induced by MK-801 are returned to more control-like levels and how this may relate to mechanisms of drug action; and to see what changes in these PTMs may exist in vivo in patients with schizophrenia compared to healthy controls.
Project description:d-serine is naturally present throughout the human body. It is also used as add-on therapy for treatment-refractory schizophrenia. d-Serine interacts with the strychnine-insensitive glycine binding site of NMDA receptor, and this interaction could lead to potentially toxic activity (i.e., excitotoxicity) in brain tissue. The transcriptomic changes that occur in the brain after d-serine exposure have not been fully explored. Affymetrix microarray technology was used to determine differential gene expression resulting from D-Serine exposure. Keywords: Dose course