Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A comparison of the clinical and pathophysiological features of postictal psychosis and brief interictal or alternating psychosis was undertaken to examine if the underlying mechanisms are distinct in these 2 conditions. A selective review of the published literature in English on epilepsy and brief psychosis was carried out. The literature indicates that even though brief postictal and alternating psychoses are considered to be separate syndromes, they have a number of similarities. It can be argued that the underlying pathomechanisms are common, with the brain's inhibitory processes in response to seizures playing a key role in the development of the psychosis. These homeostatic mechanisms manifest as electrophysiological, cerebral blood flow, and neurotransmitter and receptor changes. Both syndromes are likely to be associated with prolonged inhibition in limbic circuits, with further seizures modifying the psychosis depending upon whether it is associated with disinhibition or hypersynchrony involving enhanced inhibition. The neurotransmitter with a key role is GABA, although ionic currents, catecholamines, opiates, adenosine, glutamate, and nitric oxide play a role. Brief postictal and alternating psychoses provide an opportunity to understand the complex relationships between epilepsy and schizophrenia-like brief psychotic episodes, and this understanding can assist in their management.
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PMID:Alternating and postictal psychoses: review and a unifying hypothesis. 1733 47

Microglia has recently been regarded to be a mediator of neuroinflammation via the release of proinflammatory cytokines, nitric oxide (NO) and reactive oxygen species (ROS) in the central nervous system (CNS). Microglia has thus been reported to play an important role in the pathology of neurodegenerative disease, such as Alzheimer's disease (AD) and Parkinson's disease (PD). The pathological mechanisms of schizophrenia remain unclear while some recent neuroimaging studies suggest even schizophrenia may be a kind of neurodegenerative disease. Risperidone has been reported to decrease the reduction of MRI volume during the clinical course of schizophrenia. Many recent studies have demonstrated that immunological mechanisms via such as interferon (IFN)-gamma and cytokines might be relevant to the pathophysiology of schizophrenia. In the present study, we thus investigated the effects of risperidone on the generation of nitric oxide, inducible NO synthase (iNOS) expression and inflammatory cytokines: interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF)-alpha by IFN-gamma-activated microglia by using Griess assay, Western blotting and ELISA, respectively. In comparison with haloperidol, risperidone significantly inhibited the production of NO and proinflammatory cytokines by activated microglia. The iNOS levels of risperidone-treated cells were much lower than those of the haloperidol-treated cells. Antipsychotics, especially risperidone may have an anti-inflammatory effect via the inhibition of microglial activation, which is not only directly toxic to neurons but also has an inhibitory effect on neurogenesis and oligodendrogenesis, both of which have been reported to play a crucial role in the pathology of schizophrenia.
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PMID:Risperidone significantly inhibits interferon-gamma-induced microglial activation in vitro. 1736 22

Music, a universal art form that exists in every culture around the world, is integral to a number of social and courtship activities, and is closely associated with other creative behaviours such as dancing. Recently, neuroimaging studies have allowed researchers to investigate the neural correlates of music processing and perception in the brain. Notably, musical stimuli have been shown to activate specific pathways in several brain areas associated with emotional behaviours, such as the insular and cingulate cortex, hypothalamus, hippocampus, amygdala, and prefrontal cortex. In addition, neurochemical studies have suggested that several biochemical mediators, such as endorphins, endocannabinoids, dopamine and nitric oxide, may play a role in the musical experience. A growing body of evidence also indicates that music therapy could be useful in the clinical management of numerous neurological and psychiatric disorders. Indeed, music therapy could be effective in patients with neurodegenerative disorders, such as Alzheimer's dementia and Parkinson?s disease, as well as in psychiatric illnesses, such as schizophrenia, depression, anxiety and autism spectrum disorders. Unfortunately, there is still a shortage of rigorous scientific data supporting the clinical application of music therapy, and there is thus a need to confirm and expand the preliminary findings regarding the potential and actual effectiveness of music therapy. This need should be addressed through prospective, randomized, controlled, single-blinded investigations of the short- and long-term effects of music therapy in diverse clinical conditions.
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PMID:Neurophysiology and neurobiology of the musical experience. 1736 77

MK-801 was shown to be one of the most neurotoxic non-competitive NMDA receptor antagonists. It is known that repeated injection of MK-801 was proposed in an animal model in psychosis. The aims of this study are to investigate the contributing effect of oxidative stress in MK-801-induced experimental psychosis model, and to show that prevention of oxidative stress may improve prognosis. Furthermore, there is evidence that oxygen free radicals play an important role in the pathophysiology of schizophrenia. In this study, Wistar Albino rats were divided into three groups: 1st group: Control, 2nd group: MK-801, 3rd group: MK-801+CAPE (Caffeic acid phenethyl ester) group. MK-801 was given intraperitoneally at the dose of 0.5 mg/kg/day for 5 days. CAPE was given to the treatment group while exposed to MK-801. In control group, saline was given intraperitoneally at the same time. After 7 days, rats were killed by decapitation. Prefrontal cortex (PFC) of rats was removed for biochemical and histological analyses. As a result, malondialdehyde (MDA), protein carbonyl (PC), nitric oxide (NO) levels and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and xanthine oxidase (XO) and adenosine deaminase (AD) enzyme activities were found to be increased significantly in prefrontal cortex (PFC) of MK-801 group (p<0.0001) compared to control group. In CAPE treated rats, prefrontal tissue MDA, PC, NO levels and, GSH-Px, XO, AD enzyme activities were significantly decreased when compared to MK-801 groups (p<0.0001) whereas catalase (CAT) enzyme activity was not changed. Moreover, in the light of microscopic examination of MK-801 groups, a great number of apoptotic cells were observed. CAPE treatment decreased the apoptotic cell count in PFC. The results of this study showed that MK-801-induced neurotoxicity caused oxidative stress in PFC of rats. This experimental study may also provide some evidences for the new treatment strategies with antioxidants in schizophrenia.
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PMID:Oxidative stress in prefrontal cortex of rat exposed to MK-801 and protective effects of CAPE. 1737 54

An accumulating body of evidences point to the significance of neuroinflammation and immunogenetics in schizophrenia, characterized by increased serum concentration of several pro-inflammatory cytokines. In the central nervous system (CNS), the microglial cells are the major immunocompetent cells which release pro-inflammatory cytokines, nitric oxide (NO) and reactive oxygen species to mediate the inflammatory process. In the present study, we investigated whether or not atypical antipsychotics, namely perospirone, quetiapine and ziprasidone, would have anti-inflammatory effects on the activated microglia which may potentiate neuroprotection. All three atypical antipsychotics significantly inhibited NO generation from activated microglia while perospirone and quetiapine significantly inhibited the TNF-alpha release from activated microglia. Antipsychotics, especially perospirone and quetiapine may have an anti-inflammatory effect via the inhibition of microglial activation, which is not only directly toxic to neurons but also has an inhibitory effect on neurogenesis and oligodendrogenesis, both of which have been reported to play a crucial role in the pathology of schizophrenia.
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PMID:The effect of atypical antipsychotics, perospirone, ziprasidone and quetiapine on microglial activation induced by interferon-gamma. 1865 69

The prefrontal cortex (PFC) is believed to play an important role in the cognitive impairments observed in schizophrenia and has also been shown to be involved in the modulation of prepulse inhibition (PPI), a measure of preattentive information processing that is impaired in schizophrenic individuals. Phencyclidine (PCP), a noncompetitive inhibitor of the NMDA receptor, exerts psychotomimetic effects in humans, disrupts PPI, and causes hypofrontality in rodents and monkeys. We have previously demonstrated that interfering with the production of nitric oxide (NO) can prevent a wide range of PCP-induced behavioral deficits, including PPI disruption. In the present study, the role of NO signaling for the behavioral and biochemical effects of PCP was further investigated. Dialysate from the medial PFC of mice receiving systemic treatment with PCP and/or the NO synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME, 40 mg/kg), was analyzed for cGMP content. Furthermore, a specific inhibitor of NO-sensitive soluble guanylyl cyclase (sGC), 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (ODQ, 0.01-1 mM), was administered into the medial PFC of mice in combination with systemic injections of PCP, followed by PPI and locomotor activity testing. PCP (5 mg/kg) caused an increase in prefrontal cGMP that could be attenuated by pretreatment with the NO synthase inhibitor, L-NAME. Moreover, bilateral microinjection of the sGC inhibitor, ODQ, into the medial PFC of mice attenuated the disruption of PPI, but not the hyperlocomotion, caused by PCP. The present study shows that NO/sGC/cGMP signaling pathway in the medial PFC is involved in specific behavioral effects of PCP that may have relevance for the disabling cognitive dysfunction found in patients with schizophrenia.
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PMID:Nitric oxide signaling in the medial prefrontal cortex is involved in the biochemical and behavioral effects of phencyclidine. 1789 15

Nitric oxide (NO) is a gaseous molecule with neurotransmitter properties that is involved in numerous functions in the central nervous system (CNS), the vascular system and also in macrophages. Haplotypes of NOS1 and NOS3 genes have been shown to be associated with different psychiatric disorders such as schizophrenia and bipolar disorder. Therefore, the detection of other characteristics of nitrinergic transmission is desirable. Because nitrinergic functioning influences serotonergic transmission, a functional marker of the serotonergic transmission, the loudness dependence of auditory evoked potentials (LDAEP), can be assumed to be influenced by nitrinergic changes as well. In order to clarify the relationship between nitrinergic transmission and LDAEP, 95 healthy subjects (41 males, 54 females) underwent electrophysiological recording and blood drawing for genotyping of single nucleotide polymorphisms (SNPs) and haplotypes of the NOS1 and NOS3 genes. Interestingly, two functional SNPs in both NOS1 (G-84A_exon 1c promoter polymorphism) and NOS3 (Glu298Asp) were associated with lower LDAEP. Further studies are needed to fully clarify the relationship between nitrinergic transmission, LDAEP and complex disorders such as schizophrenia and affective disorders.
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PMID:Association of functional polymorphisms in NOS1 and NOS3 with loudness dependence of auditory evoked potentials. 1825 68

Schizophrenia encompasses, amongst other symptoms, a heavy load of cognitive dysfunctionality. Using the psychotomimetic agent, phencyclidine (PCP), we have previously found that PCP-induced disruptions of cognitive function in translational rodent models of schizophrenia are dependent on nitric oxide (NO) production. In the present study, male Sprague-Dawley rats were subjected to a Morris water maze task designed to assess cognitive flexibility (i.e. the ability to cope with an increasingly demanding cognitive task) by means of a "constant reversal learning paradigm". Experiments were conducted to evaluate the effects of the NO synthase inhibitor, L-NAME (10 mg/kg), on PCP-induced (2 mg/kg) impairments. Control animals significantly improved their learning over the first 3 consecutive days, whereas PCP-treated animals failed to show any significant learning. Pretreatment with L-NAME normalized the PCP-induced disruption of learning to control levels. These findings suggest that PCP-induced disruptions of cognitive flexibility (i.e. ability to modify behaviour according to an increasingly demanding cognitive task) are dependent upon NO production. These observations, together with accumulated clinical findings, suggest that the NO system is a potential treatment target for cognitive dysfunctions in schizophrenia.
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PMID:Nitric oxide synthase inhibition attenuates phencyclidine-induced disruption of cognitive flexibility. 1832 64

Hippocampal output is increased in affective disorders and is mediated by increased glutamatergic input via N-methyl-D-aspartate (NMDA) receptor and moderated by antidepressant treatment. Activation of NMDA receptors by glutamate evokes the release of nitric oxide (NO) by the activation of neuronal nitric oxide synthase (nNOS). The human hippocampus contains a high density of NMDA receptors and nNOS-expressing neurons suggesting the existence of an NMDA-NO transduction pathway which can be involved in the pathogenesis of affective disorders. We tested the hypothesis that nNOS expression is increased in the human hippocampus from affectively ill patients. Immunocytochemistry was used to demonstrate nNOS-expressing neurons in sections obtained from the Stanley Consortium postmortem brain collection from patients with major depression (MD, N = 15), bipolar disorder (BD, N = 15), and schizophrenia (N = 15) and from controls (N = 15). nNOS-immunoreactive (nNOS-IR) and Nissl-stained neurons were counted in entorhinal cortex, hippocampal CA1, CA2, CA3, and CA4 subfields, and subiculum. The numbers of Nissl-stained neurons were very similar in different diagnostic groups and correlated significantly with the number of nNOS-IR neurons. Both the MD and the BD groups had greater number of nNOS-IR neurons/400 microm(2) in CA1 (mean +/- SEM: MD = 9.2 +/- 0.6 and BD = 8.4 +/- 0.6) and subiculum (BD = 6.7 +/- 0.4) when compared to control group (6.6 +/- 0.5) and this was significantly more marked in samples from the right hemisphere. These changes were specific to affective disorders since no changes were seen in the schizophrenic group (6.7 +/- 0.8). The results support the current view of the NMDA-NO pathway as a target for the pathophysiology of affective disorders and antidepressant drug development.
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PMID:Expression of neuronal nitric oxide synthase in the hippocampal formation in affective disorders. 1839 56

The activation of the inflammatory/immunological response system is suggested to be related to the pathophysiology of schizophrenia. Aripiprazole is a novel atypical antipsychotic, which is a high-affinity dopamine D(2) receptor partial agonist. Atypical antipsychotics, all of which have dopamine D(2) receptor antagonism, have recently reported to have significantly inhibitory effects on interferon (IFN)-gamma-induced microglial activation in vitro. In the present study, we investigated whether or not aripiprazole also has anti-inflammatory effect on IFN-gamma-induced microglial activation. Not quinpirole, dopamine D(2) full agonist, but aripiprazole significantly inhibited the generation of nitric oxide (NO) and tumor necrosis factor (TNF)-alpha from IFN-gamma-activated microglia and suppressed the IFN-gamma-induced elevation of intracellular Ca(2+) concentrations ([Ca(2+)](i)) in murine microglial cells. Increased [Ca(2+)](i) has been reported to be required, but by itself not sufficient, for the release of NO and certain cytokines. As a result, we can speculate that aripiprazole may inhibit IFN-gamma-induced microglial activation through the suppression of IFN-gamma-induced elevation of [Ca(2+)](i) in microglia. Our results demonstrated that not only antipsychotics which have dopamine D(2) receptor antagonism but also aripiprazole have anti-inflammatory effects via the inhibition of microglial activation. Antipsychotics may therefore have a potentially useful therapeutic effect on patients with schizophrenia by reducing the microglial inflammatory reactions.
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PMID:Inhibitory effects of aripiprazole on interferon-gamma-induced microglial activation via intracellular Ca2+ regulation in vitro. 1842 30


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