Nihon shinkei seishin yakurigaku zasshi = Japanese journal of psychopharmacology最新文献

Cell positioning and neuronal network formation are crucial for proper brain function. Disrupted-In-Schizophrenia 1 (DISC1) is anterogradely transported to the neurite tips, together with Lis1, and functions in neurite extension via suppression of GSK3β activity. Then, transported Lis1 is retrogradely transported and functions in cell migration. Here, we show that DISC1-binding zinc finger protein (DBZ) regulates mouse cortical cell positioning and neurite development in vivo, together with DISC1. DBZ hindered Ndel1 phosphorylation at threonine 219 and serine 251. DBZ depletion or expression of a double-phosphorylated mimetic form of Ndel1 impaired the transport of Lis1 and DISC1 to the neurite tips and hampered microtubule elongation. Moreover, application of DISC1 or a GSK3β inhibitor rescued the impairments caused by DBZ insufficiency or double-phosphorylated Ndel1 expression. We concluded that DBZ controls cell positioning and neurite development by interfering with Ndel1 from disproportionate phosphorylation, which is critical for appropriate anterograde transport of the DISC1-complex.

Oxidative stress and neuroinflammation have recently been focused on the pathological hypotheses of schizophrenia. N-acetylcysteine (NAC) is a precursor of endogenous antioxidant glutathione and has antioxidant, anti-inflammatory, and neuroprotective properties. NAC is widely available as an over-the-counter nutritional supplement. Increasing lines of evidence suggest that NAC is effective for various mental disorders. In randomized controlled trials, treatment with NAC as an add-on to antipsychotics showed beneficial effects and safety profiles in patients with chronic schizophrenia. The results of a recent preclinical study using a neurodevelopmental model of schizophrenia suggest that NAC may have promising effects in an early stage of schizophrenia and an at-risk mental state. However, there is little clinical evidence for the efficacy and safety of NAC at these stages of schizophrenia. In this review, we summarize the evidence regarding the effectiveness of NAC for the treatment of schizophrenia and its prodromal stage. We also introduce the preliminary results of our research on NAC.

The prevailing view is that both glutamic (Glu) and gamma-aminobutyric (GABA) acids play a role as an amino acid neurotransmitter released from neurons. However, little attention has been paid to the possible expression and functionality of signaling machineries required for amino acidergic neurotransmission in cells other than central neurons. In line with our first demonstration of the presence of Glu receptors outside the brain, in this review I will outline our recent findings accumulated since then on the physiological and pathological significance of neuronal amino acids as an extracellular signal essential for homeostasis in a variety of phenotypic cells. In undifferentiated neural progenitor cells, for instance, functional expression is seen with different signaling machineries used for glutamatergic and GABAergic neurotransmission in neurons. Moreover, Glu plays a role in mechanisms underlying suppression of proliferation for self-replication in undifferentiated mesenchymal stem cells. There is more accumulating evidence for neuronal amino acids playing a role as an extracellular autocrine or paracrine signal commonly used in different phenotypic cells. Evaluation of drugs currently used could be thus beneficial for the efficient prophylaxis and/or the therapy of a variety of diseases relevant to disturbance of amino acid signaling in diverse organs.

Optogenetics is a recently developed experimental technique to control the activity of neurons using light. Optogenetics shows its power to reveal the physiological role of specific neural circuits in the brain. In particular, manipulation of a specific type of neurons using optogenetics with high accuracy timing enables us to analyze causality between neural activity and initiation of animal behaviors. However, to manipulate the activity of specific neurons in vivo, there are two critical steps to succeed in manipulation of the neural activity and control of the behavior of individual animals. The first step is an adequate number of molecules of light-activated protein that has to be expressed in the cell membrane of the neurons of interest. The second step is the optical system to illuminate the targeted neurons with enough intensity of light to activate the light-activated protein. We applied optogenetics to hypothalamic peptidergic neurons such as orexin/hypocretin neurons or melanin concentrating hormone (MCH) neurons. These neurons are implicated in sleep/wakefulness regulation. In this mini review, I will show the regulatory mechanism of sleep/wakefulness by these neurons using optogenetics.

Organisms living outside of tropical zones experience seasonal changes in environment. Organisms are using day length as a calendar to change their physiology and behavior such as seasonal breeding, hibernation, migration, and molting. A comparative biology approach revealed underlying mechanisms of vertebrate seasonal reproduction. Here we review the current understanding of vertebrate seasonal reproduction. We Aso describe the involvement of tissue-specific post-translational modification in functional diversification of a hormone.

Genetic factors are involved in determinants for the risk of psychiatric disorders, and neurological and neurodegenerative diseases. Chronic pain stimuli and intense pain have effects at a cellular and/or gene expression level, and will eventually induce "cellular memory due to pain", which means that tissue damage, even if only transient, can elicit epigenetically abnormal transcription/translation and post-translational modification in related cells depending on the degree or kind of injury or associated conditions. Such cell memory/transformation due to pain can cause an abnormality in a fundamental intracellular response, such as a change in the three-dimensional structure of DNA, transcription, or translation. On the other hand, pain is a multidimensional experience with sensory-discriminative and motivational-affective components. Recent human brain imaging studies have examined differences in activity in the nucleus accumbens between controls and patients with chronic pain, and have revealed that the nucleus accumbens plays a role in predicting the value of a noxious stimulus and its offset, and in the consequent changes in the motivational state. In this review, we provide a very brief overview of a comprehensive understanding of chronic pain associated with emotional dysregulation due to transcriptional regulation, epigenetic modification and miRNA regulation.

Schizophrenia and bipolar disorder show high comorbidity with smoking dependence. Several previous studies reported that glycogen synthase kinase 3β (GSK3β), which is widely expressed in the brain including the dopamine projection areas such as the amygdala, nucleus accumbens and hippocampus, may play a role in neuropsychiatric disorders and dopamine- and serotonin-mediated behavior. In this study, we have analyzed the association of three single nucleotide polymorphisms (SNPs) within GSK3β gene (rs3755557, rs334558, rs6438552) with the smoking habits and age at smoking initiation in a sample of 384 young adult Japanese, which included 172 smokers and 212 non-smokers. As a result, rs334558 was significantly associated with smoking habits in genotype frequency and allelic frequency (P < 0.05). Furthermore, higher haplotype 3 (T-T-T) and haplotype 5 (A-T-C) frequencies were observed in non-smokers than smokers (P < 0.05). Three functional polymorphisms examined in this study reportedly increase transcriptional activity when they have a high-activation allele such as the A allele of -1727A/T (rs3755557), the T allele of -50T/C (rs334558) or T allele of -157T/C (rs6438552). Thus, it was suggested in this study that changes in GSK3β activity may have an impact on smoking habits.

The pathogenesis of neuropathic pain is quite complicated and diverse. Because pre-existing analgesics, such as opioid analgesics and nonsteroidal anti-inflammatory drugs, are not sufficient to treat it, it is a serious task to establish a strategy of remedy for neuropathic pain. Recently, increasing evidence suggests that immune cell-mediated neuroinflammation in the nervous system induces central and peripheral sensitization, resulting in chronic pain. Initially, the immune system plays an important role in host defense. Although intravital homeostasis is kept constant by innate and adaptive immunity, the immune system is activated excessively due to infection, stress and tissue injury. Activated immune cells produce and release several kinds of inflammatory mediators, which act directly on sensory neurons and promote a recruitment of immune cells, developing the feedback loop of inflammatory exacerbation. We've focused on the role of crosstalk between immune cells and neurons in peripheral neuroinflammation, and explored a novel candidate for a remedy of neuropathic pain. In this review, we will introduce recent reports and our research work that suggest the functional significance of neuroinflammation in neuropathic pain, and survey possibilities of new strategies for chronic pain from the point of view of basic research.