Minoru Narita

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In this study, we investigated the role of orexinergic systems in dopamine-related behaviors induced by the mu-opioid receptor agonist morphine in rodents. Extensive coexpression of tyrosine hydroxylase with orexin receptors was observed in the mouse ventral tegmental area (VTA). The levels of dopamine and its major metabolites in the nucleus accumbens were(More)
Long-term exposure to pyschostimulants and opioids induced neuronal plasticity. Accumulating evidence suggests that astrocytes actively participate in synaptic plasticity. We show here that a glial modulator propentofylline (PPF) dramatically diminished the activation of astrocytes induced by drugs of abuse, such as methamphetamine (METH) and morphine(More)
Thermal hyperalgesia and tactile allodynia induced by sciatic nerve ligation were completely suppressed by repeated intrathecal (i.t.) injection of a TrkB/Fc chimera protein, which sequesters endogenous brain-derived neurotrophic factor (BDNF). In addition, BDNF heterozygous (+/-) knockout mice exhibited a significant suppression of nerve ligation-induced(More)
Rationale: Several lines of evidence indicate that central opioid systems may be involved in the behavioral effects of nicotine. We previously reported that mecamylamine-precipitated nicotine-withdrawal aversion can be evaluated using the conditioned place preference paradigm. Objectives: In the present study, modulation of opioidergic systems in(More)
Clinically, it is well known that chronic pain induces depression, anxiety, and a reduced quality of life. There have been many reports on the relationship between pain and emotion. We previously reported that chronic pain induced anxiety with changes in opioidergic function in the central nervous system. In this study, we evaluated the anxiolytic-like(More)
Bisphenol-A has been extensively evaluated for toxicity in a variety of tests as the most common environmental endocrine disruptors. In the previous study, we reported that prenatal and neonatal exposure to high-dose of bisphenol-A affects the development of central dopaminergic system in the mouse limbic area. The present study was then undertaken to(More)
In the present study, we investigated the role of orexinergic systems in the activation of midbrain dopamine neurons. In an in vitro study, exposure to either orexin A or orexin B under superfusion conditions produced a transient increase in the intracellular Ca(2+) concentration through the phospholipase C (PLC)/protein kinase C (PKC) pathway via(More)
The present study was designed to ascertain the role of dopamine D3 receptors in the development of physical dependence on ethanol using mice lacking the dopamine D3 receptor gene. The mutation eliminated the dopamine D3 receptor without any detectable changes in both dopamine D1 and D2 receptors. The ethanol-induced sleep time in dopamine D3 receptor(More)
The present study was undertaken to evaluate the implication of delta-opioid receptor function in neurogenesis and neuroprotection. We found that the stimulation of delta-opioid receptors by the selective delta-opioid receptor agonist SNC80 [(+)-4-[(alphaR)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N,N-diethylbenzamide] (10 nm)(More)
Bisphenol-A (BPA), one of the most common environmental endocrine disrupters, has been evaluated extensively for toxicity and carcinogenicity. However, little is still known about its action on the central nervous system (CNS). In the previous study, we found that prenatal and neonatal exposure to BPA markedly enhanced the rewarding effect induced by(More)