Toshifumi Yamamoto

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Serotonergic axons from the raphe nuclei in the brainstem project to every region of the brain, where they make connections through their extensive terminal arborizations. This serotonergic innervation contributes to various normal behaviors and psychiatric disorders. The protocadherin-alpha (Pcdha) family of clustered protocadherins consists of 14(More)
The neuronal vesicular monoamine transporter (VMAT2) is the target molecule of action of some psychostimulants, such as methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA). The present study examined the effect of antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), on VMAT2 activity by measuring adenosine(More)
Our aim was to investigate whether a defect in vesicular monoamine transporter-2 (VMAT2) activities would affect dopaminergic cell functions or not. We examined mesencephalon dopaminergic cultures prepared from VMAT2 wild-type, heterozygous or homozygous knockout (KO) 14-day-old mouse fetuses to determine the number of tyrosine hydroxylase (TH)-positive(More)
Cocaine conditioned place preference (CPP) is intact in dopamine transporter (DAT) knockout (KO) mice and enhanced in serotonin transporter (SERT) KO mice. However, cocaine CPP is eliminated in double-KO mice with no DAT and either no or one SERT gene copy. To help determine mechanisms underlying these effects, we now report examination of baselines and(More)
Repeated amphetamine administration results in behavioral sensitization. Behavioral sensitization related to abuse and/or relapse may be associated with stable changes in gene expression. To explore the participating genes, we examined the changes in gene expression levels 24 h or 21 days (long-term withdrawal period) after chronic methamphetamine (METH)(More)
The uptake of L-serine, a nonessential amino acid known to be transported by the neutral amino acid transporter system ASC, was studied in primary cultures of rat neurons and astrocytes, and compared with that in human embryonic kidney (HEK293) cells transfected with rat ASCT1 cDNA. We first cloned neutral amino acid transporter ASCT1 from rat neurons in(More)
We reported previously that low levels of nitric oxide (NO) induced cell death with properties of apoptosis, including chromatin fragmentation and condensation in undifferentiated PC12 pheochromocytoma cells. The present study demonstrates that cytotoxicity of low concentrations of NO is mediated by inhibition of mitochondrial cytochrome c oxidase and(More)
The non-essential amino acid L-serine was shown to be required to support the survival of rat cerebellar Purkinje neurons because of lack of the expression of the L-serine biosynthesis enzyme 3-phosphoglycerate dehydrogenase in them. In the present study, we investigated L-[(3)H]serine uptake in primary cultures of neurons and astrocytes from the rat(More)
Diverse protocadherins (Pcdhs), which are encoded as a large cluster (composed of alpha, beta and gamma clusters) in the genome, are localized to axons and synapses. The Pcdhs have been proposed to contribute to the generation of sophisticated neural networks and to regulate brain function. To address the molecular roles of Pcdhs in regulating individual(More)
Nitric oxide (NO), a highly reactive gaseous molecule, has been previously reported to induce apoptosis-like cell death even at a low concentration in PC12 cells. In this study, we examined NO-induced activation of members of the mitogen-activated protein kinase (MAPK) family, i.e., p38 MAPK, extracellular signal-regulated kinases (ERK1/2), and c-Jun(More)