Hiroyuki Watanabe

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BACKGROUND Because researchers have reported that antidepressants increase the expression of brain-derived neurotrophic factor (BDNF) in the rat hippocampus, we investigated whether serum BDNF levels may be used as a putative biological marker for major depressive disorders (MDD). METHODS We measured serum BDNF in the following three groups:(More)
TRPV4 is a widely expressed cation channel of the 'transient receptor potential' (TRP) family that is related to the vanilloid receptor VR1 (TRPV1). It functions as a Ca2+ entry channel and displays remarkable gating promiscuity by responding to both physical stimuli (cell swelling, innoxious heat) and the synthetic ligand 4alphaPDD. An endogenous ligand(More)
We have studied activation by phorbol derivatives of TRPV4 channels, the human VRL-2, and murine TRP12 channels, which are highly homologous to the human VR-OAC, and the human and murine OTRPC4 channel. 4alpha-Phorbol 12,13-didecanoate (4alpha-PDD) induced an increase in intracellular Ca(2+) concentration, [Ca(2+)](i), in 1321N1 cells stably transfected(More)
We have compared activation by heat of TRPV4 channels, heterogeneously expressed in HEK293 cells, and endogenous channels in mouse aorta endothelium (MAEC). Increasing the temperature above 25 degrees C activated currents and increased [Ca(2+)](i) in HEK293 cells transfected with TRPV4 and in MAEC. When compared with activation of TRPV4 currents by the(More)
Aquaporin-1 (AQP1) is a water channel expressed strongly at the ventricular-facing surface of choroid plexus epithelium. We developed novel methods to compare water permeability in isolated choroid plexus of wild-type vs. AQP1 null mice, as well as intracranial pressure (ICP) and cerebrospinal fluid (CSF) production and absorption. Osmotically induced water(More)
Aquaporin-4, the major water-selective channel in astroglia throughout the central nervous system, facilitates water movement into and out of the brain. Here, we identify a novel role for aquaporin-4 in astroglial cell migration, as occurs during glial scar formation. Astroglia cultured from the neocortex of aquaporin-4-null mice had similar morphology,(More)
The role of inferencing with uncertainty is becoming more important in rule-based expert systems (ES), since knowledge given by a human expert is often uncertain or imprecise. We have succeeded in designing a VLSI chip which can perform an entire inference process based on fuzzy logic. The design of the VLSI fuzzy inference engine emphasizes simplicity,(More)
BACKGROUND The hypofunction of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors has been implicated in the pathophysiology of schizophrenia. Several lines of evidence suggest that D-serine may function as an endogenous agonist of the glycine site of the NMDA receptor. The aim of this study was to examine whether serum levels of D- and L-serine(More)
We have studied the molecular determinants of ion permeation through the TRPV4 channel (VRL-2, TRP12, VR-OAC, and OTRPC4). TRPV4 is characterized by both inward and outward rectification, voltage-dependent block by Ruthenium Red, a moderate selectivity for divalent versus monovalent cations, and an Eisenman IV permeability sequence. We identify two(More)
We have studied the modulation of gating properties of the Ca2+-permeable, cation channel TRPV4 transiently expressed in HEK293 cells. The phorbol ester 4alphaPDD transiently activated a current through TRPV4 in the presence of extracellular Ca2+. Increasing the concentration of extracellular Ca2+ ([Ca2+](e)) reduced the current amplitude and accelerated(More)