Hidetsugu Okada

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To find a novel human ion channel gene we have executed an extensive search by using a human genome draft sequencing data base. Here we report a novel two-pore domain K+ channel, TRESK (TWIK-related spinal cord K+ channel). TRESK is coded by 385 amino acids and shows low homology (19%) with previously characterized two-pore domain K+ channels. However, the(More)
We microneurographically recorded muscle sympathetic nerve activity (MSA) during sleep in 12 healthy volunteers while simultaneously recording EEG, EOG, ECG, respiration, and blood pressure and determined the number of pulse-synchronous MSA bursts per minute (burst rate) for non-rapid eye movement (nonREM) sleep and rapid eye movement (REM) sleep. MSA(More)
Spontaneous correlated activity regulates the precision of developing neural circuits. A synchronized elevation of intracellular calcium ion concentration, [Ca(2+)](i), occurred in 5-50 adjacent neurons--known as a "neuronal domain"--in developing neocortex. This coordinated response of neuronal cells is mediated by the diffusion of inositol trisphosphate(More)
To characterize the features of sympathetic nerve activity during non-REM sleep, we measured the muscle and skin sympathetic nerve activities (MSNA and SSNA, respectively) using a double recording microneurographic technique. Eight healthy volunteers were monitored by polysomnography (including EEG, EOG, EMG, and ECG) and received acoustic stimuli (880 Hz,(More)
Skin sympathetic nerve activity (SSNA) from the tibial nerve and event-related brain potentials (ERPs) were recorded simultaneously during auditory oddball paradigms with a counting task in 10 healthy subjects to elucidate the relationships between the autonomic nervous system and the cognitive process. After the target tones. SSNA bursts were observed more(More)
The NMDA receptor (NMDAR) is a Ca (2+)-permeable cation channel that plays a critical role in neural network formation during brain development. Since it is blocked in a voltage-dependent manner by extracellular Mg(2+), in order for the NMDA to be activated, the membrane must be strongly depolarized. Immature neurons in the developing neocortex can be(More)
The purpose was to investigate the relationship between dream-recall frequency and waking imagery, so 323 undergraduates completed four imagery tests: (1) Sheehan's modified version of Betts' Questionnaire on Mental Imagery, (2) Marks' Vividness of Visual Imagery Questionnaire, (3) the Gordon Test of Visual Imagery Control, (4) Richardson's Verbalizer(More)
The purpose of the present study was to clarify how the regional differentiation of sympathetic nerve activity (SNA) is modified during natural sleep in humans. In humans, muscle and skin sympathetic nerve activities (MSNA, SSNA) have been reported to discharge independently according to a regional differentiation of SNA during wakefulness. However, in(More)
We have cloned a transient type K channel from rat heart (RH10) and coexpressed a metabotropic glutamate receptor (mGluR5) to study the functional modulation of RH10 coupled to the phosphatidylinositol (PI) hydrolysis. Stimulation of mGluR5 suppressed peak amplitude of RH10 current and affected voltage dependence of activation and inactivation of the(More)
We constructed tandem cDNA by linking the 5' end of a delayed rectifier-type (Kv1.2) clone to the 3' end of a transient-type (Kv1.4) K+ channel clone. Fusion genes were also constructed, consisting of Kv1.4 and mutants of Kv1.2, which have a single amino acid substitution in the S4-S5 loop. From electrophysiological characterization, it is likely that two(More)
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