Publications by authors named "Naoki Hanaoka"

Urodele amphibians have the ability to regenerate several organs, including the brain. For this reason, the research on neurogenesis in these species after ablation of some parts of the brain has markedly progressed. However, detailed information on the characteristics and fate of proliferated cells as well as the function of newly generated neurons under normal conditions is still limited.

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Repetitive transcranial magnetic stimulation (rTMS) has recently been widely employed for the investigation of brain function and treatment of psychiatric and neurological disorders. Although high and low stimulation frequencies are assumed to activate and deactivate brain function, respectively, the optimal parameters of rTMS for treatment of depression have been determined only on the basis of their clinical efficacy. In this study, we administered a 60-s low-frequency rTMS of three grades low intensities over the right dorsolateral prefrontal cortex (DLPFC) in 10 healthy volunteers, and monitored functional changes of the contralateral DLPFC by near-infrared spectroscopy (NIRS) during and immediately after rTMS.

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The effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) over the right frontal lobe on the function of the left frontal lobe were examined by near-infrared spectroscopy (NIRS) in eleven healthy subjects. rTMS applied 5cm anterior to the motor cortex at 1 Hz and approximately 50% of the motor threshold intensity (MT) for 60 s resulted in a significantly larger decrease in the concentration of oxygenated hemoglobin ([oxy-Hb]) during the stimulation period followed by a significantly larger increase in [oxy-Hb] and a smaller decrease in the concentration of deoxygenated hemoglobin ([deoxy-Hb]) during the poststimulation baseline period than sham stimulation. These findings are interpreted as demonstrating the deactivation and activation of the left frontal cortex during and after rTMS of the right frontal cortex, respectively.

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