| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2005: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Research Abstract |
1. In urethane-anesthetized spontaneously-breathing rabbits, activities of sympathetic premotor neurons in the raphe nuclei were recorded extracellularly to investigate the effects of thermal stimuli applied to the preoptic area and anterior hypothalamus ( PO/AH ) on the raphe neurons. Some neurons were activated by cold stimuli and inhibited by warming. The responses were well correlated with the changes in ear skin temperature, suggesting that these neurons were involved in the cutaneous vasoconstrictor pathway. Other neurons were inhibited by cooling and activated by warming. Although the role of these neurons was not clarified, it is possible that they are involved in the sympathetic pathway innervating visceral blood vessels, because visceral blood flow responds reciprocally to cutaneous one during thermal stimuli. Some of the neurons responding to thermal stimuli had phasic activities synchronized to cardiac and/or respiratory cycles, suggesting that baroreceptor and respiratory signals, as well as thermoregulatory signals, are converged to the raphe nuclei.
2. A new spike-sorting software was developed to improve separation of multi-unit activities. In this system, all the signals crossing a threshold are analyzed to get 12 kinds of peak and valley parameters. Any pair of these parameters can be displayed as a x-y scatter plot, on which any number of spike-sorting area can be defined. Based on the scatter plot, 2-dimensional histogram can also be displayed as a 3-dimensional surface plot, which makes easier to define sorting areas and to find out overlapped area of multiple units. As a result, the system improves quality of both single-unit recordings and simultaneous multi-unit recordings.
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