| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2002: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2001: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Research Abstract |
In brainstem-spinal cord preparations isolated from newborn rats, whole cell recording technique by blind patch clamp method was applied to record membrane potentials of respiration-related neurones in the medullary respiratory rhythm generating center. Neurones recorded was marked with 0.5% neurobiotin. To examine whether the neurones marked with neurbiotin have μ-opioid receptors, immunohistochemistry of μ-opioid receptors was also performed. In the present study, we have established the whole cell recording technique in brainstem-spinal cord preparations isolated from newborn rats, and the whole cell recordings from Type I, Type II, Type III inspiratory neurones and pre-inspiratory neurones in the medullary respiration center were successfully achieved. However, these respiratroy related-neurones did not show immunoreactivity of μ-opioid receptors.
To elucidate the roles nociceptin/orphanin FQ (N/OFQ) and the nociceptin/orphanin FQ peptide (NOP) receptor (previously termed ORL1 receptor) play in the medullary structures in the generation of respiratory rhythm, the respiratory effects of N/OFQ and the NOP antagonist, Comp B were examined, using in vitro newborn rat preparations. N/OFQ reduced fR in a concentration-dependent manner. Pretreatment with CompB 10μM prevented the N/OFQ 10 nM-induced fR reduction, whereas CompB itself did not affect fR. These results show that N/OFQ acts as a neuromodulator to reduce fR in the respiratory rhythm-generating center in the medulla oblongata, and this action of N/OFQ is mediated by NOP receptors.
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