本研究是想探究延腦黑暗縫合核(nucleus raphe obscurus; NRO)是否含有
與呼吸有關的神經元,並觀察其對二氧化碳濃度改變或電刺激迷走神經傳入
纖維的反應。經去大腦.麻痺.切斷兩側迷走神經後,以人工呼吸器維持通氣,
呼氣末氣體濃度維持在高氧及二氧碳濃度正常。分離並記錄膈神經活動。
以金屬微電極記錄NRO神經元的反應。
在所記錄的120個神經元中,與呼吸有關的神經元有53個,佔44.1%,可分為呼
氣神經元(E).吸氣呼氣神經元(IE).呼氣吸氣神經元(EI)及連續性呼氣吸氣
神經元(T-EI).連續性吸氣呼氣神經元(T-IE)等,其中以EI及T-EI所佔比例
較高,其次是IE與T-IE。在53個神經元中,有40個接受二氧化碳濃度升高的
測試,結果有18個神經元放電率降低(p<0.05),8個放電率升高,其餘反應不
規則。又電刺激迷走神經傳入纖維則發現,在13個與呼吸有關神經元中,
有9個神經元放電率降低(p<0.05),另3個則升高,1個不受影響。
這些結果顯示,延腦黑暗縫合核的呼吸神經元會受到化學接受器與迷走神經
傳入纖維之調節,且這些呼吸神經元對呼吸管制也可能扮演一個重要角色。

The purpose of this work was to examine whether respiratory-
related neurons are existed in the nucleus raphe obscurus (NRO)
and their response to hypercapnia and vagal afferent stimulation.
Cats were decerebrated, paralyzed, vagotomized and ventilated.
End-tidal fractional concentration of CO2 (FETCO2) was maintained
at hyperoxic normocapnia. The phrenic nerve was isolated and its
activity was monitored. Single unit activity within the NRO was
recorded with metal microelectrode. Activity of the neuron was
evaluated in response to hypercapnia or vagal afferent excitation.
Fifty three of 120 neurons recorded showed respiratory-related
activities. They were classified as expiratory-inspiratory (EI),
inspiratory-expiratory (IE), tonic inspiratory-expiratory(T-IE)
and tonic expiratory-inspiratory (T-EI) and expiratory (E) patterns
according to the phrenic discharge. Forty of those respiratory-
related neurons were tested their response to hypercapnia. Eighteen
of them reduced their discharge rate (p<0.05) whereas eight enchanced.
The remainders displayed irregular respone. With vagal stimulation,
nine of 13 neurons reduced their discharge rate (p<0.05), three
elevated, and the other one were unaffected.
These results indicate that respiratory-related neurons within
the NRO can be modulated by the inputs from the chemoreceptor and
vagal afferents. It also suggest that the NRO may play a role in
the regulation of respiration.
The purpose of this work was to examine whether respiratory-