兔中缝隐核区单位放电特征及其对几种刺激的反应

ACTIVITIES OF NUCLEUS RAPHE OBSCURUS NEURONS AND THEIR RESPONSES TO SOME KINDS OF STIMULATIONS IN RABBITS

在兔延髓中缝隐核（ＮＲＯ）区用玻璃微电极引导单位放电３８３个，放电较均匀，多数幅度中等，部分放电高大，约半数的放电频率较低，均频５．４±０．３Ｈｚ，其中８．１％（３１个）的放电与呼吸节律一致。针刺“人中”穴和将兔窒息分别使８６％（４２／４９）和５４．１％（５３／９８）的放电出现反应，针刺“人中”穴和使兔窒息均在部分紧张性单位放电诱发出呼吸节律。电刺激脑桥臂旁内侧核（ＮＰＢＭ）使５７．６％（４９／８５）的单位放电出现反应，且低频放电主要表现兴奋。表明ＮＲＯ内含有一定量的呼吸相关神经元，针刺“人中”穴可部分通过改变ＮＲＯ神经元的活动发挥作用，ＮＲＯ与ＮＰＢＭ之间可能存在较直接的联系。＊Ｐ＜０．００１电均匀而稀疏，吸气性放电不呈递增型，与吸气前运动神经元放电形式不同；（３）对窒息较敏感，呈兴奋性反应。延髓内的呼吸相关神经元主要集中在背侧和腹侧呼吸组，但在其他区域也呈散在分布［５］。ＮＲＯ内的呼吸相关神经元数量不多，不呈集中分布之势。许多实验表明，针刺“人中”穴对呼吸有重要影响［６］，而针刺效应与延髓中缝核群的活动有着密切的关系［７］。我们观察到针刺“人中”穴可使呼吸兴奋，呼吸频幅均增。针刺“人中”穴使大多数ＮＲＯ?

Experiments were performed on rabbits which were urethane anesthetized, vagatomized, gallamine paralyzed and artificially ventilated. Totally 383 unit discharges were recorded extracellulary from nucleus raphe obscurus ( NRO ) area with glass microelectrode. Nearly half of the units discharges at low frequency ( 5. 4 ± 0. 3Hz ) . 8. 1 % ( 31/383 ) of the units showed respiratory rhythm. 86 % ( 42 / 49 ) units were responsive to acupuncturing the 'Renzhong' point and 54.1% ( 53/98 ) units responsed to asphyxia. Respiratory rhythm could be induced in some tonic discharges by both acupuncturing the 'Renzhong' point and asphyxia. 57. 6 % ( 49/85 )units were responsive to stimulation of NPBM ( nucleus parabrachial medialis), and the response of the low-firing-rate units was mainly excitatory.These results suggest that NRO have some respiratory-related neurons.Effects of acupuncturing the' Renzhong' point may achieved partly through changing the activities of the NRO neurons and that there are neural connections between NRO and NPBM.