DIFFERENTIAL CONTROL OF SYMPATHETIC FIBERS SUPPLYING HINDLIMB SKIN AND MUSCLE BY SUBRETROFACIAL NEURONS IN THE CAT
DIFFERENTIAL CONTROL OF SYMPATHETIC FIBERS SUPPLYING HINDLIMB SKIN AND MUSCLE BY SUBRETROFACIAL NEURONS IN THE CAT
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DOI：
10.1113/jphysiol.1988.sp016907
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发表时间：
1988-01-01
影响因子：
5.5
通讯作者：
MCALLEN, RM
中科院分区：
文献类型：
--
作者：
DAMPNEY, RAL;MCALLEN, RM
1.同时记录从节后交感神经纤维供应后肢皮肤和骨骼肌氯醛糖麻醉，人工通气猫。单纤维的活动是通过解剖分离或歧视的少数纤维制备的束在左腓浅神经或腓肠神经（支配多毛的皮肤）和腓总神经（支配肌肉）。血管收缩纤维的自发活动，以及他们的反应，腰交感神经链的刺激和压力感受器活动的变化进行了鉴定。切断双侧迷走神经、颈动脉窦神经和主动脉神经，使压力感受器失神经支配。2.在5只猫，神经元在该地区的subretrofacial核化学激活2-10 nl 0.5 M-谷氨酸钠从微量吸管插入腹侧表面的medualla。皮肤和肌肉的血管收缩纤维被激活谷氨酸注射到这一地区的两侧的髓质。动脉压也升高了。3.在42个部位注射谷氨酸引起了积极的反应，定义为皮肤和/或肌肉血管收缩纤维活性增加至少25%。这种反应仅在其中16个部位的皮肤纤维（“皮肤点”）、仅在7个部位的肌纤维（“肌肉点”）以及其余部位的两种纤维（“混合点”）中诱发。两种纤维活性的最大百分比增加是从混合点获得的。4.谷氨酸刺激肌肉穴位引起的血压升高明显大于刺激皮肤穴位引起的血压升高。对所有阳性反应的分析表明，诱发的血压升高与肌肉交感神经活动显着相关，但与皮肤交感神经活动无关。5.谷氨酸刺激不同部位可引起皮肤和肌肉血管收缩纤维的不同反应，而膈神经放电模式无任何可检测的变化。6.皮肤点集中在面后下部的内侧部分，肌肉点集中在外侧部分。此外，对于所有阳性反应，诱发的肌肉与皮肤交感神经活动的比率与距相应注射部位中线的距离之间存在高度显著的相关性。7.这些结果表明，在其相对控制交感血管收缩剂供应皮肤和骨骼肌的subretrofacial神经元之间的功能分化。此外，他们强烈建议，这样的神经元组织地形。
1. Simultaneous recordings were made from postganglionic sympathetic fibres supplying hindlimb skin and skeletal muscle in chloralose-anaesthetized, artificially ventilated cats. Single-fibre activity was either isolated by dissection or discriminated from few-fibre preparations of fascicles in the left superficial peroneal or sural nerve (innervating hairy skin) and common peroneal nerve (innervating muscle). Vasoconstrictor fibres were identified by their spontaneous activity as well as their responses to stimulation of the lumbar sympathetic chain and to changes in baroreceptor activity. The baroreceptors were then denervated by bilateral section of the vagi, carotid sinus and aortic nerves. 2. In five cats, neurones in the region of the subretrofacial nucleus were activated chemically by microinjections of 2-10 nl 0.5 M-sodium glutamate from a micropipette inserted into the ventral surface of the medualla. Both skin and muscle vasoconstrictor fibres were activated by glutamate injections into this region on either side of the medulla. Arterial pressure also rose. 3. Glutamate injections at forty-two sites evoked a positive response, defined as an increase in cutaneous and/or muscle vasoconstrictor fibre activity of at least 25%. This response was evoked only in the cutaneous fibre at sixteen of these sites (''skin points''), only in the muscle fibre at seven sites (''muscle points''), and in both fibres in the remainder (''mixed points''). The largest percentage increases in activity of either type of fibre were obtained from mixed points. 4. The blood pressure rises following glutamate stimulation of muslce points were significantly greater than those produced by stimulation of skin points. Analysis of all positive responses showed that the evoked rise in blood pressure was significantly correlated with muscle sympathetic activity but not with cutaneous sympathetic activity. 5. Glutamate stimulation at different sites could evoke differential responses in skin and muscle vasoconstrictor fibres without any detectable change in the pattern of phrenic nerve discharge. 6. Skin points were grouped in the medial part of the subretrofacial region, and muscle points in the lateral part. In addition, for all positive responses there was a highly significant correlation between the ratio of muscle to cutaneous sympathetic activity evoked, and the distance from the mid-line of the corresponding injection site. 7. These results demonstrate a functional differentiation among subretrofacial neurones in their relative control of the sympathetic vasoconstrictor supply to skin and skeletal muscle. Further, they strongly suggest that such neurones are organized topographically.