Integrative role of medullary neurons of the cat during exercise
Integrative role of medullary neurons of the cat during exercise
复制标题
猫髓质神经元在运动过程中的整合作用
作者：
PC Nolan;TG Waldrop
在运动中观察到的协调的心血管和呼吸反应是由收缩骨骼肌产生的传入激活和起源于延髓头端的大脑区域的下行中枢驱动所调节的。尽管必须整合这两种机制，才能使心肺活动发生与运动强度成正比的变化，但人们对这种整合是如何发生的知之甚少。本研究的目的是考察延髓部位在运动驱动与心血管和呼吸系统整合中的作用。在麻醉猫上，观察了延髓腹外侧区和被盖外侧区神经元对后肢肌肉收缩(刺激L7S1腹根)和刺激模拟中枢指令(刺激下丘脑尾侧)的反应。肌肉收缩引起59%(24/41)的延髓神经元放电频率增加，其中58%(14/24)表现为即刻增加，42%(10/24)表现为延迟增加。83%(10/12)由后肢肌肉收缩快速兴奋的神经元被下丘脑刺激抑制。相反，在肌肉收缩过程中表现出放电频率延迟增加的大多数神经元要么被下丘脑刺激兴奋(5/10)，要么不受影响(4/10)。所研究的大多数延髓神经元具有与心血管、呼吸和/或交感循环有关的基本放电。这些发现表明，来自收缩肌肉和下行中枢指令的反馈都会影响到个别的延髓神经元。这与延髓神经元在整合中枢驱动和外周反射控制运动心肺反应方面的重要性是一致的。
The co‐ordinated cardiovascular and respiratory responses observed during exercise are mediated by both afferent activation arising in contracting skeletal muscles and descending central drive originating in brain regions rostral to the medulla. Even though integration of these two mechanisms must occur in order to produce alterations in cardiorespiratory activity proportional to the intensity of the exercise, little is known about how this integration occurs. The purpose of the present study was to examine the role of medullary sites in the integration of exercise drives to the cardiovascular and respiratory systems. The responses of neurons in the ventrolateral medulla and the lateral tegmental fields to contraction of hindlimb muscles (elicited by stimulation of the L7 S1 ventral roots) and to activation of simulated central command (caudal hypothalamic stimulation) were examined in anaesthetized cats. Muscular contraction evoked an increase in discharge frequency in 59% (24/41) of the medullary neurons; 58% (14/24) of these neurons excited by muscular contraction displayed an immediate increase and 42% (10/24) had a more delayed increase in discharge frequency. Eighty‐three per cent (10/12) of neurons rapidly excited by hindlimb muscle contraction were inhibited by hypothalamic stimulation. In contrast, most neurons which showed a delayed increase in discharge frequency during muscle contraction were either excited by hypothalamic stimulation (5/10) or unaffected (4/10). The majority of medullary neurons studied possessed a basal discharge related to the cardiovascular, respiratory and/or sympathetic cycles. These findings demonstrate that both feedback from contracting muscles and descending central command impinge upon individual medullary neurons. This is consistent with the idea that medullary neurons are important in integrating both the central drive and peripheral reflexes controlling the cardiorespiratory responses to exercise.
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延髓头侧腹外侧神经元介导躯体升压反射。
DOI：
10.1152/ajpregu.1989.256.2.r448
发表时间：
1989
期刊：
The American journal of physiology
影响因子：
--
作者：
Stornetta,RL;Morrison,SF;Ruggiero,DA;Reis,DJ
通讯作者：
Reis,DJ
下丘脑尾部的缺氧敏感神经元投射到导水管周围灰质。
DOI：
10.1016/0034-5687(95)00010-b
发表时间：
1995
期刊：
Respiration physiology
影响因子：
--
作者：
Ryan,JW;Waldrop,TG
通讯作者：
Waldrop,TG
肌肉收缩刺激下丘脑后部神经元。
DOI：
10.1152/ajpregu.1989.256.2.r348
发表时间：
1989
期刊：
The American journal of physiology
影响因子：
--
作者：
Waldrop,TG;Stremel,RW
通讯作者：
Stremel,RW
运动期间的心血管控制：中枢和反射神经机制。
DOI：
10.1016/0002-9149(85)91053-7
发表时间：
1985
期刊：
The American journal of cardiology
影响因子：
--
作者：
Mitchell,JH
通讯作者：
Mitchell,JH
通过下丘脑和猫收缩肌肉的反馈来控制呼吸。
DOI：
10.1016/0034-5687(86)90125-8
发表时间：
1986
期刊：
Respiration physiology
影响因子：
--
作者：
Waldrop,TG;Mullins,DC;Millhorn,DE
通讯作者：
Millhorn,DE