Myelinated primary afferents of the sacral spinal cord responding to slow filling and distension of the cat urinary bladder.
Myelinated primary afferents of the sacral spinal cord responding to slow filling and distension of the cat urinary bladder.
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骶脊髓的有髓初级传入神经对猫膀胱的缓慢充盈和扩张做出反应。
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
M. Koltzenburg
中科院分区：
文献类型：
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作者：
H. Häbler;W. Jänig;M. Koltzenburg
1.从麻醉猫骶神经根S2共记录了65个骶传入神经元，其中有髓纤维供应膀胱。所有的传入单位确定与骨盆神经的电刺激。使用1 - 2 ml min-1速率的缓慢充盈和等渗扩张至预设压力水平，定量评价放电特性。在膀胱急性骶部去传出之前和之后研究了8种传入神经。2.所有传入单位沉默时，膀胱是空的，并以分级的方式增加膀胱内压。在缓慢充盈过程中，传入活动的水平与膀胱内压的水平密切相关。所有的传入表现得像缓慢适应机械感受器，其放电的动态和静态组件。除两个单位外，腔内压力阈值低于25 mmHg。因此，几乎所有的有髓传入神经都在无痛排尿周期中达到的压力范围内做出反应。3.无论膀胱内压是通过缓慢充盈还是通过扩张增加，传入神经的刺激反应功能都是相似的。然而，在缓慢充盈期间，刺激反应功能通常在5和25 mmHg之间表现出较陡的斜率，表明膀胱内压的相对较小的变化导致传入活动的较大变化。然而，所有单位显示单调增加的刺激反应功能在整个无害和有害的压力水平。4.传入神经元的刺激反应功能在膀胱急性去传出后没有改变，尽管在正常条件下由膀胱的小收缩产生的传入活动的快速阶段性波动基本上消失了。这意味着收缩和扩张通过共同的机制激活传入末梢。5.它的结论是，有髓神经骶传入的膀胱形成一个同质的人口编码的所有必要的信息，这个器官的正常调节。此外，这组传入神经介导在正常排尿周期内可能到达意识的所有感觉。
1. A total of sixty‐five sacral afferent neurones with myelinated fibres supplying the urinary bladder was recorded from the sacral roots S2 in anaesthetized cats. All afferent units were identified with electrical stimulation of the pelvic nerve. The discharge properties were quantitatively evaluated using slow filling at rates of 1‐2 ml min‐1 and isotonic distension to preset pressure levels. Eight afferents were studied prior to and after acute sacral de‐efferentation of the urinary bladder. 2. All afferent units were silent when the bladder was empty and responded in a graded manner to an increase of intravesical pressure. During slow filling the level of afferent activity correlated closely with the level of the intravesical pressure. All afferents behaved like slowly adapting mechanoreceptors with both a dynamic and static component of their discharge. With the exception of two units the intraluminal pressure threshold was below 25 mmHg. Thus virtually all myelinated afferents respond in the pressure range that is reached during a non‐painful micturition cycle. 3. The stimulus‐response functions of the afferents were similar regardless of whether intravesical pressure was increased by slow filling or by distension. However, during slow filling stimulation response functions often exhibited steeper slopes between 5 and 25 mmHg indicating that relatively small changes of intravesical pressure result in large changes of afferent activity. Nevertheless, all units displayed monotonically increasing stimulus response functions throughout the innocuous and noxious pressure level. 4. The stimulus‐response functions of the afferent neurones did not change after acute de‐efferentation of the urinary bladder, although the rapid phasic fluctuations of afferent activity that are produced by small contractions of the urinary bladder under normal conditions largely disappeared. This means that contractions and distension activate the afferent endings by a common mechanism. 5. It is concluded that the myelinated sacral afferents of the urinary bladder form a homogeneous population which encodes all information necessary for the normal regulation of this organ. Furthermore, this set of afferents mediates all sensations which may reach consciousness within a normal micturition cycle.