C-fiber depletion alters response properties of neurons in trigeminal nucleus principalis.
C-fiber depletion alters response properties of neurons in trigeminal nucleus principalis.
复制标题
C 纤维耗竭改变了三叉神经主核神经元的反应特性。
DOI：
10.1152/jn.1999.81.2.435
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发表时间：
1999
影响因子：
2.5
通讯作者：
Sessle,BJ
中科院分区：
文献类型：
--
作者：
Kwan,CL;Demaro,JA;Hu,JW;Jacquin,MF;Sessle,BJ
Kwan，C. L.，J. A.德马罗Hu，M. F. Jacquin和B. J. Sessle. C-纤维耗竭改变三叉神经主核神经元的反应特性。神经生理学杂志。81：435-446，1999。在成年大鼠中检查新生辣椒素治疗诱导的C纤维耗竭对大鼠三叉神经主核中触须敏感的低阈值机械感受（LTM）神经元的功能特性的影响。新生大鼠在出生后48小时内注射辣椒素或其载体。无髓传入纤维的耗竭被证实的辣椒素处理的大鼠后肢皮肤中诱导的伊文思蓝染料的血浆外渗的显着减少，通过皮肤应用芥子油和坐骨神经和眶下神经中的无髓纤维的显着减少。机械感受野（RF）和反应特性的31触须敏感的神经元在辣椒素处理的大鼠与32触须敏感的神经元在对照组（未处理或车辆处理）大鼠进行了比较。电子控制的机械刺激的使用允许对触须敏感神经元的响应特性进行定量分析;这些包括RF内的中心和周围RF触须的数量（即，这些触须在受到刺激时，每个刺激分别引起≥1和<1个动作电位），响应幅度和潜伏期，以及对不同方向上触须刺激的响应的选择性，重点是在向量分析中结合触须偏转的响应幅度和方向。新生儿辣椒素治疗与触须总数的显着增加，在中心RF触须每神经元RF的数量，并在触须敏感的神经元，也响应于其他类型的orofacial组织的刺激的百分比。与对照组大鼠相比，辣椒素治疗的大鼠表现出显着增加的反应幅度刺激周围RF触须以及在反应潜伏期的变化，刺激中心和周围RF触须。C-纤维耗竭也显着改变了方向的选择性反应的刺激触须。对于具有多个中心RF触须的神经元，辣椒素处理组中具有朝向同一象限的净矢量响应的中心RF触须的比例显著低于对照组。这些变化的功能特性的principalis触须敏感的神经元与显着的消耗C-纤维传入的LTM神经元研究在其他层次的啮齿动物体感系统的类似诱导的改变是一致的，确实可能有助于改变先前描述的成年啮齿动物的体感皮层。此外，这些结果提供了额外的支持，认为C纤维可能有一个重要的作用，在塑造中央躯体感觉通路的LTM神经元的功能特性。
Kwan, C. L., J. A. Demaro, J. W. Hu, M. F. Jacquin, and B. J. Sessle.C-fiber depletion alters response properties of neurons in trigeminal nucleus principalis.J. Neurophysiol.81: 435–446, 1999. The effects of C-fiber depletion induced by neonatal capsaicin treatment on the functional properties of vibrissa-sensitive low-threshold mechanoreceptive (LTM) neurons in the rat trigeminal nucleus principalis were examined in adult rats. Neonatal rats were injected either with capsaicin or its vehicle within 48 h of birth. The depletion of unmyelinated afferents was confirmed by the significant decrease in plasma extravasation of Evan's blue dye induced in the hindlimb skin of capsaicin-treated rats by cutaneous application of mustard oil and by the significant decrease of unmyelinated fibers in both the sciatic and infraorbital nerves. The mechanoreceptive field (RF) and response properties of 31 vibrissa-sensitive neurons in capsaicin-treated rats were compared with those of 32 vibrissa-sensitive neurons in control (untreated or vehicle-treated) rats. The use of electronically controlled mechanical stimuli allowed quantitative analysis of response properties of vibrissa-sensitive neurons; these included the number of center- and surround-RF vibrissae within the RF (i.e., those vibrissae which when stimulated elicited ≥1 and <1 action potential per stimulus, respectively), the response magnitude and latency, and the selectivity of responses to stimulation of vibrissae in different directions with emphasis on combining both the response magnitude and direction of vibrissal deflection in a vector analysis. Neonatal capsaicin treatment was associated with significant increases in the total number of vibrissae, in the number of center-RF vibrissae per neuronal RF, and in the percentage of vibrissa-sensitive neurons that also responded to stimulation of other types of orofacial tissues. Compared with control rats, capsaicin-treated rats showed significant increases in the response magnitude to stimulation of surround-RF vibrissae as well as in response latency variability to stimulation of both center- and surround-RF vibrissae. C-fiber depletion also significantly altered the directional selectivity of responses to stimulation of vibrissae. For neurons with multiple center-RF vibrissae, the proportion of center-RF vibrissae with net vector responses oriented toward the same quadrant was significantly less in capsaicin-treated compared with control rats. These changes in the functional properties of principalis vibrissa-sensitive neurons associated with marked depletion of C-fiber afferents are consistent with similarly induced alterations in LTM neurons studied at other levels of the rodent somatosensory system, and indeed may contribute to alterations previously described in the somatosensory cortex of adult rodents. Furthermore, these results provide additional support to the view that C fibers may have an important role in shaping the functional properties of LTM neurons in central somatosensory pathways.