Horn A C, Vahle-Hinz C, Brüggemann J, Petersen M, Kniffki K D
Physiologisches Institut, Universität Würzburg, Germany.
Brain Res. 1999 Dec 18;851(1-2):164-74. doi: 10.1016/s0006-8993(99)02180-0.
In seven female alpha-chloralose-anesthetized cats, 52 lateral thalamic neurons were tested with noxious distension of the urinary bladder, the distal colon and the lower esophagus. In addition, the neurons were characterized with innocuous and noxious mechanical stimulation of the skin and deep structures. Of the 52 neurons tested, 32 (62%) were visceroceptive. Of these visceroceptive neurons, 20 (63%) were located in the periphery of the ventral posterolateral nucleus (VPLp), 10 (31%) in the adjacent posterior complex (PO), and two (6%) in the ventrolateral nucleus (VL). No differences were found with respect to location between neurons responsive or unresponsive to visceral stimulation. Ten neurons (31%) received input from more than one viscus and, therefore, showed viscerovisceral convergence. Excitatory or "inhibitory" responses were elicited by stimulation of the esophagus in 21 neurons, of the colon in 13, and of the urinary bladder in 11 neurons. No indications were found for a segregation of neurons responsive to a certain viscus and their location in VPLp or PO. Of 51 neurons, for which a somatic receptive field was determined, 44 (86%) exhibited low threshold type (LT), and seven (14%) wide dynamic range type (WDR) responses. The data indicate that there might exist a somatovisceral coregistration, because many neurons (69%) had homosegmental receptive fields, and bladder stimulation was the most successful stimulus. It is concluded that VPLp and the adjacent PO in the cat play a role in the perception and localization of painful events originating from thoracic and pelvic organs.
在七只经α-氯醛糖麻醉的雌性猫中，对52个丘脑外侧神经元进行了测试，刺激因素包括膀胱、远端结肠和下食管的有害扩张。此外，还通过对皮肤和深部结构进行无害和有害的机械刺激来对这些神经元进行特征描述。在接受测试的52个神经元中，32个（62%）为内脏感觉神经元。在这些内脏感觉神经元中，20个（63%）位于腹后外侧核周边（VPLp），10个（31%）位于相邻的后复合体（PO），2个（6%）位于腹外侧核（VL）。在内脏刺激有反应和无反应的神经元之间，未发现位置上的差异。10个神经元（31%）接受来自不止一个内脏的输入，因此表现出内脏-内脏会聚。21个神经元对食管刺激产生兴奋性或“抑制性”反应，13个对结肠刺激有反应，11个对膀胱刺激有反应。未发现对某一特定内脏有反应的神经元及其在VPLp或PO中的位置存在分离现象。在确定了躯体感受野的51个神经元中，44个（86%）表现出低阈值型（LT）反应，7个（14%）表现出宽动态范围型（WDR）反应。数据表明可能存在躯体-内脏共定位，因为许多神经元（69%）具有同节段感受野，且膀胱刺激是最有效的刺激。结论是，猫的VPLp和相邻的PO在源自胸段和盆腔器官的疼痛事件的感知和定位中起作用。
