Qin Chao, Chandler Margaret J, Foreman Robert D, Farber Jay P
Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73190, USA.
J Neurophysiol. 2002 Nov;88(5):2215-23. doi: 10.1152/jn.00120.2002.
The aim of this study was to determine if thoracic respiratory interneurons (TRINs) might receive peripheral noxious somatic and visceral inputs. Extracellular potentials of 78 respiration-related T(3) neurons, whose activity was driven by central respiratory output, were recorded from the intermediate zone in pentobarbital anesthetized, paralyzed, and ventilated male rats. These neurons were identified as interneurons by their locations and by the absence of antidromic activation from the cervical sympathetic trunk and cerebellum. Thoracic esophageal distension (ED) was produced by water inflation of a latex balloon (0.1-0.5 ml, 20 s). A catheter was placed in the pericardial sac to administer 0.2 ml bradykinin (10(-5) M) for noxious cardiac stimulation. Of 78 TRINs examined for ED, activity of 24 TRINs increased and activity of 8 TRINs decreased. Intrapericardial bradykinin increased activity in 26/65 TRINs tested and decreased activity in 5 TRINs. Seventy-four TRINs were tested for effects of brush, pressure, and pinch of the chest and upper back areas. No TRINs responded to brushing hair. Low-threshold responses to pressure were observed in 27 TRINs. Fourteen TRINs were wide dynamic range and 4 TRINs had high-threshold responses. Peripheral stimuli affected all types of TRINs, including inspiratory, expiratory, and biphasic neurons. Simultaneous phrenic recordings showed that effects of various somatic and visceral stimuli on TRINs were independent of central respiratory drive. Various somatovisceral and viscerovisceral patterns of input were observed in TRINs. The results suggested that TRINs participate in intraspinal processing and integration of nociceptive information from somatic fields and visceral organs.
本研究的目的是确定胸段呼吸中间神经元（TRINs）是否可能接受外周有害的躯体和内脏传入。在戊巴比妥麻醉、麻痹并通气的雄性大鼠的中间带记录了78个与呼吸相关的T(3)神经元的细胞外电位，其活动由中枢呼吸输出驱动。这些神经元通过其位置以及来自颈交感干和小脑的逆向激活缺失而被鉴定为中间神经元。通过向乳胶气球内充水（0.1 - 0.5 ml，20 s）来产生胸段食管扩张（ED）。将一根导管置于心包腔内以注入0.2 ml缓激肽（10⁻⁵ M）用于有害性心脏刺激。在接受ED检测的78个TRINs中，24个TRINs的活动增加，8个TRINs的活动减少。心包内注入缓激肽使65个受试TRINs中的26个活动增加，5个活动减少。对74个TRINs测试了胸部和上背部区域的刷擦、按压和捏夹的影响。没有TRINs对刷擦毛发有反应。在27个TRINs中观察到对压力的低阈值反应。14个TRINs为宽动态范围，4个TRINs有高阈值反应。外周刺激影响所有类型的TRINs，包括吸气、呼气和双相神经元。同时记录膈神经表明，各种躯体和内脏刺激对TRINs的影响独立于中枢呼吸驱动。在TRINs中观察到了各种躯体 - 内脏和内脏 - 内脏的输入模式。结果表明TRINs参与脊髓内来自躯体区域和内脏器官的伤害性信息的处理和整合。
