Wedekind C
Department of Neurosurgery, University of Cologne, Germany.
Somatosens Mot Res. 1997;14(4):229-36. doi: 10.1080/08990229770962.
We investigated the physiological properties of mediastinal pleural primary afferent units by recording single nerve fibre activity from the phrenic nerve in an in vitro preparation of rabbit tissue. A total of 41 units with conduction velocities in the group III and IV range were examined for their responsiveness to mechanical, thermal and chemical stimuli. Most receptive fields were adjacent to the phrenic nerve-pericardiacophrenic artery complex. The thresholds to punctate mechanical stimulation (von Frey hairs) were widely scattered around a median of 5.4 mN; all fibres showed slowly adapting responses to mechanical stimulation. Heat sensitivity was observed in 7/41 units (17%), while 17/41 (41%) of the fibres exhibited a spurious transient excitation to strong and rapid cooling. Chemosensitivity was scarce with respect to capsaicin (7/33 (21%) of the units responding) but more common to CO2-saturated synthetic interstitial fluid (pH 6.1, 5/16 (31%) responding). The most effective stimulus was a mixture of bradykinin, serotonin, histamine and prostaglandin E2 ('inflammatory soup') which evoked stimulus responses in 27/33 (82%) of the afferent fibres challenged. Sensitization to mechanical stimuli occurred in 5/41 (12%) of the units, following the application of heat or inflammatory mediators. The rabbit pleura appears as a tissue mainly innervated by multimodal mechano- and chemosensitive afferent units.
我们通过在兔组织的体外制备中记录膈神经的单纤维活动，研究了纵隔胸膜初级传入单位的生理特性。总共检查了41个传导速度在III和IV组范围内的单位，以检测它们对机械、热和化学刺激的反应性。大多数感受野与膈神经-心包膈动脉复合体相邻。点状机械刺激（von Frey毛）的阈值广泛分布在中位数5.4 mN左右；所有纤维对机械刺激均表现出慢适应反应。在41个单位中有7个（17%）观察到热敏感性，而41个纤维中有17个（41%）对强烈快速冷却表现出假的瞬态兴奋。对辣椒素的化学敏感性较低（33个单位中有7个（21%）有反应），但对二氧化碳饱和的合成组织间液（pH 6.1，16个中有5个（31%）有反应）更为常见。最有效的刺激是缓激肽、5-羟色胺、组胺和前列腺素E2的混合物（“炎症介质汤”），在33个受挑战的传入纤维中有27个（82%）引起刺激反应。在施加热或炎症介质后，41个单位中有5个（12%）出现对机械刺激的敏感化。兔胸膜似乎是一个主要由多模式机械和化学敏感传入单位支配的组织。
