Gold Michael S, Traub Richard J
Department of Biomedical Sciences, University of Maryland Dental School, Dept. BMS, Room 5-A-12 HHH, 666 West Baltimore Street, Baltimore, MD 21201, USA.
J Neurophysiol. 2004 Jun;91(6):2524-31. doi: 10.1152/jn.00866.2003. Epub 2004 Jan 21.
This study was designed to test the hypotheses that pain syndromes associated with specific body regions reflect unique properties of sensory neurons innervating these regions and/or unique responses of these afferents to tissue damage. Acutely dissociated adult rat dorsal root ganglia (DRG) neurons retrogradely labeled from either the colon or the glabrous skin of the hindpaw were studied by whole cell patch-clamp recording in current-clamp mode. Two populations of colonic afferent neurons were studied: pelvic afferents (arising from L(6), S(1), and S(2) DRG = LS DRG) and hypogastric/lumbar colonic afferents (arising from T(13), L(1), and L(2) DRG = TL DRG). Passive and active electrophysiological properties were studied before and after application prostaglandin E(2) (PGE(2)). We observed marked differences between cutaneous and colonic sensory neurons with respect to baseline passive and active electrophysiological properties as well as both the magnitude and pattern of PGE(2)-induced changes in excitability, passive, and active properties. There were also significant differences between TL and LS neurons with respect to baseline and PGE(2)-induced changes in several passive and active electrophysiological properties. Our results suggest that differences between cutaneous and colonic neurons reflect differences in pattern and/or density of ionic currents present in the plasma membrane. More interestingly, the ionic currents underlying the PGE(2)-induced sensitization of cutaneous neurons appeared to differ from those underlying the sensitization of colonic neurons. The implication of this observation is that it may be possible, in fact necessary, to treat pain arising from specific body regions with unique therapeutic interventions.
与特定身体区域相关的疼痛综合征反映了支配这些区域的感觉神经元的独特特性和/或这些传入神经对组织损伤的独特反应。通过电流钳模式下的全细胞膜片钳记录，研究了从结肠或后爪无毛皮肤逆行标记的成年大鼠背根神经节（DRG）神经元。研究了两类结肠传入神经元：盆腔传入神经（起源于L(6)、S(1)和S(2) DRG = LS DRG）和腹下/腰结肠传入神经（起源于T(13)、L(1)和L(2) DRG = TL DRG）。在应用前列腺素E(2)（PGE(2)）之前和之后，研究了被动和主动电生理特性。我们观察到，皮肤和结肠感觉神经元在基线被动和主动电生理特性以及PGE(2)诱导的兴奋性、被动和主动特性变化的幅度和模式方面存在显著差异。TL和LS神经元在几种被动和主动电生理特性的基线和PGE(2)诱导变化方面也存在显著差异。我们的结果表明，皮肤和结肠神经元之间的差异反映了质膜中存在的离子电流模式和/或密度的差异。更有趣的是，PGE(2)诱导的皮肤神经元敏化所涉及的离子电流似乎与结肠神经元敏化所涉及的离子电流不同。这一观察结果的意义在于，实际上可能有必要用独特的治疗干预措施来治疗源自特定身体区域的疼痛。
