Wang Shuying, Albers Kathryn M
Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.
Ann N Y Acad Sci. 2009 Jul;1170:745-9. doi: 10.1111/j.1749-6632.2009.04011.x.
A study of the peripheral sensory system of young and aged Blk6 mice obtained from the National Institutes on Aging mouse colony is described. Behavioral assays showed male and female aged mice had decreased sensitivity to thermal stimuli. The receptor for the growth factor artemin (Artn), GFRalpha3, and the ion channel TRPV1, which is expressed by 95-99% of GFRalpha3-positive primary sensory neurons, was also decreased. Calcium imaging of isolated dorsal root ganglia neurons grown with nerve growth factor was used to test the in vitro effects of Artn on TRPV1 activation by capsaicin in young and old neurons. Artn potentiated initial TRPV1 responses to capsaicin in young and old neurons, but the percent of capsaicin responders following repeated exposure to capsaicin increased only in young neurons. The lack of change in aged neurons suggests that differences in TRPV1 responses occur with aging in the somatosensory system.
本文描述了一项对从美国国立衰老研究所小鼠种群获取的年轻和老年C57BL/6小鼠外周感觉系统的研究。行为学分析表明，老年雄性和雌性小鼠对热刺激的敏感性降低。生长因子Artemin（Artn）的受体GFRα3以及离子通道TRPV1（95%-99%的GFRα3阳性初级感觉神经元表达该通道）也减少。使用在神经生长因子存在下培养的离体背根神经节神经元进行钙成像，以测试Artn对辣椒素在年轻和老年神经元中激活TRPV1的体外作用。Artn增强了年轻和老年神经元对辣椒素的初始TRPV1反应，但在反复暴露于辣椒素后，辣椒素反应者的百分比仅在年轻神经元中增加。老年神经元中缺乏变化表明，体感系统中TRPV1反应的差异随衰老而出现。
