Department of Orthodontics, University of Florida, 1600 SW Archer Road, PO Box 100444, Gainesville, FL 32610, USA.
J Gerontol A Biol Sci Med Sci. 2010 Apr;65(4):353-62. doi: 10.1093/gerona/glq024. Epub 2010 Feb 25.
Age-dependent changes in thermal sensitivity were evaluated with reflex- and operant-based assessment strategies in animals ranging in age from 8 to 32 months. The impact of inflammatory injury on thermal sensitivity was also determined in animals of different ages. The results showed that operant measures of escape behavior are needed to demonstrate significant changes in thermal sensitivity across the life span of female Long-Evans rats. Increased escape from both heat (44.5 degrees C) and cold (1.5 degrees C-15 degrees C) was observed for older animals, with a greater relative increase in sensitivity to cold. Physical performance deficits were demonstrated with aging but were not associated with changes in escape responding. Reflex responding to cold stimulation was impaired in older animals but was also influenced by physical disabilities. Reflex responding to heat was not affected by increasing age. Inflammation induced by formalin injections in the dorsal hindpaw increased thermal sensitivity significantly more in older animals than in their younger counterparts.
采用基于反射和操作性条件反射的评估策略，研究了年龄在 8 至 32 个月之间的动物的热敏感性的年龄依赖性变化。还在不同年龄的动物中确定了炎症损伤对热敏感性的影响。结果表明，需要操作性的逃避行为测量来证明雌性 Long-Evans 大鼠在整个生命周期内的热敏感性发生显著变化。与年轻动物相比，老年动物对热（44.5°C）和冷（1.5°C-15°C）的逃避反应增加，对冷的敏感性增加相对较大。随着年龄的增长，身体机能表现出缺陷，但与逃避反应的变化无关。对冷刺激的反射反应在老年动物中受损，但也受到身体残疾的影响。随着年龄的增长，对热的反射反应不受影响。与年轻动物相比，福尔马林注射引起的背后爪炎症明显增加了老年动物的热敏感性。
