Hu D, Hu R, Berde C B
Department of Anesthesia, Children's Hospital, Boston, Massachusetts, USA.
Anesthesiology. 1997 Apr;86(4):957-65. doi: 10.1097/00000542-199704000-00026.
Only limited data exist comparing differences in sensory function and responses to neural blockade in infant and adult rats. Therefore, the authors sought (1) to compare baseline thermal, proprioceptive, and postural responses in infant, adolescent, and adult rats; and (2) to compare the effects of sciatic nerve blockade on thermal, proprioceptive, and postural responses in infant, adolescent, and adult rats.
Infant, adolescent, and adult rats were evaluated for proprioceptive, thermal, and mechanical nociceptive and motor function before and after sciatic blockade using a detailed neurologic examination.
Mechanical and thermal nociception were present in all rats, starting from age 1 day. The withdrawal reflex latency to pinch was rapid at all ages, whereas that reaction to thermal stimulus depended on both age and temperature. In contrast, the tactile placing response and hopping response were absent at birth and developed completely during the first 10 days of life. The extensor postural thrust was absent in the first 2 weeks of life and developed variably during the first 50 days of life. Sciatic blockade duration is shorter in infant rats than in adult rats receiving the same dose per kilogram. A brief halothane general anesthetic at the time of sciatic injection in infant or adult rats does not alter the duration of blockade.
Infant rats show increased sensitivity to noxious thermal stimuli and similar response to deep mechanical stimuli compared with adult rats. Their proprioceptive and motor responses develop during the first 2 weeks of life. When doses are scaled by body weight, block duration is shorter in infant than in adult rats.
关于比较幼鼠和成年大鼠感觉功能差异以及对神经阻滞反应的数据有限。因此，作者旨在：（1）比较幼鼠、青春期大鼠和成年大鼠的基线热觉、本体感觉和姿势反应；（2）比较坐骨神经阻滞对幼鼠、青春期大鼠和成年大鼠热觉、本体感觉和姿势反应的影响。
使用详细的神经学检查评估幼鼠、青春期大鼠和成年大鼠在坐骨神经阻滞后的本体感觉、热觉、机械性伤害感受和运动功能。
所有大鼠从1日龄开始就存在机械性和热觉伤害感受。所有年龄段对捏的退缩反射潜伏期都很快，而对热刺激的反应则取决于年龄和温度。相比之下，触觉放置反应和跳跃反应在出生时不存在，并在出生后的前10天内完全发育。伸肌姿势推力在出生后的前2周不存在，并在出生后的前50天内不同程度地发育。幼鼠的坐骨神经阻滞持续时间比每公斤接受相同剂量的成年大鼠短。在幼鼠或成年大鼠坐骨神经注射时给予短暂的氟烷全身麻醉不会改变阻滞持续时间。
与成年大鼠相比，幼鼠对有害热刺激的敏感性增加，对深部机械刺激的反应相似。它们的本体感觉和运动反应在出生后的前2周内发育。当按体重计算剂量时，幼鼠的阻滞持续时间比成年大鼠短。
