Hamm R J, Knisely J S
Department of Psychology, Virginia Commonwealth University, Richmond 23284-2018.
Brain Res Bull. 1988 Dec;21(6):933-46. doi: 10.1016/0361-9230(88)90031-7.
Research has documented the existence of multiple, endogenous systems that modulate nociception. Based on the effects of opioid antagonists and endocrine lesions, endogenous analgesia systems have been organized into four classes: neural-opioid, neural-nonopioid; hormonal-opioid; hormonal-nonopioid. Developmental research on the ontogeny of endogenous analgesic function has revealed differential rates of maturation. Front-paw shock, a stimulus that activates a neural-opioid analgesic response, has been shown to be functionally mature by 28 days of age in the rat. Similarly, hind-paw shock, a stimulus that elicits a neural-nonopioid analgesic response, reaches maturity after two months of age. However, the hormonal-opioid analgesic system activated by cold-water immersion reaches adult levels by 10 days of age. Food deprivation produces a hormonal-opioid analgesic response in adult rats, and food deprivation/isolation of rat pups has been found to elicit an analgesic response in 6-day-old rats. From these data it seems that the rate of development of the different endogenous analgesic systems is related to the activation of neural or hormonal components. Whether the differential rates of development and the neural-hormonal distinction are related to the ecological validity of the activating stimulus remains to be determined.
研究已证明存在多种调节伤害感受的内源性系统。基于阿片类拮抗剂和内分泌损伤的作用，内源性镇痛系统已被分为四类：神经 - 阿片类、神经 - 非阿片类、激素 - 阿片类、激素 - 非阿片类。对内源性镇痛功能个体发育的研究揭示了不同的成熟速率。前爪电击是一种能激活神经 - 阿片类镇痛反应的刺激，在大鼠出生28天时已被证明在功能上成熟。同样，后爪电击是一种能引发神经 - 非阿片类镇痛反应的刺激，在出生两个月后达到成熟。然而，由冷水浸泡激活的激素 - 阿片类镇痛系统在出生10天时达到成年水平。食物剥夺在成年大鼠中产生激素 - 阿片类镇痛反应，并且已发现剥夺大鼠幼崽的食物/将其隔离会在6日龄大鼠中引发镇痛反应。从这些数据来看，不同内源性镇痛系统的发育速率似乎与神经或激素成分的激活有关。发育速率的差异以及神经 - 激素的区别是否与激活刺激的生态效度相关仍有待确定。
