The influence of parental support on child pain experiences is well recognised. Accordingly, animal studies have revealed both short- and long-term effects of early life stress on nociceptive responding and neural substrates such as endocannabinoids. The endocannabinoid system plays an important role in mediating and modulating stress, social interaction, and nociception. This study examined the effects of maternal support or acute isolation on nociceptive responding of female rats to a range of stimuli during the juvenile pre-adolescent period and accompanying changes in the endocannabinoid system. The data revealed that juvenile female Sprague Dawley rats (PND21−24) isolated from the dam for 1 h prior to nociceptive testing exhibited increased latency to withdraw in the hot plate test and increased mechanical withdrawal threshold in the Von Frey test, compared to rats tested in the presence of the dam. Furthermore, isolated rats exhibited reduced latency to respond in the acetone drop test and enhanced nociceptive responding in the formalin test when compared to dam-paired counterparts. Anandamide, but not 2-AG, levels were reduced in the prefrontal cortex of dam-paired, but not isolated, juvenile rats following nociceptive testing. There was no change in the expression of CB₁, FAAH or MAGL; however, CB₂ receptor expression was reduced in both dam-paired and isolated rats following nociceptive testing. Taken together the data demonstrate that brief social isolation or the presence of the dam modulates nociceptive responding of juvenile rat pups in a modality specific manner, and suggest a possible role for the endocannabinoid system in the prefrontal cortex in sociobehavioural pain responses during early life.

父母支持对儿童疼痛体验的影响已得到广泛认可。因此，动物研究揭示了早期生活压力对伤害性反应和神经基质（如内源性大麻素）的短期和长期影响。内源性大麻素系统在调解和调节压力、社交互动和伤害感受方面发挥着重要作用。这项研究检查了母体支持或急性隔离对雌性大鼠在青春期前青春期和伴随的内源性大麻素系统变化对一系列刺激的伤害性反应的影响。数据显示，与受试大鼠相比，在伤害性测试前 1 小时从大坝中分离出的幼年雌性 Sprague Dawley 大鼠 (PND21-24) 在热板试验中表现出增加的退缩潜伏期和在 Von Frey 试验中增加的机械退缩阈值在大坝面前。此外，与大坝配对的对应物相比，孤立的大鼠在丙酮滴落试验中表现出反应的潜伏期减少，并在福尔马林试验中表现出增强的伤害性反应。在伤害性测试后，大坝配对但不是孤立的幼年大鼠的前额叶皮层中 Anandamide 的水平降低，但 2-AG 没有降低。CB的表达没有变化 与大坝配对的对应物相比，孤立的大鼠在丙酮滴落试验中表现出反应的潜伏期减少，并在福尔马林试验中表现出增强的伤害性反应。在伤害性测试后，大坝配对但不是孤立的幼年大鼠的前额叶皮层中 Anandamide 的水平降低，但 2-AG 没有降低。CB的表达没有变化 与大坝配对的对应物相比，孤立的大鼠在丙酮滴落试验中表现出反应的潜伏期减少，并在福尔马林试验中表现出增强的伤害性反应。在伤害性测试后，大坝配对但不是孤立的幼年大鼠的前额叶皮层中 Anandamide 的水平降低，但 2-AG 没有降低。CB的表达没有变化₁、FAAH或MAGL；然而，在伤害性测试后，母鼠配对和离体大鼠的CB ₂受体表达均降低。综合数据表明，短暂的社会隔离或大坝的存在以特定方式调节幼鼠的伤害性反应，并表明内源性大麻素系统在生命早期的社会行为疼痛反应中可能在前额叶皮层中发挥作用。