Thermal hyperalgesia and dynamic weight bearing share similar recovery dynamics in a sciatic nerve entrapment injury model.
Thermal hyperalgesia and dynamic weight bearing share similar recovery dynamics in a sciatic nerve entrapment injury model.
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DOI：
10.1016/j.ynpai.2021.100079
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发表时间：
2021-08
期刊：
影响因子：
--
通讯作者：
Bhattacharjee A
中科院分区：
文献类型：
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作者：
Sheehan GD;Martin MK;Young VA;Powell R;Bhattacharjee A
神经病理性疼痛的坐骨神经袖套模型显示疼痛恢复。热痛敏和动态负重表现出相似的疼痛恢复特征，而机械性超敏持续存在。动态负重是对神经卡压期间持续疼痛的非反射性疼痛评估。坐骨神经慢性压迫性损伤(CCI)是神经病理性疼痛广泛应用的神经卡压动物模型。CCI后观察到的两种常见的疼痛行为是热痛觉过敏和机械性超敏，分别通过Hargreaves和von Frey测试进行测量。虽然热痛觉过敏往往会在30天后恢复，但机械性痛觉过敏可以在此后持续数月。因此，机械性超感痛症被广泛用作衡量“慢性疼痛”的指标，其重点是脊髓内发生的回路变化。在这里，使用小鼠的坐骨神经袖套变种CCI，我们认为，与这些伤害性超敏反应的诱发指标相比，动态负重为神经损伤期间的持续性疼痛提供了一种更具临床相关性的行为指标。我们发现，坐骨神经袖带对受伤的后肢与未受伤的后肢的负重比的影响更接近于热痛觉过敏，并有30天恢复的趋势。我们还发现，对侧爪子的负重百分比增加了，这在之前的测试行为中是看不到的。这些结果表明，动态负重是一种可靠的非诱发神经病理性疼痛的测量方法，并提示热痛觉过敏而不是机械性超敏为神经卡压引起的持续性疼痛提供了一种替代方法。
The sciatic nerve cuff model of neuropathic pain exhibits pain recovery. Thermal hyperalgesia and dynamic weight bearing display similar pain recovery profiles, whereas mechanical allodynia persists. Dynamic weight bearing is a non-reflexive, pain assessment of ongoing pain during nerve entrapment. Chronic constriction injuries (CCI) of the sciatic nerve are widely used nerve entrapment animal models of neuropathic pain. Two common pain behaviors observed following CCI are thermal hyperalgesia and mechanical allodynia, measured by the Hargreaves and von Frey tests, respectively. While thermal hyperalgesia tends to recover by 30 days, mechanical allodynia can persist for many more months thereafter. Consequently, mechanical allodynia has been used extensively as a measure of ‘chronic pain’ focusing on the circuitry changes that occur within the spinal cord. Here, using the sciatic nerve cuff variant of CCI in mice, we propose that in contrast to these evoked measures of nociceptive hypersensitivity, dynamic weight bearing provides a more clinically relevant behavioral measure for ongoing pain during nerve injury. We found that the effect of sciatic nerve cuff on the ratio of weight bearing by the injured relative to uninjured hindlimbs more closely resembled that of thermal hyperalgesia, following a trend toward recovery by 30 days. We also found an increase in the percent of body weight bearing by the contralateral paw that is not seen in the previously tested behaviors. These results demonstrate that dynamic weight bearing is a reliable measure of non-evoked neuropathic pain and suggest that thermal hyperalgesia, rather than mechanical allodynia, provides a proxy measure for nerve entrapment-induced ongoing pain.