Department of Morphology, Stomatology and Physiology, School of Dentistry of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
Angle Orthod. 2010 Jan;80(1):111-5. doi: 10.2319/100708-522.1.
To determine if the magnitude of the force used to induce incisor tooth movement promotes distinct activation in cells in the central amygdala (CEA) and lateral hypothalamus (LH) of rats. Also, the effect of morphine on Fos immunoreactivity (Fos-IR) was investigated in these nuclei.
Adult male rats were anesthetized and divided into six groups: only anesthetized (control), without orthodontic appliance (OA), OA but without force, OA activated with 30g or 70g, OA with 70g in animals pretreated with morphine (2 mg/kg, intraperitoneal). Three hours after the onset of the experiment the rats were reanesthetized and perfused with 4% paraformaldehyde. The brains were removed and fixed, and sections containing CEA and LH were processed for Fos protein immunohistochemistry.
The results show that in the control group, the intramuscular injection of a ketamine/ xylazine mixture did not induce Fos-IR cells in the CEA or in the LH. Again, the without force group showed a little Fos-IR. However, in the 70g group the Fos-IR was the biggest observed (P < .05, Tukey) in the CEA and LH compared with the other groups. In the 30g group, the Fos-IR did not differ from the control group, the without OA group, and the without force group. Furthermore, pretreatment with morphine in the 70g group reduced Fos-IR in these regions.
Tooth movement promotes Fos-IR in the CEA and LH according to the magnitude of the force applied.
确定用于诱导切牙牙齿移动的力的大小是否会促进大鼠中枢杏仁核 (CEA) 和外侧下丘脑 (LH) 细胞的明显激活。此外，还研究了吗啡对这些核中 Fos 免疫反应性 (Fos-IR) 的影响。
成年雄性大鼠麻醉后分为六组：仅麻醉（对照）、无正畸矫治器（OA）、无正畸矫治器但无作用力、OA 激活 30g 或 70g、OA 激活 70g 且动物预先用吗啡（2mg/kg，腹腔内）预处理。实验开始后 3 小时，大鼠再次麻醉并用 4%多聚甲醛灌注。取出大脑并固定，然后处理包含 CEA 和 LH 的切片进行 Fos 蛋白免疫组织化学。
结果表明，在对照组中，肌肉注射氯胺酮/二甲苯胺混合物不会在 CEA 或 LH 中诱导 Fos-IR 细胞。同样，无作用力组显示出很少的 Fos-IR。然而，在 70g 组中，与其他组相比，CEA 和 LH 中的 Fos-IR 最大（P<.05，Tukey）。在 30g 组中，Fos-IR 与对照组、无 OA 组和无作用力组没有差异。此外，70g 组中吗啡预处理减少了这些区域的 Fos-IR。
根据施加力的大小，牙齿移动会促进 CEA 和 LH 中的 Fos-IR。
