雌雄小鼠对伤害性刺激敏感度不同和缰外侧核反应有关
Sex difference in aversive stimulation is associated with the activity of lateral habenula in mice

摘要：目的 探讨雌雄小鼠对伤害性刺激的反应与缰外侧核CaMK-2β表达的关系。方法 C57B/L雄性和雌性成年小鼠，给予等量的非条件刺激(足底电刺激)联合条件刺激(光刺激和声音刺激)，24h后观察不同性别小鼠对刺激场景的反应；48h后给予条件性消退训练，观察雌雄小鼠的反应。免疫组织化学结合半定量技术检测缰外侧核CaMK-2β阳性细胞的数量，Western blot技术检测缰外侧核CaMK-2β蛋白表达。结果 与雄性小鼠相比，雌性小鼠对伤害性场景更加敏感，对消退训练的耐受增加。伤害性刺激后48h，雌性小鼠缰外侧核CaMK-2β阳性细胞数量高于对照组(P<0.05)，缰外侧核CaMK-2β的表达高于对照组(P=0.027)。结论 雌雄小鼠对伤害性刺激反应和伤害性信息巩固时程不同，这一差别可能和缰外侧核CaMK-2β表达水平有关。
ABSTRACT: Objective? ?To explore the difference in response to aversive stimulation and the expression of CaMK-2β in the lateral habenula between male and female mice. Methods?? Male and female mice were given the non-condition stimulation with electric shock associated with the condition-stimulation with the light and tone context. After 24 hours, the mice were placed into the stimulation context and their responses were recorded and analyzed. At 48 hours after non-condition stimulation, the effects on extinction were observed in the male and female mice. Immunohistochemical method was used to detect the number of CaMK-2β positive cells in the lateral habenula nucleus. The expression of CaMK-2β protein in the lateral habenula was detected by Western blot. Results ？？Female mice were more sensitive to context cue compared with the male mice. Similarly, the female mice were more tolerant to extinction than their male counterparts. Consistently, at 48 hours after aversive stimulation, the CaMK-2β-positive cells in lateral habenula of female mice outnumbered those of the male mice. Additionally, the expression of CaMK-2β in habenula protein was higher in the female mice than in the male mice after aversive stimulation. Conclusion?? Male and female mice showed different responses to the same stress stimulation, which determined the consolidation to stress information. The sex difference in aversive stimulation may contribute to the expression of CaMK-2β in the lateral habenula.