单侧磨牙缺失对老年学习记忆减退大鼠基底前脑胆碱能系统的影响

Influence of unilateral molarless on basal forebrain cholinergic system in learning and memory deficit aged rats

目的:探讨单侧缺牙对不同学习记忆能力老年大鼠基底前脑胆碱能系统的影响。方法:用Morris水迷宫筛选出老年记忆减退鼠和老年记忆正常鼠,拔除单侧磨牙后2个月,用免疫组化和组织化学染色观察对其斜角带核垂直支胆碱能神经元和海马CA1区、前额皮质胆碱能纤维密度的影响。结果:斜角带核垂直支ChAT阳性细胞数和海马CA1区、前额皮质AChE阳性纤维密度在老年记忆减退鼠中,拔牙组较对照组(未拔牙)明显下降;海马CA1区AChE阳性纤维密度在老年记忆正常鼠中,拔牙组较对照组明显下降。结论:单侧磨牙缺失可加速老年学习记忆减退鼠基底前脑胆碱能系统的损害。

Objective： To explore the effect of unilateral molarless on spatial memory and basal forebrain cholinergic system in aged rats with different learning and memory ability. Methods： Learning and memory deficit rats （DR） and normal rats （NR） were selected from aged rats by Morris water maze. Then, the rats were randomly divided into unilateral molars extraction groups and control groups. Cholineacetyltransferase （CHAT） positive cells in the nucleus of the vertical limb of the diagonal band （VDB） and acetylcholinersterase （ACHE） positive fibers in prefrontal cortex （PFC） and in hippocampal CA1 region of all experimental animals were examined using immunohistochemical and histochemical techniques after removal of their unilateral molars. Results： The unilateral molarless DR showed a reduced number of ChAT-positive cells in VDB and decreased density of AChE-positive fibers in PFC and hippocampal CA1 region compared to those in the intact molars DR in the control group （P（0. 05）. The unilateral molarless NR showed decreased density of AChE-positive fibers in hippocampal CA1 region compared to that in the intact molars NR in the contorl group （P〈0.01）. Conclusion： The unilateral molarless enhance the impairment of cholinergic system in the basal forebrain system in DR.