Department of Physiology, University of Florence, Florence, Italy.
Neuroscience. 2010 Apr 14;166(4):1129-39. doi: 10.1016/j.neuroscience.2010.01.040. Epub 2010 Jan 28.
The dystrophin defective mdx mouse, acknowledged model of Duchenne Muscular Dystrophy (DMD), bears outstanding alterations of the cortical architecture, that could be responsible for the cognitive impairment often accompanying this pathological condition. Using a retrograde tract tracing technique to label neurons in Golgi-like fashion, we investigated the fine anatomical organization of associative cortico-cortical projections in mdx mice. While the absolute number of associative pyramidal neurons was significantly higher in mdx than in control animals, the ratio between the number of supra- and infragranular cortico-cortical cells was substantially unmodified. Basal dendrites of layer 2/3 pyramidal neurons displayed longer terminal branches in mdx compared to controls. Finally, the density of dendritic spines was significantly lower in mdx animals. The anomalies of associative cortico-cortical projections provide potential groundwork on the neurobiological bases of cognitive involvement in DMD and value the role of cortical microcircuitry alterations as possible source of interference with peripheral motor impairment.
肌营养不良蛋白缺陷型 mdx 小鼠，公认的杜氏肌营养不良症（DMD）模型，其皮质结构有明显改变，这可能是该病理状况常伴随认知障碍的原因。我们使用逆行示踪技术以类高尔基方式标记神经元，研究了 mdx 小鼠的联合皮质-皮质投射的精细解剖组织。虽然 mdx 小鼠的联合皮质神经元数量明显高于对照组，但上和下颗粒层皮质细胞的数量比例基本不变。与对照组相比，mdx 小鼠的第 2/3 层锥体神经元的基底树突的末端分支更长。最后，mdx 动物的树突棘密度显著降低。联合皮质-皮质投射的异常为 DMD 认知障碍的神经生物学基础提供了潜在的基础，并证明了皮质微电路改变作为干扰外周运动障碍的可能来源的重要作用。
