Insausti A M, Megías M, Crespo D, Cruz-Orive L M, Dierssen M, Vallina I F, Insausti R, Flórez J
Department of Physiology and Pharmacology, Faculty of Medicine, University of Cantabria, Santander, Spain.
Neurosci Lett. 1998 Sep 11;253(3):175-8. doi: 10.1016/s0304-3940(98)00641-7.
Ts65Dn mouse displays a partial triplication of chromosome 16 and is adopted as a model for Down syndrome (DS). It is known that Ts65Dn mice present memory deficiencies. In order to gain insight into the cause of these deficiencies, we studied the possibility of changes in volumes and neuronal numbers in different regions of the hippocampus (dentate gyrus, CA3, CA2 and CA1) in trisomic mice as compared to control littermates using stereological methods. The mean hippocampal volumes of Ts65Dn mice did not show significant differences as compared to controls, except in CA2 where there was a barely significant decrease. However, mean neuron number was significantly lower in Ts65Dn mice than in controls in dentate gyrus (43.7 x 10(4), CV 21%, n = 5, vs. 30.4 x 10(4), CV 18.1%, n = 4) and higher in CA3 (23.1 x 10(4), CV 18.9% vs. 33.3 x 10(4), CV 14.9%). These quantitative changes may account for the memory deficiencies observed in Ts65Dn mice.
Ts65Dn小鼠表现出16号染色体的部分三体重复，被用作唐氏综合征（DS）的模型。已知Ts65Dn小鼠存在记忆缺陷。为了深入了解这些缺陷的原因，我们使用体视学方法研究了与对照同窝小鼠相比，三体小鼠海马体不同区域（齿状回、CA3、CA2和CA1）体积和神经元数量变化的可能性。与对照组相比，Ts65Dn小鼠的海马体平均体积没有显著差异，但CA2区有轻微的显著减小。然而，Ts65Dn小鼠齿状回的平均神经元数量显著低于对照组（43.7×10⁴，CV 21%，n = 5，对照组为30.4×10⁴，CV 18.1%，n = 4），而CA3区的平均神经元数量则高于对照组（23.1×10⁴，CV 18.9%，对照组为33.3×10⁴，CV 14.9%）。这些数量变化可能解释了在Ts65Dn小鼠中观察到的记忆缺陷。
