Singer H S, Tiemeyer M, Hedreen J C, Gearhart J, Coyle J T
Brain Res. 1984 Aug;317(2):155-66. doi: 10.1016/0165-3806(84)90093-2.
Telencephalic and diencephalic/brainstem regions from embryonic trisomy-16 mice (Ts16) between gestational days 15-18 were analyzed for alterations of morphologic and neurochemical parameters and compared to phenotypically normal littermates. Mean trisomic wet weights from both regions were significantly diminished (greater than 20%) and total protein content was reduced. Ratios of the thickness of the ventricular (germinal) zone to the thickness of the whole cortex were increased, suggesting a delay in neuronal differentiation. Pre- and postsynaptic markers for GABAergic, cholinergic, catecholaminergic and serotonergic transmitter systems were compared. A significant impairment of the trisomic brain catecholaminergic and serotonergic system development was observed, based upon regional reductions in norepinephrine, dopamine and serotonin content. Choline acetyltransferase activity in the diencephalon/brainstem was reduced by 21-26% in contrast to normal levels within the cerebral hemispheres. Presynaptic GABAergic markers were not affected in the Ts16 embryos. It is concluded that although a genetic imbalance involving chromosome 16 in the mouse embryo produces a delay in neurogenesis, it has a more selective effect on the catecholaminergic, serotonergic and cholinergic systems than on GABAergic neurons.
对妊娠第15 - 18天的胚胎16三体小鼠（Ts16）的端脑和间脑/脑干区域进行分析，以观察形态学和神经化学参数的变化，并与表型正常的同窝小鼠进行比较。两个区域的三体平均湿重均显著降低（超过20%），总蛋白含量减少。脑室（生发）区厚度与整个皮质厚度的比值增加，提示神经元分化延迟。比较了γ-氨基丁酸能、胆碱能、儿茶酚胺能和5-羟色胺能递质系统的突触前和突触后标志物。基于去甲肾上腺素、多巴胺和5-羟色胺含量的区域减少，观察到三体脑儿茶酚胺能和5-羟色胺能系统发育存在显著损害。与大脑半球内的正常水平相比，间脑/脑干中的胆碱乙酰转移酶活性降低了21 - 26%。Ts16胚胎中的突触前γ-氨基丁酸能标志物未受影响。得出的结论是，尽管小鼠胚胎中涉及16号染色体的基因失衡会导致神经发生延迟，但它对儿茶酚胺能、5-羟色胺能和胆碱能系统的影响比对γ-氨基丁酸能神经元的影响更具选择性。
