Bentivoglio A R, Altavista M C, Granata R, Albanese A
Istituto di Neurologia, Università Cattolica del Sacro Cuore, Roma, Italy.
Brain Res. 1994 Feb 21;637(1-2):181-9. doi: 10.1016/0006-8993(94)91231-9.
This study demonstrates that a deficiency of forebrain cholinergic neurons occurs in C57BL/6 (C57) mice, a strain characterized by poor learning capabilities. The brains of 21-day-old and 18-week-old C57 and DBA/2 (DBA) mice were studied by means of acetylcholinesterase (AChE) histochemistry and of choline acetyltransferase (ChAT) immunocytochemistry. Computer-assisted image analysis was performed on sections through the medial septum, the diagonal band of Broca, the basal nucleus of Meynert and the neostriatum. As compared to the DBA strain, C57 mice had a reduced number of forebrain cholinergic neurons. This feature was present at the age of 21 days and persisted to 18 weeks. Between-strain variations in the density of neurons were more obvious in ChAT-stained material than in AChE-stained sections. These data show that C57 mice can be regarded as a genetic mutant, whose phenotype is characterized by a reduced number of forebrain cholinergic neurons and by cognitive abnormalities. C57 mice represent a valuable model for studying the influence of genetic factors on central nervous system cholinergic mechanisms and the effects of genetically determined cholinergic deficiency on behavior and learning.
本研究表明，在C57BL/6（C57）小鼠中发生了前脑胆碱能神经元的缺乏，该品系的特征是学习能力较差。通过乙酰胆碱酯酶（AChE）组织化学和胆碱乙酰转移酶（ChAT）免疫细胞化学方法研究了21日龄和18周龄的C57和DBA/2（DBA）小鼠的大脑。对穿过内侧隔、布罗卡斜带、迈内特基底核和新纹状体的切片进行了计算机辅助图像分析。与DBA品系相比，C57小鼠的前脑胆碱能神经元数量减少。这一特征在21日龄时就已存在，并持续到18周。ChAT染色材料中神经元密度的品系间差异比AChE染色切片中更明显。这些数据表明，C57小鼠可被视为一种基因变异体，其表型的特征是前脑胆碱能神经元数量减少和认知异常。C57小鼠是研究遗传因素对中枢神经系统胆碱能机制的影响以及遗传决定的胆碱能缺乏对行为和学习的影响的有价值模型。
