De Bartolo P, Florenzano F, Burello L, Gelfo F, Petrosini L
IRCCS Santa Lucia Foundation, Via Del Fosso di Fiorano 64, 00143, Rome, Italy,
Brain Struct Funct. 2015 Sep;220(5):2895-904. doi: 10.1007/s00429-014-0833-6. Epub 2014 Jul 15.
The environmental enrichment (EE) paradigm is widely used to study experience-dependent brain plasticity. In spite of a long history of research, the EE influence on neuronal morphology has not yet been described in relation to the different regions of the cerebellum. Thus, aim of the present study was to characterize the EE effects on density and size of dendritic spines of Purkinje cell proximal and distal compartments in cerebellar vermian and hemispherical regions. Male Wistar rats were housed in an enriched or standard environment for 3.5 months from the 21st post-natal day onwards. The morphological features of Purkinje cell spines were visualized on calbindin immunofluorescence-stained cerebellar vermian and hemispherical sections. Density, area, length and head diameter of spines were manually (ImageJ) or automatically (Imaris) quantified. Results demonstrated that the Purkinje cell spine density was higher in enriched rats than in controls on both proximal and distal dendrite compartments in the hemisphere, while it increased only on distal compartment in the vermis. As for spine size, a significant increase of area, length and head diameter was found in the distal dendrites in both vermis and hemisphere. Thus, the exposure to a complex environment enhances synapse formation and plasticity either in the vermis involved in balance and locomotion and in the hemisphere involved in complex motor adaptations and acquisition of new motor strategies. These data highlight the importance of cerebellar activity-dependent structural plasticity underling the EE-related high-level performances.
环境丰富化(EE)范式被广泛用于研究经验依赖的脑可塑性。尽管有很长的研究历史,但EE对神经元形态的影响尚未与小脑的不同区域相关联进行描述。因此,本研究的目的是表征EE对小脑蚓部和半球区域浦肯野细胞近端和远端区室树突棘密度和大小的影响。从出生后第21天起,将雄性Wistar大鼠饲养在丰富环境或标准环境中3.5个月。在钙结合蛋白免疫荧光染色的小脑蚓部和半球切片上观察浦肯野细胞棘的形态特征。手动(ImageJ)或自动(Imaris)对棘的密度、面积、长度和头部直径进行量化。结果表明,丰富环境饲养的大鼠半球近端和远端树突区室的浦肯野细胞棘密度均高于对照组,而蚓部仅远端区室的棘密度增加。至于棘的大小,在蚓部和半球的远端树突中均发现面积、长度和头部直径显著增加。因此,暴露于复杂环境可增强参与平衡和运动的蚓部以及参与复杂运动适应和新运动策略习得的半球中的突触形成和可塑性。这些数据突出了小脑活动依赖的结构可塑性在与EE相关的高水平表现中的重要性。