The Study of Neuronal Morphology in TDP Transgenic Mice

• Main Authors: Yi-Ting Chen, 陳怡婷
• Other Authors: Che-Kun James Shen
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/tbxjn2

碩士 === 國立陽明大學 === 生命科學暨基因體科學研究所 === 97 === In the past, TAR DNA binding protein-43 (TDP-43) is a well-known nuclear factor that carried out dual functions, both as a transcriptional repressor and an activator of exon skipping, implicated in alternative splicing. Until a couple of years ago, it was found that TDP-43 colocalized with other two RNA-binding proteins, fragile X mental retardation protein (FMRP) and Staufen 1, which are known to regulate neuronal activities, involving in the establishment of learning/memory capabilities. Interestingly, TDP-43-containing inclusions bodies aggregate in the cytosol in many neurodegenerative diseases, featuring TDP-43-positive ubiquitinated inclusions (UBIs), including frontotemporal lobar degeneration with ubiquitin-positive, tau- and α-synuclein-negative inclusions (FTLD-U) and amyotrophic lateral sclerosis (ALS). In our lab, we have established that CaMKII-TDP overexpression at specific regions (hippocampus and cortex) transgenic mice may involve in the impairment of learning/memory capabilities by behavior test (the Morris Water Maze test). Therefore, in order to distinguish the neuronal morphology, connection and distribution at the cellular level between TDP transgene and wild type controls, we applied the technology of single-cell microinjection. In the study, we used two different dyes, Sulforhodamine101 and Biocytin, and find that there is no significant difference in total neurite length, neuritic main shaft number, neuritic branch number, and the average length of each basal neurite at the different time points. However, spine density was quantitatively measured for WT and TDP Tg of Biocytin-injected and GFP expression systems and observed that hippocampal neurons taken from TDP Tg mice grown in culture from D.I.V. 7 have fewer dendritic spines than WT controls. These findings suggest and highlight that these observations may have important implications for understanding of learning/memory decline associated with overexpression of TDP.