장소: 온라인 세미나(GotoMeeting)로 진행 (https://global.gotomeeting.com/install/160555093)
강사: 박혜윤(서울대 물리천문학부 교수)
제목: Watching Single Endogenous mRNA in Neurons in vivo
내용: In this talk, I will present how we could begin to understand single molecule biophysics of gene expression during brain activities. The dynamics of mRNA – the synthesis, transport, and degradation – plays significant roles in a variety of neuronal processes. Abnormal mRNA processing and transport are implicated in neurological disorders such as autism and Alzheimer’s disease. However, understanding the mechanistic roles of RNA dynamics has been hampered by the lack of techniques to observe the endogenous molecules in the native tissue environment. Here I will describe a novel systems approach, combining single-particle tracking, genetic engineering, and intravital microscopy. Using a knock-in mouse model in which the endogenous Arc mRNA is labeled with GFP, we found that calcium activity was necessary but not sufficient for triggering Arc transcription and that blocking neuronal activity did not affect the dendritic transport of newly synthesized Arc mRNAs. Two-photon imaging of the live mouse brain revealed the immediate-early induction of Arc transcription in subpopulation of neurons in the CA1 region of the hippocampus after contextual fear conditioning and fear memory retrieval. The technology as demonstrated in our work, including the transgenic strategy and high-resolution microscopy of living tissue, will shed light on the dynamic regulation of gene expression during learning and memory processes in vivo.