Establishment of a new technique for time lapse imaging of activity pattern of engram cells from pre- to post-learning phase

2015 Fiscal Year Final Research Report

• Project/Area Number: 26640008
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Neurophysiology / General neuroscience
• Research Institution: University of Toyama
• Principal Investigator: OHKAWA Noriaki 富山大学, 大学院医学薬学研究部(医学), 講師 (80416651)
• Co-Investigator(Renkei-kenkyūsha): INOKUCHI Kaoru 富山大学, 大学院医学薬学研究部(医学), 教授 (20318827)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: Ca2+イメージング / 学習 / 記憶 / 記憶痕跡細胞 / 神経活動 / 遺伝子発現 / レンチウイルス

Outline of Final Research Achievements

To identify rules for expression of engram, we proposed to establish a new technique to observe activity pattern of engram cells from pre- to post-learning phase.
We installed a GRIN lens on hippocampal CA1, and a miniature microscope detected fluorescence signals in the CA1 through the GRIN lens. Then we applied the microscopy on transgenic mice in which hippocampal neurons express G-CaMP and engram cells express a fluorescence protein, KikGR. The G-CaMP is a calcium indicator and shows fluorescence when neural activity induces calcium influx into the CA1 neurons. We have succeeded to observe both of engram cells expressing the KikGR and activity-mediated G-CaMP fluorescence of ~400 neurons from freely moving mice with the miniature microscope.
The new technique will allow to investigate comparisons of activity pattern between engram cells and others during memory processing.

Free Research Field

分子細胞神経科学