Development of deep brain imaging technology in behaving animals: stability and instability of neuronal circuit under physiological and pathophysiological conditions

2014 Fiscal Year Final Research Report

• Project Area: Generation of synapse-neurocircuit pathology
• Project/Area Number: 22110006
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: The Institute of Physical and Chemical Research
• Principal Investigator: HAYASHI Yasunori 独立行政法人理化学研究所, 脳科学総合研究センター, チームリーダー (90466037)
• Co-Investigator(Renkei-kenkyūsha): SATO Masaaki 独立行政法人理化学研究所, 脳科学総合研究センター, 客員研究員 (90518325) ; UEDA Yoshibumi 独立行政法人理化学研究所, 小林脂質生物学研究室, 協力研究員 (60391877)
• Project Period (FY): 2010-04-01 – 2015-03-31
• Keywords: 海馬 / 記憶 / 神経細胞集成体 / シナプス可塑性

Outline of Final Research Achievements

Hippocampus is involved in the encoding an episodic experience into a physical trace in brain. However, how an episode is represented at cellular resolution, how long it lasts, and whether the same representation is reinstated upon recall are still not fully elucidated due to the lack of method to longitudinally observe representation. We performed two-photon microscopic Ca2+-imaging of ~1000 CA1 pyramidal neurons from mouse dorsal hippocampus during a familiar episodic event under virtual reality over two weeks. The hippocampal representation consists of a group of neurons firing sequentially during the event; ~2% of the cells fire at specific time point consistently while ~20% join the representation on each day and turn over in a few days. A change in the episode sequence largely eliminates both components, even the animal is behaviorally recalling the episode indicating the retrieval of a familiar episodic sequence can take place without a reinstatement of the same representation.

Free Research Field

総合領域