Encoding mechanism of spatial information in the primate entorhinal-hippocampal system.

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K01991
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Brain biometrics
• Research Institution: University of Toyama
• Principal Investigator: Tamura Ryoi 富山大学, 学術研究部医学系, 教授 (60227296)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 内嗅皮質 / 霊長類 / 空間情報処理 / ニューロン活動 / 海馬 / 記憶 / 周期性徐波 / ニホンザル

Outline of Final Research Achievements

To clarify neural mechanism of information encoding in the primate hippocampo-entorhinal system, neuronal activity was recorded from the entorhinal cortex and its related brain areas in monkeys while the animal performed shuttling behavior on a linear track. Of the 348 neurons recorded in the entorhinal cortex and related areas, 15 showed spatially tuned activity, but none of these neurons exhibited clear gridness. Twenty one neurons showed rhythmic firing in the slow wave band, all of which were within the delta band (< 4 Hz); none of these neurons exhibited significant slow rhythmic firing in the theta band (5-10 Hz). These results indicate that the primate entorhinal cortex and related areas do encode spatial information in a different manner than the rodent entorhinal system where clear gridness and slow wave activity in the theta band appear in the activity of neurons in this system.

Free Research Field

神経科学

Academic Significance and Societal Importance of the Research Achievements

げっ歯類を用いた多くの研究より，海馬-内嗅皮質系には場所細胞やグリッド細胞が存在し，その細胞集団がシータ波帯域の周期性活動を行なうことが，空間認知に重要な役割を果たしている考えられてきた．本研究の学術的意義は，霊長類の内嗅皮質系でも空間情報処理は行なわれているが、グリッド性やシータ波帯域の周期性活動などげっ歯類の研究で得られてきた知見がヒトを含め、霊長類には見られないことを明らかにした点である。また、本研究の社会的意義は，当該学問分野の研究者に重要な示唆を与えるばかりでなく，認知科学，精神医学，人工知能，計算論的神経科学等の学問領域に対する波及効果もあることである．