Basic research on the ultrastructural framework of the route for diffuse modulatory transmission in CNS

2014 Fiscal Year Final Research Report

• Project/Area Number: 24650181
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Nerve anatomy/Neuropathology
• Research Institution: Iwate Medical University
• Principal Investigator: TOHYAMA KOUJIRO 岩手医科大学, 医学部, 研究員 (10129033)
• Research Collaborator: ISHIDA Kinji 岩手医科大学, 医歯薬総合研究所, 技師長 ; HANASAKA Tomohito 岩手医科大学, 医歯薬総合研究所 ; MATSUURA Eri 岩手医科大学, 医歯薬総合研究所 ; OGASAWARA Katsutosi 岩手医科大学, 医歯薬総合研究所 ; NOZAKI Takayuki 岩手医科大学, 医歯薬総合研究所 ; ASADA Chikako 岩手医科大学, 医歯薬総合研究所 ; RICHARDSON William D University College London, Professor ; ATTWELL David University College London, Professor ; ANDERSON Patrick N University College London, Professor ; LIEBERMAN Alexander R University College London, Emeritus Professor
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 細胞間隙 / 反射電子像 / 電子線トモグラフィー / 三次元再構築 / シナプス間隙 / Ranvier絞輪 / グリア細胞 / 拡散的神経情報伝達

Outline of Final Research Achievements

Elucidation of the diffuse modulation system (DMS) is important to solve the role of neurons in the brainstem nuclei. To understand the 3D-ultrastructure (3DU) of the extra-cellular space (ECS), which support DMS transmission, we employed three high-technologies for electron microscopy, (i) rapid-freeze/substitution at ultra-low temperature (-269C) by liquid helium method (He-RF), (ii) double-axis electron beam tomography (DT), and (ii) back-scattered electron beam image analysis (BSE).
We obtained following new findings: (1) ECS occupied about 3.7% of whole tissue in volume; (2) He-RF and DT demonstrateddetails of 3DU in the synaptic cleft ; (3) BSE made clear 3DU of the node: glial processes enwrapped only 25% area of node axon, and 75% open to ECS; (4) tear-drop like protrusions from the node with denatured organelle were found and exhibited phagocytic appearance by glia, suggesting the possibility of a new concept that axon-derived debris are processed by glia.

Free Research Field

神経微細解剖学