Quantitative analyses of total neuron numbers at three different neuronal levels in relation to olfactory function

Research Project

Project/Area Number	15K06737
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Nerve anatomy/Neuropathology
Research Institution	Shinshu University
Principal Investigator	MORIIZUMI Tetsuji 信州大学, 医学部, 特任教授 (70157874)
Co-Investigator(Kenkyū-buntansha)	福島菜奈恵信州大学, 学術研究院医学系, 准教授 (90334888)
Research Collaborator	YOKOUCHI Kumiko KUROIWA Masafumi
Project Period (FY)	2015-04-01 – 2018-03-31
Project Status	Completed (Fiscal Year 2017)
Budget Amount *help	¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000) Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000) Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000) Fiscal Year 2015: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Keywords	嗅上皮 / 嗅球 / 外側嗅索 / 嗅皮質 / 嗅覚 / 嗅覚受容器ニューロン / 嗅覚神経系 / 機能回復 / 再生軸索線維 / 定量解析 / 受容器ニューロン
Outline of Final Research Achievements	Cerebral cortical ablations in neonatal rats revealed that the anterior olfactory nucleus was not related to the olfactory discriminative ability and that the size of the remaining cortical regions of the piriform cortex and olfactory tubercle was important for the ability. Combined lesions of sectioning of the lateral olfactory tract and injections of a neurotoxin in adult rats showed similar results to the experiments in neonates and further uncovered that the minimal cortical size for the olfactory discriminative ability was approximately 20% of the normal cortical size. Transection of the lateral olfactory tract in neonatal rats revealed that functional revovery occurred as early as 10 days after tract transection and that areas and densities of regenerated nerve components essential for functional recovery were approximately 40% and 60% of the normal values in the olfactory cortices at the level of the olfactory tubercle.