How do somatosensory deficits after stroke relate to the recovery of fine finger movements

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K19898
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 59010:Rehabilitation science-related
• Research Institution: National Center of Neurology and Psychiatry
• Principal Investigator: Kubota Shinji 国立研究開発法人国立精神・神経医療研究センター, 神経研究所 モデル動物開発研究部, 室長 (40835419)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 筋感覚 / 手指運動機能 / 一次体性感覚野 / リハビリテーション / 脳損傷

Outline of Final Research Achievements

We have recorded neural activities in Brodmann area 3a and the cuneate nucleus (CN) from macaque monkeys performing a motor task. The neuronal responses of the cortex and the CN evoked by electrical stimulation of the deep radial nerve were clearly suppressed during active movement, regardless of movement direction. These results suggest that the feedback signals from movements are not uniformly transmitted to higher brain as the information of motor outcome, but that the incoming sensory signals may be filtered out at the CN. We observed that the monkey with damage to area 3a did not show any impairment in grasping, but had difficulty in performing fine motor skills such as pinching. The present study revealed that proprioceptive input is important for the execution of manual dexterity. The disability of fine finger movement in the patients with stroke could be related not only to problems in motor output but also to dysfunction in processing of feedback signals of movements.

Free Research Field

脳科学

Academic Significance and Societal Importance of the Research Achievements

本研究により、随意運動中の筋感覚情報処理の神経メカニズムの一端が明らかとなり、筋感覚が手指の巧緻運動の遂行に重要であることが示された。脳損傷後の巧緻運動機能障害は、運動出力の問題だけでなく、筋感覚情報処理の機能不全が関連していることが示唆された。脳卒中後のリハビリテーションにおいて運動機能の改善を図るためには、運動出力とともに感覚機能の改善に対するアプローチの重要性が示された。