Tactile stimulation elicits 50-kHz ultrasonic vocalizations in rats

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K16439
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Rehabilitation science/Welfare engineering
• Research Institution: International University of Health and Welfare
• Principal Investigator: Shimoju Rie 国際医療福祉大学, 基礎医学研究センター, 講師 (10433624)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 触刺激 / 超音波発声 / 情動 / 動機づけ / 側坐核 / ドーパミン / セロトニン / オピオイド

Outline of Final Research Achievements

The effects and neural mechanisms of ｍanual therapy using various tactile stimulation have yet to be clarified. We have previously shown that tactile stimulation can change the neural transmission in the nucleus accumbens, playing pivotal role in positive emotion. This study investigated the neural mechanisms involving generation of emotional change to tactile stimulation. Rats emit 50-kHz ultrasonic vocalizations (50-kHz USVs) in positive emotional state. The recordings of 50-kHz ultrasonic vocalizations emitted by rat were used to evaluate the call rate, indicating positive emotion. Rats emitted abundant 50-kHz USVs to tactile stimulation. Accumbal dopamine release were increased by tactile stimulation via 5-HT and opioid receptor in the nucleus accumbens. Emission of 50-kHz USVs to tactile stimulation were induced by accumbal dopamine release. These findings suggest that tactile stimulation may induce positive emotions through the activation of nucleus accumbens.

Free Research Field

神経生理学

Academic Significance and Societal Importance of the Research Achievements

本研究より、触刺激がモチベーションと関わる脳部位の神経伝達機能を変えることが明らかになった。さらに、触刺激によってラットが快情動状態となることが明らかとなり、触刺激が実際に快情動中枢の神経伝達機能を変えて、快情動を発現させる可能性が示された。本研究は、触刺激が対象者のリハビリへの動機付け、意欲向上に貢献する可能性を示すものであり、リハビリにおける触刺激の効果の科学的根拠の一つを示すものである。