Neuropsycopharmacological investigation on animal learning based on contiguity or contingency between events

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K21364
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Experimental psychology; Neurophysiology / General neuroscience
• Research Institution: Waseda University (2017-2018); Keio University (2016)
• Principal Investigator: Kosaki Yutaka 早稲田大学, 文学学術院, 准教授 (80738469)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 連合学習 / 薬物依存 / 随伴性学習 / 習慣形成

Outline of Final Research Achievements

Animals, including humans, learn about relationships between multiple events in the environment or between their own behaviour and external events, through at least two distinct learning processes; contiguity-based learning and contingency-based learning processes. The two processes are thought to rely on dissociable neural circuits. The current project sought to reveal fundamental variables that brings about the formation of each type of learning, using mice as subjects. Chronic pre-exposure to methamphetamine disrupted animals' sensitivity to the instrumental contingency between behaviour and its outcome. In a modified version of conditioned place preference task, a form of Pavlovian conditioning task, pairing a compound CS with methamphetamine US did not result in overshadowing, thereby showing a disruption of contingency-based learning. Together the results suggest hat the drug of abuse, such as methamphetamine, promote learning based simply on the contiguity between events.

Free Research Field

学習理論・行動神経科学

Academic Significance and Societal Importance of the Research Achievements

複数事象間の関連性を学習する連合学習の根本原理を解明することは、ヒトを含む動物の適応的な認知・行動を解明する上で必須である。本研究では接近性に基づく学習と、情報としてもう一段階複雑な計算が要求される随伴性知覚に基づく学習の形成要因について実験的検討を行い、濫用薬物が後者を阻害することを明らかにした。随伴生学習はうつ病や統合失調症、薬物依存、自閉スペクトラム症など多くの精神疾患・発達障害において異常が見られ、その解明は連合学習の根本原理の解明のみならず、その異常の機序を理解する上でも重要である。本研究ではマウスを用いた基礎的な行動薬理実験を通じて、このメカニズムの一旦を明らかにすることができた。