Roles of dopamine D5 receptors in the medial prefrontal cortex on the control of impulsive behavior

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20856
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0902:General internal medicine and related fields
• Research Institution: Hokkaido University
• Principal Investigator: Sasamori Hitomi 北海道大学, 医学研究院, 客員研究員 (20911126)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 衝動性 / ドパミン / 内側前頭前野

Outline of Final Research Achievements

Major psychiatric disorders such as attention-deficit/hyperactivity disorder and schizophrenia are often accompanied by elevated impulsivity. However, anti-impulsive drug treatments are still limited. To explore a novel molecular target, we examined the role of dopamine D5 receptors in impulse control using mice that completely lack D5 receptors (D5KO mice). We also measured spontaneous activity and learning/memory ability because these deficits could confound the assessment of impulsivity. We found small but significant effects of D5 receptor knockout on home cage activity only at specific times of the day. In addition, an analysis using the q-learning model revealed that D5KO mice displayed lower behavioral adjustment after impulsive actions. However, our results also showed that baseline impulsive actions and the effects of an anti-impulsive drug in D5KO mice were comparable to those in wild-type littermates.

Free Research Field

神経薬理学

Academic Significance and Societal Importance of the Research Achievements

これらの結果は、D5受容体が衝動性制御に必要でないことを示すものであった。また、D5受容体の行動機能を明らかにするためには、時系列で解析することや学習過程の詳細な解析が必要であることが示された。