MRI imaging studies for disease differentiation using animal models of PTSD and depression

2022 Fiscal Year Final Research Report

• Project/Area Number: 17K18711
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Psychology and related fields
• Research Institution: Kyoto Prefectural University of Medicine
• Principal Investigator: Yoshii Takanobu 京都府立医科大学, 医学(系)研究科(研究院), 講師 (50468261)
• Project Period (FY): 2017-06-30 – 2023-03-31
• Keywords: ストレス / PTSD / MRI / VBM / WKY

Outline of Final Research Achievements

We utilized Wistar-Kyoto (WKY) rats and subjected them to single-prolonged stress (SPS) under two different conditions: solitary housing and pair housing. The rats were then compared using behavioral analysis and structural MRI. As a result, the Wistar rats in the pair housing condition exhibited significant behavioral changes following SPS, whereas no significant changes were observed in the solitary housing condition. Similarly, the expected pathological changes were not observed in the WKY rats. In terms of structural MRI, the solitary housing SPS group showed shrinkage in the right visual cortex, whereas the WKY rats in solitary housing with SPS displayed enlargement in the medial prefrontal cortex, somatosensory cortex, auditory cortex, and amygdala.

Free Research Field

神経科学

Academic Significance and Societal Importance of the Research Achievements

本研究のWistarラットにおけるSPS負荷後の視覚野の萎縮は先行研究（Yoshii et al., 2017）と一致しており、視覚野がストレス感受性領域である可能性が検証された。一方、WKYラットにSPSを負荷した結果、内側前頭前野・体性感覚野・聴覚野・扁桃体が肥大していることが判明した。WKYとWistarの遺伝的差異がストレス後の脳の形態変化に大きな影響を与えることが示唆された一方で、遺伝的要因による脳のストレス後の肥大は報告がほとんどなく、この結果はPTSDなどの疾患における臨床研究での萎縮部位の報告が一致しない要因となる可能性がある。