%A HE Luyao, HUANG Dongping, SHAO Mengmeng, ZHANG Kai, REN Baihui, KONG Qingdan, XU Tianle, LÜ Jiangteng %T Anatomical structure of laminar specific subtypes of medial prefrontal cortex-basolateral amygdala projection neurons %0 Journal Article %D 2022 %J Journal of Shanghai Jiao Tong University (Medical Science) %R 10.3969/j.issn.1674-8115.2022.09.008 %P 1216-1224 %V 42 %N 9 %U {https://xuebao.shsmu.edu.cn/CN/abstract/article_13494.shtml} %8 2022-10-20 %X

Objective ·To dissect the fine anatomical structure of medial prefrontal cortex (mPFC)-basolateral amygdala (BLA) projection neurons based on regional and laminar specificity in the cortex in mice. Methods ·The retrograde tracer of adeno-associated viral (AAV) vectors were injected into BLA of C57BL/6 mice. Twenty-one days after the injection, the mice were sacrificed and the brains were harvested. The coronal sections containing mPFC were prepared by using a cryostat microtome. The images were taken by fluorescence microscopy. Then the representative brain slices containing mPFC were selected and the distribution of virus-labeled cell bodies in different subregions of mPFC was analyzed. By using transgenic mouse lines (Tbr2-CreER::LSL-Flp mice and Rbp4-Cre mice)with Flp- or Cre-dependent AAV, layer 2 (L2) and layer 5 (L5) projection neurons in mPFC and their axons in BLA were marked, respectively. Twenty-eight days after the injection, the mice were sacrificed and the brains were also harvested. Coronal sections of the BLA were collected. The brain slices were imaged by fluorescence microscopy after immunofluorescence staining. By measuring the fluorescence intensity of projecting axons in different regions within BLA, the spatial distributions of the axons in BLA of mPFC L2 and L5 projection neurons were compared. Results ·Through fluorescence microscopy and quantitative analysis, it was found that the cell bodies of BLA projection neurons were mainly located at L2 and L5 in the dorsal mPFC (dmPFC) which contains anterior cingulate cortex and prelimbic cortex. However, the distribution of BLA projection neurons in the ventral mPFC (vmPFC) including medial orbital cortex and infralimbic cortex did not exhibit the similar distribution. When studying the axonal distribution of dmPFC projection neurons in two layers, it was found that the axons of L2 projection neurons dispersed in the BLA, while the axons of L5 projection neurons were mainly located in the dorsal region of BLA. Conclusion ·The cell body distribution of mPFC-BLA projection neurons shows regional specificity and laminar specificity. The axon projections initiated from different layers of dmPFC also exhibit regional specificity in BLA.