Li Zhuo, Qu Yu, Wu Qi-Lin, Tang Li, Dong Yuan, Xu Xu-Feng
Basic School of Medicine, Qingdao Medical College, Qingdao University, Qingdao, China.
Institute of Neuropsychiatric Diseases, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.
Front Neurosci. 2025 Feb 19;19:1532078. doi: 10.3389/fnins.2025.1532078. eCollection 2025.
The infralimbic cortex (IL), a critical subregion within the ventromedial prefrontal cortex (vmPFC), modulates emotion, memory, and social functions via robust projections to the basolateral amygdala (BLA). However, the afferent brain regions that innervate BLA-projecting IL neurons (IL-BLA PNs) and their efferent targets have not been systematically characterized.
We employed tracing techniques integrating adeno-associated virus (AAV) and monosynaptic rabies to systematically investigate the presynaptic inputs and axonal outputs of IL-BLA PNs.
Our findings revealed widespread synaptic inputs to IL-BLA PNs from subcortical areas, with the strongest inputs originating from the dorsomedial thalamus (MD) and anterior medial thalamus (AM) in the thalamic region, as well as from the ventral hippocampus (vHPC) and piriform cortex (Pir) in the limbic system. Sparse labeling of the virus demonstrated that IL-BLA PNs collateralize to innervate various subcortical regions, including the horizontal diagonal band (HDB), lateral preoptic area (LPO), ventral pallidum (VP), and lateral hypothalamus (LH).
This work establishes essential theoretical frameworks for the functional investigation and targeted intervention in neurological disorders.
边缘下皮质（IL）是腹内侧前额叶皮质（vmPFC）内的一个关键亚区域，通过向基底外侧杏仁核（BLA）发出强大投射来调节情绪、记忆和社会功能。然而，支配投射至BLA的IL神经元（IL-BLA PNs）的传入脑区及其传出靶点尚未得到系统的表征。
我们采用整合腺相关病毒（AAV）和单突触狂犬病的追踪技术，系统地研究IL-BLA PNs的突触前输入和轴突输出。
我们的研究结果揭示了来自皮质下区域的对IL-BLA PNs广泛的突触输入，丘脑区域中最强的输入来自背内侧丘脑（MD）和前内侧丘脑（AM），以及边缘系统中的腹侧海马（vHPC）和梨状皮质（Pir）。病毒的稀疏标记表明，IL-BLA PNs发出侧支支配包括水平对角带（HDB）、外侧视前区（LPO）、腹侧苍白球（VP）和外侧下丘脑（LH）在内的各种皮质下区域。
这项工作为神经系统疾病的功能研究和靶向干预建立了重要的理论框架。
