Zhang Lin, Yuan Hong-Jin, Cao Bo, Kong Cheng-Cheng, Yuan Fang, Li Jun, Ni Huan-Yu, Wu Hai-Yin, Chang Lei, Liu Yan, Luo Chun-Xia
Department of Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China.
Institution of Stem Cells and Neuroregeneration, Nanjing Medical University, Nanjing 211166, China.
Biochem Biophys Res Commun. 2017 Dec 2;493(4):1560-1566. doi: 10.1016/j.bbrc.2017.09.158. Epub 2017 Sep 30.
Neuronal nitric oxide synthase (nNOS) , mainly responsible for NO release in central nervous system (CNS) , plays a significant role in multiple physiological functions. However, the function of nNOS interneurons in fear learning has not been much explored. Here we focused on the medial ganglionic eminences (MGE) -derived nNOS interneurons in fear learning. To determine the origin of nNOS interneurons, we cultured neurons in vitro from MGE, cortex, lateral ganglionic eminence (LGE) , caudal ganglionic eminences (CGE) and preoptic area (POA) . The results showed that MGE contained the most abundant precursors of nNOS interneurons. Moreover, donor cells from E12.5 embryos demonstrated the highest positive rate of nNOS interneurons compared with other embryonic periods (E11.5, E12, E13, E13.5 and E14). Additionally, these cells from E12.5 embryos showed long axonal and abundant dendritic arbors after 10 days culture, indicating the capability to disperse and integrate in host neural circuits after transplantation. To investigate the role of MGE-derived nNOS interneurons in fear learning, donor MGE cells were transplanted into dentate gyrus (DG) of nNOS knock-out (nNOS) or wild-type mice. Results showed that the transplantation of MGE cells promoted the acquisition of nNOS but not the wild-type mice, suggesting the importance of nNOS neurons in fear acquisition. Moreover, we transplanted MGE cells from nNOS mice or wild-type mice into DG of the nNOS mice and found that only MGE cells from wild-type mice but not the nNOS mice rescued the deficit in acquisition of the nNOS mice, further confirming the positive role of nNOS neurons in fear learning.
神经元型一氧化氮合酶（nNOS）主要负责中枢神经系统（CNS）中一氧化氮的释放，在多种生理功能中发挥重要作用。然而，nNOS中间神经元在恐惧学习中的功能尚未得到充分研究。在这里，我们聚焦于内侧神经节隆起（MGE）衍生的nNOS中间神经元在恐惧学习中的作用。为了确定nNOS中间神经元的起源，我们在体外培养了来自MGE、皮层、外侧神经节隆起（LGE）、尾侧神经节隆起（CGE）和视前区（POA）的神经元。结果表明，MGE含有最丰富的nNOS中间神经元前体。此外，与其他胚胎期（E11.5、E12、E13、E13.5和E14）相比，来自E12.5胚胎的供体细胞显示出nNOS中间神经元的最高阳性率。此外，这些来自E12.5胚胎的细胞在培养10天后显示出长轴突和丰富的树突分支，表明它们在移植后能够分散并整合到宿主神经回路中。为了研究MGE衍生的nNOS中间神经元在恐惧学习中的作用，将供体MGE细胞移植到nNOS基因敲除（nNOS）或野生型小鼠的齿状回（DG）中。结果表明，MGE细胞的移植促进了nNOS小鼠而非野生型小鼠的恐惧习得，这表明nNOS神经元在恐惧习得中具有重要作用。此外，我们将来自nNOS小鼠或野生型小鼠的MGE细胞移植到nNOS小鼠的DG中，发现只有来自野生型小鼠的MGE细胞而非nNOS小鼠的MGE细胞挽救了nNOS小鼠在恐惧习得方面的缺陷，进一步证实了nNOS神经元在恐惧学习中的积极作用。
