小鼠视知觉训练提高视功能的神经基础和分子机制

Vision with normal function is one of the important factors affecting the people profession selection on employment, quality of life and the pursuit of happyness. Amblyopia is the most common clinical cause of visual impairment, but no effective therapy is available for adult amblyopic. Recently, perceptual learning has been shown to be effective in improving visual functions in adult patients with amblyopia, even in normal adults, however, the mechanism underlying the treatment is unclear. In this study, we build up a home-made water maze to train the mice with the visual perceptual training protocol which mimics the clinic procedures. With this animal model, we investigate the alteration of visual circuitry in visual pathway in combination with multi-electrode arrays recording, intrinsic optical imaging and two-photon imaging in vivo. With the optogenetics manipulation which selectively control neuron firings in different brain areas, we investigate the role of the feed-back circuitry from prefrontal cortex in visual perceptual learning.After screening differently expressed long non- coding RNA（lncRNA）in visual cortex between perceptual traing and control animals and using RT-PCR, pharmacology and histology, we study the molecular mechanisms underlying the improvement of visual functions after perceptual training. Moreover, our previous findings reveal that several treatments restore the plasticity at adulthood. We further explore the effect of the combination treatment. These findings will provide the therapeutic mechanisms of perceptual training in the animal model, establish the theoretical foundation of clinical application and provide new research clues of the developed therapy for adult amblyopic.It will also shed some light on the neural mechanism underlying the cognitive function of brain and the plasticity in adulthood.

正常的视觉功能是影响人们就业选择、生活质量与幸福感的重要因素之一。弱视是临床上最常见引起视觉功能下降的病因，但成人弱视无有效的治疗手段。近年来视知觉训练被证实可有效提高成人弱视患者甚至正常人群的视功能，但其机制尚不清楚。通过自制的水迷宫训练装置，我们模拟临床视知觉训练方法，建立小鼠视知觉学习的行为学模型；同时结合在体光学成像、双光子成像和多导电生理技术研究知觉训练对各级视皮层的影响；用光遗传学研究包括前额叶皮层等高级脑区反馈环路的贡献；利用分子生物学（长链非编码RNA差异表达等）、药理学以及形态学等手段，研究视知觉学习改善视觉功能的细胞和分子机制；最后结合已有的提高成年可塑性的手段，进一步开发出更加高效的综合治疗方法。动物模型的建立及其相关机制的阐明不仅有助于进一步了解大脑基本认知功能和成年可塑性,还将为成人患者弱视的知觉治疗手段提供了理论基础和依据，并能为将来技术的改进提供可靠的线索。

视知觉训练被证实可有效提高成人弱视患者甚至正常人群的视功能，但机制未知。我们在小鼠上模拟临床视知觉训练方法建立视知觉学习的行为学模型，在此基础上探究参与知觉学习的脑区以及分子信号通路，同时开发在成年个体恢复可塑性的技术，寻找治疗成年弱视的可能途径。.主要成果如下：（1）通过自制的水迷宫训练装置，我们首次建立了小鼠的视知觉学习模型，经过训练后小鼠视力提高了近40%；（2）小鼠知觉学习效果具有眼传递性和方位传递性，但在简单和复杂视觉任务间只有单向传递性，均与人上结果类似；（3）在体光学成像、光遗传学和电生理记录揭示初级视觉皮层和前额叶皮层mPFC都是知觉学习的关键脑区；（4）mRNA的差异表达揭示多个分子信号通路参与了视知觉学习和视觉可塑性的消退，例如知觉学习会下调GABA抑制系统，而后者可在成年个体恢复幼年样的可塑性；（5）发现促肾上腺素皮质激素释放激素（CRF）及其受体在知觉训练过程中下调并易化知觉学习效果；（6）发现多巴胺I型受体易化早期知觉学习并延缓学习效果的遗忘，同时在知觉学习反转学习的早期起着重要作用，而应激经验则对反转学习的晚期起作用；（7）发现NMDA受体NR2B亚基调控成年视觉可塑性的提高；（8）利用知觉学习和提高成年可塑性的手段均可有效治疗弱视小鼠的视力与视功能。部分结果已在Mol Brain、Neuropharmacology等上发表通讯作者SCI论文6篇，并还有数篇在投以及邀稿综述文章。这些工作不仅有助于进一步了解大脑基本认知功能和成年可塑性,还将为成人患者弱视的知觉治疗手段提供了理论基础和依据。此外，我们还研发了微型荧光显微镜的在体记录系统和半自动透镜埋藏手术装置，将用于小鼠行为过程中脑神经元钙成像研究；而透镜包被技术则打破国外公司对此的技术垄断。