薛天 
Tian Xue 

Ph.D. Professor 
University of Science and Technology of China (USTC), China

博士，中国科学技术大学人力资源部部长，生命科学与医学部执行部长，生命科学学院教授、博导，微尺度物质科学国家研究中心“神经环路与脑认知部”主任。长期从事光感受神经生物学的光信号转导、神经环路以及视觉再生修复等方面研究。

研究方向

• 生命体如何感光-光感受的信号转导机制，特别是自感光视网膜神经节细胞（ipRGCs）的光信号转导机制。
• 光调控生命体生理功能-非成像视觉神经环路，如夜间异常光诱发抑郁样表型的神经环路结构与功能。
• 探索基因编辑、干细胞技术和纳米新材料在大动物模型中治疗视网膜感光细胞退化疾病中的应用。如结合视觉神经生物医学与纳米技术，首次实现哺乳动物裸眼红外图像视觉；对于视觉神经系统遗传性疾病，采用在体同源重组的基因编辑技术，挽救感光细胞退化小鼠视觉；解析人类与非人灵长类恒河猴视网膜衰老分子图谱；建立首例非人灵长类视网膜色素变性猕猴模型等。

Research Field of Interest

Phototransduction, Non-Image Vision, Stem Cell, Photoreceptor Regeneration

Description

Responding to the surrounding environment is one of the vital traits of a living organism. In particular sensing light is a most important perception and way of gathering information for most organisms. Dr. XUE’s lab is hence interested in understanding physiological characteristics and signaling mechanisms of photo-sensation, revealing neural circuits involved in this process and exploring methods for vision restoration after photoreceptor degeneration. “Light” does not only convey image information (image-forming vision), but also has impact on a number of physiological functions, such as light-entrainment of circadian rhythm, mood regulation, sleep, negative masking, pupillary light reflex, melatonin secretion etc. – functions referred to collectively as non-image vision (NIV). Only until recently, we realized that NIV is mediated by a special group of light-responsive cells in the retina: intrinsically photo-sensitive retinal ganglion cells (ipRGCs).

1. Neuronal Circuitry Involved in NIV 
As compared to classic image-forming vision, we have very limited knowledge regarding the neuronal circuits involved in NIV. On-going projects in Dr. Xue’s lab focus on the mesoscopic structure and function of NIV-associated neuronal circuitry, using techniques such as trans-synaptic viral tracing, electrophysiology, optogenetics, and in vivo deep-brain calcium imaging. 

2. Vision Rescue 
Perception of light is of great importance, thus restoration of damaged photoreception (especially blindness caused by degeneration of rods and cones) is of high clinical value. One research direction of Dr. XUE’s lab is to explore the possibilities in vision repair and rescue with a combinatorial approach employing stem cell regeneration (3D retinal organoids), gene editing (CRISPR/Cas9 or base editing technologies), and bio-informatics (high-throughput sequencing and analysis). 

3. Photo-transduction Mechanisms and Neuronal Coding Underlying NIV 
It is still not fully clear how ipRGCs control the unique kinetics of its light response through photo-transduction mechanisms, and what physiological significance this has for neuronal coding of NIV. We aim to investigate molecular targets that may affect the kinetics of ipRGC-mediated photo-responses, with the aid of transgenic mice, AAV-RNAi, patch-clamp and optogenetic techniques. We will further combine in vivo optogenetics with behavioral tests to reveal the coding pattern of ipRGC-mediated information, and its impact on NIV-associated physiological processes. This will expand our understanding about the strategy used by neural systems to code environmental stimuli for different physiological needs.