펨토초빛을 이용한 신경세포 자극방법

학위논문 (박사)-- 서울대학교 대학원 : 협동과정뇌과학전공, 2015. 8. 전누리.The paradigm of experimental models in modern neuroscience and neural engineering has been rapidly evolving from 2D to 3D environments. A variety of techniques have emerged as important tools for controlling action potential firing of a single neuron in 3D environments. Here, we report that a focused femtosecond light activates an unmodified neuron in a 3D environment, producing repetitive action potentials without insertion of any external materials. To further characterize this method, a new microfluidic system was developed to optically stimulate a neuron and electrically record its signals for a long duration. This was combined with the microfluidic technique and electrode measurement under the microscope. This approach allowed precise and rapid stimulation of a single neuron at multiple points, and systematic analyses of neural and axonal responses using a spike sorting technique. We assessed the property, efficiency, and safety of this optical stimulation using the focused femtosecond light. We also demonstrated that the femtosecond light stimulated a neuron successfully in 3D environments. Furthermore, the studies on the underlying mechanism indicated that the neural response to femtosecond light was caused by intracellular calcium elevation from the internal calcium store through supra-threshold excitation of the soma. Although several factors remain to be determined regarding femtosecond light irradiation, we expect that this technique will avoid many of the problems inherent to electrodes, such as invasiveness and lack of specificity, and thus, could aid in scientific discoveries and in engineering experimental approaches. Furthermore, the femtosecond light coupled with an appropriate optical probe can be employed for in vivo neural stimulation. This may lead to new therapeutic approaches with rapid optical regulation of excitation and inhibition without genetic modification and external interruption of the cellular function.Chapter 1. Introduction 9 Chapter 2. Methodology 20 Chapter 3. Optimum visible light parameters for focal photolysis of commercial caged glutamate to evoke neuronal action potentials 33 Chapter 4. Endogenous neural stimulation using the focused femtosecond laser 49 Chapter 5. Conclusion 90 Bibliography 93 Abstract 104Docto

(An) Efficient Handoff Mechanism for Reducing Latency in Hierarchical Mobile IPv6

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Development of hybrid culture platform and system towards mimicking in vivo model of neural networks

학위논문(석사) --서울대학교 대학원 :협동과정뇌과학전공,2010.2.Maste

An Efficient Handoff Mechanism with Reduced Latency in Hierarchical Mobile IPv6

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고체산화물 연료전지용 전해질과 음극재의 기계-화학적 공소결 거동

학위논문(박사) - 한국과학기술원 : 신소재공학과, 2009.2, [ v, 126 p. ]한국과학기술원 : 신소재공학과