2014 Finalist Ho Ko, Ph.D. Lui Che Woo Institute of Innovative Medicine The Chinese University of Hong Kong
Ho Ko received his undergraduate degree in medical sciences from the Chinese University of Hong Kong (CUHK) under the supervision of Wing-Ho Yung in 2008. Under the mentorship of Thomas Mrsic-Flogel, he received his Ph.D. in neuroscience from the University College London (UCL) in 2012. At UCL, he worked closely with Sonja Hofer and Lee Cossell, and developed an experimental approach for studying the organization and development of synaptic connectivity with respect to neuronal function in the visual cortex. Ho Ko is currently at CUHK, where he is pursuing clinical training while conducting research work studying the neural basis of motor control and visual information processing, as well as planning collaborative work with engineers to develop novel biomedical engineering technology.
Functional organization of synaptic connections in the neocortex
Uncovering how connectivity in the cortex is organized with respect to the functionality of neurons is crucial to understanding the physical realization of computation by the brain. During his Ph.D. in the laboratory of Thomas Mrsic-Flogel, Ho Ko developed an experimental technique to relate the sensory feature selectivity of neurons to their connectivity in mouse neocortex. He discovered that in layer 2/3 of the primary visual cortex (V1), excitatory pyramidal neurons with more similar feature selectivity are more likely to be connected, forming functional microcircuits. He also found that this specific connectivity emerges after the onset of visual experience, and visual experience is partially required for the complete maturation of functionally specific connectivity in V1. In contrast to pyramidal neurons, fast-spiking parvalbumin-expressing interneurons in V1 receive strong and dense non-specific local excitatory input, hence explaining their overall broad tuning to visual features. These results are the first steps in revealing the functional, synaptic organization of cortical circuits and providing a circuit-level mechanism of how individual neurons, and the ensembles they form, represent visual information.
For Dr. Ko‘s full essay, see Science online at sciencemag.org.