Please give a lot of attention and participation from the members of the Mechanical Engineering department.

▣ Title : Microsystems for studying neural circuits in-vivo & in-vitro

▣ Speaker: Dr. Iljoo Cho

▣ Affiliation: KIST

▣ Date: 2021. 12. 3.(Fri) 17:00

▣ Venue: Engineering Building D403

▣ Host: Prof. Jongbaeg Kim

▣ Abstract

Investigation and modulation of neural circuits in vivo & in-vitro at the cellular level are essential for studying functional connectivity in a brain. Recently, neural probes with stimulation capabilities have been introduced, and they provided an opportunity for studying neural activities at a specific region in the brain using various stimuli. However, previous methods have a limitation in dissecting long-range neural circuits due to inherent limitations on their designs. Moreover, the large size of the previously reported probes induces more significant tissue damage. Herein, we present a multifunctional multi-shank MEMS neural probe that is monolithically integrated with an optical waveguide for optical stimulation, microfluidic channels for drug delivery, and microelectrode arrays for recording neural signals from different regions at the cellular level. In this work, we successfully demonstrated the functionality of our probe by confirming and modulating the functional connectivity between the hippocampal CA3 and CA1 regions in vivo. Also, we recently demonstrated that the neural probe system could be used to investigate neural circuit dynamics in neural circuits implemented in a 3D cell-culture platform. Furthermore, we applied the system to the monitoring neural activities in various brain organoids with the delivery of chemicals for activation or suppression of neural activities. In addition, we developed a lensless multicolor fluorescence microscope system for monitoring dynamic cell movement. The system was implemented with a small form factor, which enabled monitoring of cell dynamics in an incubator. We believe that these microsystems will play key roles in studying neural circuits in-vivo and in-vitro.