Researchers have developed a method to manipulate and monitor the activity of brain tissue artificially grown outside the body. The National Research Foundation of Korea (President Lee Kwang-bok) reported that "a joint research team of Dr. Choi Nak-won and Dr. Kim Hong-nam of the Korea Institute of Science and Technology (KIST), in collaboration with Professor Bang Seok-young of Dongguk University, has successfully created a directional neural network in a three-dimensional environment outside the body for the first time in the world, and has demonstrated that local neural regulation is feasible by delivering drugs that can stimulate or inhibit neural signals through microfluidic microchannels." 

Our body's organs and tissues are arranged in a directional state with various elements besides cells, and the brain's neural circuits also have a directional state. Previous attempts to emulate the features of the brain's neural circuits outside the body and study them were hindered by the lack of technology that could locally regulate specific parts of the formed neural circuits, resulting in limitations in the research on physiological/pathological models outside the brain. Therefore, it was essential to create an external model with a system that can locally regulate directional brain neural circuits.

The collaborative research group devised a three-dimensional cerebral neural tissue chip fabrication technique that can concurrently implement a method of orienting collagen microfibres to induce neurons in cerebral neural tissues to proliferate in a specific direction, and incorporate microfluidic microchannels that enable various biochemical factors to flow into the formed tissue. Moreover, they proposed a method of regulating signal transmission in cerebral neural networks by stimulating and inhibiting local regions of the formed cerebral neural tissue by flowing various types of drugs into the microfluidic microchannels.

Kang Hyun-wook, a master's-doctoral integrated course student (Department of Mechanical Engineering, Korea University), who is the co-first author of this study, said, "Through this technique, which is the world's first to form cerebral neural tissue and monitor signal transmission in networks through local stimulation and inhibition, we have demonstrated the potential of conducting physiological/pathological research through precise analysis of cerebral neural circuits." He elucidated the significance of this study.

Dr. Choi Nak-won, co-corresponding author, said, "In this study, we formed cerebral neural tissue aligned in a single direction and modulated neurons within the network through drugs, but I think it will be a system that can assist physiological/pathological research more if we expand the range of imitation and form cerebral neural tissue that mimics a higher degree of form." He introduced the remaining tasks.

Schematic of the developed in vitro platform, neural network formation and neural stimulation through local delivery of chemicals

[Reference] Jeong. et al., (2023) “ Integration of reconfigurable microchannels into aligned three-dimensional neural networks for spatially controllable neuromodulation” 

[Main Author] So Hyeon Jeong (Mepsgen), Hyun Wook Kang (KIST), So Hyun Kim (SK Biopharm), Seok Young Bang (Dongguk University), Hong Nam Kim (KIST), Nakwon Choi (KIST)

* Contact : Dr. Nakwon Choi (KIST) (nakwon.choi@kist.re.kr)