Articles

  • the Korean Society for Brain and Neural Sciences

Article

Original Article

Exp Neurobiol 2017; 26(3): 158-167

Published online June 30, 2017

https://doi.org/10.5607/en.2017.26.3.158

© The Korean Society for Brain and Neural Sciences

Functional Characterization of Resting and Adenovirus-Induced Reactive Astrocytes in Three-Dimensional Culture

Junsung Woo1,2,3†, Sun-Kyoung Im4†, Heejung Chun1,2, Soon-Young Jung2, Soo-Jin Oh1,2,3, Nakwon Choi5,6, C. Justin Lee1,2,3,7* and Eun-Mi Hur1,4,7*

1Center for Neuroscience, Korea Institute of Science and Technology (KIST), Seoul 02792, 2Functional Connectomics, Korea Institute of Science and Technology (KIST), Seoul 02792, 3Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul 02792, 4Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology (KIST), Seoul 02792, 5Center for BioMicrosystems, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, 6Division of Bio-Medical Science &Technology, KIST School, Korea University of Science and Technology, Seoul 02792, 7Department of Neuroscience, Division of Bio-Medical Science &Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea

Correspondence to: *To whom correspondence should be addressed.
C. Justin Lee, TEL: 82-2-958-6940, FAX: 82-2-958-6937, e-mail: cjl@kist.re.kr
Eun-Mi Hur, TEL: 82-2-958-6856, FAX: 82-2-958-6937, e-mail: ehur@kist.re.kr
These authors contributed equally

Received: June 8, 2017; Revised: June 16, 2017; Accepted: June 16, 2017

Abstract

Brain is a rich environment where neurons and glia interact with neighboring cells as well as extracellular matrix in three-dimensional (3D) space. Astrocytes, which are the most abundant cells in the mammalian brain, reside in 3D space and extend highly branched processes that form microdomains and contact synapses. It has been suggested that astrocytes cultured in 3D might be maintained in a less reactive state as compared to those growing in a traditional, two-dimensional (2D) monolayer culture. However, the functional characterization of the astrocytes in 3D culture has been lacking. Here we cocultured neurons and astrocytes in 3D and examined the morphological, molecular biological, and electrophysiological properties of the 3D-cultured hippocampal astrocytes. In our 3D neuron-astrocyte coculture, astrocytes showed a typical morphology of a small soma with many branches and exhibited a unique membrane property of passive conductance, more closely resembling their native in vivo counterparts. Moreover, we also induced reactive astrocytosis in culture by infecting with high-titer adenovirus to mimic pathophysiological conditions in vivo. Adenoviral infection induced morphological changes in astrocytes, increased passive conductance, and increased GABA content as well as tonic GABA release, which are characteristics of reactive gliosis. Together, our study presents a powerful in vitro model resembling both physiological and pathophysiological conditions in vivo, and thereby provides a versatile experimental tool for studying various neurological diseases that accompany reactive astrocytes.

Keywords: 3D culture, reactive astrocyte, adenovirus, functional characterization, passive conductance, tonic GABA current