Monitoring dynamic metabolic cell interactions in engineered brain tissue models using label-free, multi-modal two photon excited fluorescence

Dynamic metabolic reprogramming among neurons and glial cells can be characterized by label-free two photon excited fluorescence intensity and lifetime (FLIM) imaging of engineered brain tissue models consisting of human neurons, astrocytes, and microglia tri-cultures. Lipofuscin is a significant contributor to the overall fluorescence detected. Its removal is important for accurate recovery of metabolic function metrics. Results reveal the important function of glial cells to reduce oxidative stress in neurons over fourteen weeks of co-culture. Distinct metabolic profiles and dynamic changes are also evident for neurons and glial cells. Our study highlights that engineered brain tissue models in combination with label-free two photon imaging offer an excellent platform for understanding cell-cell interactions and are well-suited to improve understanding of the role of metabolic and mitochondrial dysfunction in neurodegenerative diseases.