High-throughput Two-photon Microscope Developed for Multiparameter and Quantitative Brain Function Imaging

Large-scale recording of multiple dynamic behaviors and quantitative neurochemical concentrations with high spatiotemporal resolution is critical to understand complex brain functions. Two-photon microscopy (TPM) is the excellent choice for brain function imaging because of its high resolution, deep tissue penetration, and favorable biosafety.

However, current TPM is limited by a restricted field-of-view (FOV), an inherent trade-off between the imaging area and temporal resolution, and an insufficient amount of information obtained using only intensity recording.

In a study published in PNAS, a team led by Prof. ZHENG Wei and Prof. YE Shiwei from the Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences developed a large-FOV, dual-region, two-photon fluorescence lifetime imaging microscopy (LD-2P-FLIM) system, which features a large space-bandwidth product (SBP) and high data throughput for multiparametric and quantitative brain function imaging.

LD-2P-FLIM enables large-FOV and high-resolution two-photon imaging using only off-the-shelf optics with an effective adaptive optics strategy. It simultaneously records neural activities in two arbitrarily selected regions across the whole large FOV using temporal multiplexing and two independent scan engines. By a home-made field programmable gate array module, it provides simultaneous two-region fluorescence lifetime images with a data throughput of up to 15.73 megapixels per second.

Benefitting from the large SBP and the high data throughput, researchers conducted various functional brain imaging experiments on awake mice using LD-2P-FLIM. For the first time, they showed its unique capability in the quantitative imaging of calcium concentrations in a large neuronal population.

The findings of this study suggest that LD-2P-FLIM advances functional neural imaging from a qualitative to a quantitative level. The LD-2P-FLIM system provides a new tool for non-invasive brain-computer interface data acquisition.