Multi-scale imaging and recording of in-vivo neural activity.

Most in vivo neural technologies have been developed to enhance the resolution of subcellular neuronal activity or to expand the spatial range for tracking ensembles of neurons in the brains of live animals. While these approaches offer great promise for understanding cellular and circuit functions in behaving mammals, their cross-sectional observations are inherently limited in accounting for causal interactions of neural dynamics across various scales of brain architecture. Consequently, the simultaneous observation of multi-scale neural activity has emerged as a crucial strategy for achieving a more comprehensive understanding of brain function. These advancements facilitate the simultaneous detection of diverse signals, providing unprecedented insights into dynamic neurophysiological mechanisms within three-dimensional brain structures that remain poorly understood. Here, we review state-of-the-art technologies for the parallel observation of multiple neural targets in vivo. We highlight strategies for simultaneously observing brain signals at multiple resolutions, aiming to bridge the spatiotemporal gaps between microscopic and macroscopic domains of neurobiology. We also emphasize the technical integration of neural tools to concurrently acquire electrophysiological activity and optical imaging, leveraging their complementary strengths. Finally, we discuss the future challenges and potential prospects of multimodal neural techniques, paving the way for a deeper understanding of brain functions and disorders. [BMB Reports 2026; 59(2): 124-136].