University of Tokyo captures new details of cell organization...

Two neuroimaging projects have developed optics-based techniques able to reveal new details of cell dynamics in natural or pharmacologically modified states.

At the University of Tokyo a high-speed microscopy platform capturing individual images rapidly enough to make videos of the dynamic processes occurring inside living cells has been used for high-speed, label-free volumetric chemical imaging.

Described in Nature Communications, the project's mid-infrared photothermal optical diffraction tomography (MIP-ODT) technique exploits the way that absorption of mid-IR light by cells induces local refractive index changes. These changes are then detected by a visible probe beam, creating photothermal contrast imaging data that can be selective to particular chemical bonds.

Integrating MIP with optical diffraction tomography, in which illumination at different incident angles takes place and the scattered light and phase delays are assessed, creates "a platform for high-speed, label-free volumetric chemical imaging at the single-cell level," wrote the UTokyo project in its paper.

Using a spatial light modulator to shape and steer the light lets the platform gather image data at video-rates, while maximising signal-to-noise performance.  

"Previously, three-dimensional mid-infrared photothermal tomography was limited to less than 0.05 images per second, mainly because signal averaging and sequential measurements from different illumination angles required considerable time," commented UTokyo's Masato Fukushima. "We have developed a new technique which achieves 19.2 images per second, enabling us to acquire a complete three-dimensional image every 52 milliseconds, approximately 400 times faster than previous approaches."

This acceleration allows MIP-ODT to track lipid droplets in cultures of living cells and follow diffusion on three-dimensional trajectories, revealing intracellular transport behaviors obscured in previous two-dimensional measurements. 

"Our next step is to address fundamental biological questions that cannot be explored with conventional techniques," noted project leader Takuro Ideguchi. "By visualizing cellular dynamics in three dimensions and over time, we aim to advance toward a quantitative, measurement-driven understanding of life."

Two-photon imaging watches mice get mellow

Researchers at University of California, Santa Cruz have also acquired new views of cell dynamics, this time observing mice brain circuits in vivo as the animals experience the effects of psilocybin.

Psychedelics are of interest to neuroscientists as potent promoters of neuroplasticity and the formation of dendrites and synapses, while also altering neurotransmission.

The potential value of such agents in clinics was confirmed in September 2026 when the US FDA hosted a public hearing on future therapeutic uses of psychedelic drugs.

Any move toward psychedelic-assisted therapies in healthcare will require an understanding of the precise cellular mechanics by which these drugs heal brain circuits, efforts to which UC Santa Cruz has now contributed.

In its Nature Neuroscience paper, UC Santa Cruz employed in vivo two-photon fluorescence imaging of dendritic spines in mice, collecting data before and during ingestion of psilocybin. Dendritic spines are tiny protrusions branching off brain cells and forming synapses with neighboring neurons, and the high-resolution two-photon imaging allowed researchers to track individual dendritic spines in living mouse brain cells across several weeks.

When psilocybin was administered researchers saw a rapid increase in the formation of new dendritic spines within 24 hours, and also watched psilocybin accelerate the physical maturation of these new connections. But psilocybin’s impact depended on the brain's prior exposure to chronic stress.

In healthy control mice the psychedelic induced a temporary boost in new connection formation, followed by a gradual return toward baseline. In mice that had experienced stress, psilocybin sparked a significantly higher surge in new spine formation while simultaneously halting the excessive loss of existing connections.

The data could now help researchers understand in more detail how psilocybin reshapes neural circuits, with implications for treating mental disorders.

"By showing that therapeutic circuit remodeling and hallucinogenic effects operate through distinct cellular pathways, our study provides a promising blueprint for designing non-hallucinogenic drug analogs," said UC Santa Cruz's Yi Zuo. "I consider this work a major advance."