Neurobiology and Neurodevelopment

The brain is notoriously challenging to study. It is composed of countless small cells spread throughout a considerably large organ, often necessitating a trade-off between imaging the entire brain and achieving high-resolution images. However, techniques like brain expansion physically expand brain tissue to overcome the resolution issue by increasing the sample rather than having to decrease resolution.

Another challenge in brain imaging is that in most organisms, the brain is not transparent but opaque, reducing light penetration and thus impacting imaging beyond the surface. To overcome this hurdle, tissue clearing can be used. Tissue clearing renders tissues transparent, enabling light penetration and imaging within the tissue. This allows the visualization of intricate neural networks and other brain structures.

The spinal cord

The spinal cord plays a central role in transmitting signals between the brain and the rest of the body, influencing essential functions such as movement, sensation, and organ control. Advances in spinal cord research hold the promise of unlocking new treatments and therapies for spinal cord injuries, paralysis, and neurological disorders.

The eye

Eye research is important to understand and prevent vision loss, but eye research is also often used as a proxy to understand the brain. The eye is a peripheral part of the brain but has much greater accessibility and shares numerous similarities with the brain in terms of cell types, functionality, and cell-to-cell interactions. This structural and functional resemblance makes the eye an invaluable model for fundamental biological processes and serves as a bridge to wider neurology applications. 

Zebrafish Eye

Zebrafish eye imaged on the MuVi SPIM.

Courtesy of:
Anja Machate and Michael Brand
Center for Regenerative Therapies Dresden (CRTD), TU Dresden
Dresden, Germany

By studying the peripheral nervous system (PNS), scientists gain unprecedented access to the intricate details of peripheral nerves. This not only aids in mapping the structural intricacies of nerve fibers, but also allows for the visualization of dynamic processes crucial for understanding neural function. Biomedical imaging serves as an invaluable tool in elucidating the connectivity between the PNS and the brain, enabling the tracing of neural pathways and the investigation of how information is transmitted and processed. Moreover, studying the PNS is pivotal in diagnosing and monitoring neurological disorders that may manifest in both peripheral nerves and the brain. This integrated approach offers insights that are instrumental in advancing medical diagnostics, treatment strategies, and overall neurological research.

The brain's role as the body's central control hub makes understanding its health of paramount importance. Despite the challenges posed by its complexity, innovative techniques and approaches are continually advancing our understanding of brain structure and function, paving the way for breakthroughs in brain development and neurobiology research. This knowledge is crucial for improving the diagnosis and treatment of neurological disorders, ultimately enhancing the overall well-being of individuals.

Microglia Response to Axonal Damage

The axon of a neuron in the zebrafish brain was selectively dissected by means of IR laser ablation (MuVi SPIM). Thirty minutes after ablation, four microglia reached the damaged axon.

Image taken from:
de Medeiros, G., Kromm, D., Balazs, B. et al. Cell and tissue manipulation with ultrashort infrared laser pulses in light-sheet microscopy. Sci Rep 10, 1942(2020). https://doi.org/10.1038/s41598-019-54349-x

Microglia Movement

Microglia movement in zebrafish. The vascular system is labeled with a cyan marker and microglia with a yellow one. Imaged on the QuVi SPIM at 2 FPS for 20 min. Two orthogonal views fused and max. project.

Courtesy of:
N. Norlin, F. peri
European Molecular Biology Laboratory (EMBL)
Heidelberg, Germany