On Thursday 1st August 2024, Prof. Tomáš Čižmár from Friedrich-Schiller University of Jena and Head of the Fibre Research and Technology department of the Leibniz Institute of Photonic Technology (IPHT) in Jena, Germany, visited the AOG. As well as receiving a tour of the labs and discussing potential future collaborations, he gave a talk on “Seeing anywhere in the brain through 100 mm thin glass fibre”.
Abstract: Light-based in-vivo brain imaging relies on the transportation of light through highly scattering tissues over long distances. As scattering gradually reduces imaging contrast and resolution, it becomes challenging to visualize structures at greater depths, even when using multiphoton techniques. To overcome this limitation, minimally invasive endomicroscopy techniques have been developed that typically use graded-index rod lenses.
However, a recently proposed alternative involves the exploitation of holographic control of light transport through multimode optical fibres [1], which promises superior imaging performance with less traumatic application [2]. Following the review of the fundamental and technological bases, the talk will introduce a 110 μm thin laser-scanning endo-microscope, which enables volumetric imaging of the entire depth of the mouse brain in vivo [3]. The system is equipped with multi-wavelength detection and three-dimensional random-access options, and it has a lateral resolution of less than 1 μm. Various modes of its application will be presented including the observations of fluorescently labelled neurons, their processes, and blood vessels. Finally, the use of the instrument for monitoring calcium signalling and measurements of blood flow in individual vessels at high speeds will be discussed.
References
[1] T. Čižmár, and K. Dholakia. “Exploiting multimode waveguides for pure fibre-based imaging.” Nature communications 3.1 (2012): 1027.
[2] S. Turtaev, et al., High-fidelity multimode fibre-based endoscopy for deep brain in vivo imaging. Light-Science & Applications 7, 92 (2018).
[3] M. Stibůrek, et al., 110μm thin endo-microscope for deep-brain in-vivo observations of neuronal connectivity, activity and blood flow dynamics. Nature Communications, (in print,
2023).
Biography: Tomáš Čižmár is a professor of Wave Optics at the Friedrich-Schiller University of Jena and the head of the Fibre Research and Technology department of the Leibniz Institute of Photonic Technology (IPHT) in Jena. He leads the Holographic Endoscopy group at IPHT and the group of Complex Photonics at the institute of Scientific Instruments in Brno. Although his scientific background is Physics, throughout his scientific career he took part in a variety of inter-disciplinary projects in Bio-Medical Photonics, mostly related to optical manipulation, digital holography, and microscopy. His recent research activities are focused on Photonics in optically random environments (particularly multimode fibres) and deep-tissue in-vivo imaging.
After presenting in Kent, we heard that Professor Čižmár was awarded a prestigious prize by the European Microscopy Society.
Check articles about Dr. Tomas Čižmár’s Life Sciences award from the following links:
EMS Awards | EMC2024
EMS News 84.pdf (eurmicsoc.org)
Tomáš Čižmár převzal významné evropské ocenění voboru mikroskopie – Akademie věd České republiky
(avcr.cz)