A research team at HAS' Institute of Experimental Medicine has developed a unique high-speed, three-dimensional laser microscope capable of simultaneous in vivo measurements of the activity of hundreds of neurons, and information transport. Their results were published in the prestigious Nature Methods.

Young Hungarian researchers of the Two-Photon Imaging Centre of HAS' Institute of Experimental Medicine have been developing a new high-speed three-dimensional laser microscope for nearly a decade. During their experiments neurons are filled with a special paint substance that emits light when excited with laser rays. Studying these reactions researchers are able to observe the chemical processes in neurons, and visualise the activity of neural networks in three dimensions. The measuring speed of the Hungarian invention is a million times faster than similar technologies developed so far by giant microscope manufacturing companies. According to their publication in Nature Methods, the research team were able to exceed their own previous record and increase the speed of measurement by several magnitudes, thus highly expanding measurable volumes.

    Increasing their former record of 25-micrometer vertical-axis scanning, published in PNAS in 2011, the young neurologists have recently been able to reach the 3000-micrometer range in spatial measurements. The technology can penetrate a living animal's brain in a depth of 650 micrometers, and measuring speed has also been increased a hundredfold. "We have succeeded in developing a truly unique device. Due to a novel optical technology, we can now follow the activity of hundreds of neurons at the same time, while also measuring the very rapid information spreading processes in the projections of the these cells", said Balázs Rózsa, head of the Two-Photon Imaging Centre.   

   Yet another unique feature of the new device is that it makes it possible to study the operation of neurons in-vivo, i.e. in living organisms. Thanks to this novel technology, Hungarian scientists have been the first to peer into the workings of the brains of living animals. Showing various pictures to necrotised animals starting to awaken, scientists are able to study the operation of the visual cortex. "We can monitor more than 500 neurons in the animal brain at a time, and by repeating the process with different pictures we are able to visualise the workings of tens of thousands of neurons. With this method we can map the activity of a relevant area of the brain in-vivo", the young researcher said. Previous methods allowed neurologists to measure only the average activity of single neurons, while the new microscope is capable to record the activity of both neurons and their projections simultaneously. This new technology could become an indispensable tool in understanding cerebral information processing, as well as contribute to studying the diseases of the central nervous system. Balázs Rózsa believes that their new microscope will revolutionise the entire field of neurology. "It's been only a few days since we published our article, yet it has been  already referenced at international conferences, and our microscope is now among the five best inventions according to Nature Methods".  

     This outstanding achievement has been the fruit of an extensive co-operation between the Two-Photon Imaging Centre of HAS' Institute of Experimental Medicine and the Pázmány Péter Catholic University and a world-renowned Swiss research group led by Botond Roska at the Friedrich Miescher Institute in Basel. Head of the software and electronics team, Gergely Katona has played a crucial role in the development of this complex neurological, optical system, along with Dániel Hillier, Attila Kaszás, Gergely Szalay, and two other researchers of the Budapest University of Technology Pál Maák and Máté Veress.  

     In co-operation with the National Institute of Neurosciences and HAS' Institute of Cognitive Neuroscience and Psychology, the research team has already begun to adapt their technology to clinical applications, which, according to Balázs Rózsa, could lead to a breakthrough in surgery, diagnostics and therapy. 

    The aim of the decade-long research and development is to facilitate high value-added developments in Hungary, from discovery research to actual production of prototypes. The scientists would like to see their new microscope exported to foreign countries as well. In this process, Femtonics Inc., a spin-off company of HAS' Institute of Experimental Medicine, is to play a major role. The extra income generated through export could finance further discovery research and development. Based on their recently published technology, the Hungarian research team's goal is to create the basis for a product family for international export within a year.