Fluorescent pipette tips may be beneficial in neuroscience

There are various invasive and non-invasive methodologies of brain investigation that possess certain advantages and drawbacks. Among them we can distinguish imaging techniques that are essential for examination of the networks’ activity in different brain regions, and electrophysiological approaches that are more suitable for local assessment of neuronal activity.

Currently, novel robust methods are used in neuroscience. One of them is labelling of particular neuronal cells basing on their genetic landscape with fluorescent markers. The crucial thing is that apart from visualization and identification of certain cells, it is now possible to alter their activity and observe the changes. The method gives the opportunity to precisely examine chosen cells possessing e.g. some genetic alterations. By electrode-containing glass pipette with very thin tip, the electric activity of fluorescently-labelled neurons residing in deeper parts of the brain can be measured and the influence of genetic changes on electrophysiology can be analyzed.

The major obstacle in the presented method is the fact that the tip of the pipette is not fluorescent and it is not visible under the appropriate microscope when examining labelled cells. Having this on mind, Hungarian researcher, Bertalan Andrásfalvy, together with scientists from Switzerland and USA proposed an innovative approach that utilizes glass pipette covered with semiconductor nanoparticles called Quantum dots (QTs). QTs are becoming very promising tool in life sciences as they possess extraordinary photostability and brightness. Moreover, they are firmly attached to the surface of the pipette tip and the wavelength of the emitted light can be adjusted by choosing their size and composition.

Thanks to the cooperation of the research group with the University of Geneva, it was possible to test fluorescent pipette tip in in vivo experiments. The analyses confirmed that the tool can be successfully used for collecting electrophysiological data for fluorescently-labelled neurons present deep in the brain. Additionally, fluorescent tips were used for delivering plasmids into target cells, which make them promising tool in genetic engineering field.

Bertalan Andrásfalvy is a member of the Momentum Laboratory of Neuronal Signaling led by Judit Makara in the Institute of Experimental Medicine of Hungarian Academy of Sciences.

Sources:

http://hirnforschung.kyb.mpg.de/en/methods.html

http://www.photonics.com/Article.aspx?AID=33995

http://mta.hu/news_and_views/fluorescent-pipette-tips-a-new-tool-for-neuroscientists-135329/

Maciej Smolarz