Holograms Used To Observe Brain Function

Advanced Imaging Specialists from Switzerland’s EPLF and CHUV have published a study in the Journal of Neuroscience, on the neuro-activity in the brain. With powerful equipment that can see microscopic organisms at 150 times greater resolution than normal microscopes -and in 3D, teams of neurobiologists, psychiatrists and imaging specialists have been able to watch brain activity up close and personal.

By utilizing this type of advanced technology for research, the incredible potential for the development and testing of new drugs to fight neurological diseases, such as Alzheimer’s and Parkinson’s, can be advanced.

Scientists have had to use florescent dyes in a Petri dish in order to observe neurons, which are transparent and come in various shapes and sizes. The lights change the chemical properties of the neurons, which could cause the data to become compromised. It is also time consuming, could cause damage to the cells, and can only allow the researcher to examine a few neurons at a time. Digital Holographic Microscopy (DHM) allows real time observation and does not alter the neurons, or the results, in any way.

“DHM is a fundamentally novel application for studying neurons with a slew of advantages over traditional microscopes,” explains Pierre Magistretti of EPFL’s Brain Mind Institute and a lead author of the paper. “It is non-invasive, allowing for extended observation of neural processes without the need for electrodes or dyes that damage cells.”

Senior team member Pierre Marquet added, “DHM gives precious information not only about the shape of neurons, but also about their dynamics and activity, and the technique creates 3D navigable images and increases the precision from 500 nanometers in traditional microscopes to a scale of 10 nanometers.”

As an example: imagine a large rock sitting on the ocean floor. As waves swirl around the rock the waves send out information about the rock’s shape. You can get this information by comparing to waves that did not have to smash up against the rock, and receive a visual image of the rock shape. By pointing a single wavelength at an object, DHM can do this with a laser beam, collecting the distorted images on the other side and comparing it to a reference beam. The laser beam travels through the transparent cells and relays important information about their internal structures. A computer then numerically reconstructs a 3D image of the object – in this case neurons – using an algorithm d the authors have developed.

Along with Christian Depeursinge, DHM pioneer and EPFL professor in the Advanced Photonics Laboratory, Magistretti decided to apply the process normally used to find defects in minute materials for neurobiological applications. Their group induced an electric charge into a culture of neurons using the main neurotransmitter in the brain, glutamate. This charge transfer carries water inside the neurons and changes their optical properties in a way that can be detected only by DHM. In this way the technique accurately visualizes the electrical activities of hundreds of neurons simultaneously, in real-time, without damaging them with electrodes. There is also no need to inject dyes or electrodes, so DHM can be applied to the screening of thousands of new pharmacological molecules.

With this method new molecules will be able to be tested in larger quantities, faster than they could before. Important ramifications that can be developed through the use of DHM in the discovery of new drugs to combat or prevent neuro-degenerative diseases such as Parkinson’s and Alzheimer’s.

“Due to the technique’s precision, speed, and lack of invasiveness, it is possible to track minute changes in neuron properties in relation to an applied test drug and allow for a better understanding of what is happening, especially in predicting neuronal death,” Magistretti says. “What normally would take 12 hours in the lab can now be done in 15 to 30 minutes, greatly decreasing the time it takes for researchers to know if a drug is effective or not.”

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About the author:

Ron White is a two-time U.S.A. Memory Champion and memory training expert. As a memory keynote speaker he travels the world to speak before large groups or small company seminars, demonstrating his memory skills and teaching others how to improve their memory, and how important a good memory is in all phases of your life.


Science Daily: Holograms Reveal Brain’s Inner Workings: Microscopy Technique Used to Observe Activity of Neurons Like Never Before:  http://www.sciencedaily.com/releases/2011/08/110816171734.htm

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