Fluorescing neurons give thoughts away

Heidelberg, Germany--Researchers at the Max Planck Institute for Medical Research are using two-photon laser-scanning microscopy to detect optical changes in neurons, giving them the ability to measure activity patterns such as mental activity and reactions to sensory stimulation.

Neurons communicate with one another via so-called action potentials. During an action potential, voltage-gated calcium channels are opened resulting in rapid calcium ion influx. Because of this tight coupling, fluorescent calcium indicator proteins can visualize action potentials. These proteins have two fluorescent subunits, one of which radiates yellow light and the other blue. When the proteins bind calcium, the proportion of yellow to blue light changes. Color variation from blue light towards yellow thus reports different calcium levels -- which is why the protein has been dubbed a "chameleon."

Measuring action potentials optically
With the chameleon protein YC3.60, a fairly new variant, the scientists succeeded in recording the reaction of nerve cells to sensory stimuli in the intact brain of mice: every time the whiskers were deflected by a puff of air, there was a change of color in the chameleon proteins in the nerve cells of the sensory areas of the cortex. It could therefore be deduced that the affected cells had reacted to the stimulus with action potentials.

The scientists were able to investigate activity in single cells as well as in whole groups of nerve cells. "YC3.60 has therefore proven to be a suitable tool for studying nerve tissue at different levels: on the one hand, we can monitor the fluctuation of calcium to infer action potentials within nerve cells. And what is even more advantageous, we can simultaneously measure the activity of neural networks or entire brain regions," says Mazahir Hasan.

Using fluorescence to study the brain provides a unique opportunity to investigate how memories are formed and lost and, furthermore, when and where nerve-cell activity patterns become altered as in the case of aging and also in neurological diseases such as Alzheimer's disease, Parkinson's disease, and schizophrenia.

 

--posted by John Wallace

Bio-Optics World

Get All the BioOptics World News Delivered to Your Inbox

Subscribe to BioOptics World Magazine or email newsletter today at no cost and receive the latest news and information.

 Subscribe Now
Related Articles

New bioimaging technique offers clear view of nervous system

Scientists at Ludwig-Maximilians University have developed a technique for turning the body of a deceased rodent entirely transparent, revealing the central nervous system in unprecedented clarity....

Fluorescent jellyfish proteins light up unconventional laser

Safer lasers to map your cells could soon be in the offing -- all thanks to the humble jellyfish. Conventional lasers, like the pointer you might use to entertain your cat, produce light by emittin...

Fluorescence microscopy helps provide new insight into how cancer cells metastasize

By using fluorescence microscopy, scientists have discovered an alternate theory on how some cancer cells metastasize.

In vivo imaging method visualizes bone-resorbing cell function in real time

In vivo imaging can visualize sites where osteoclasts (bone-resorbing cells) were in the process of resorbing bone.

BLOGS

Neuro15 exhibitors meet exacting demands: Part 2

Increasingly, neuroscientists are working with researchers in disciplines such as chemistry and p...

Why be free?

A successful career contributed to keeping OpticalRayTracer—an optical design software program—fr...

LASER Munich 2015 is bio-bent

LASER World of Photonics 2015 included the European Conferences on Biomedical Optics among its si...

White Papers

Understanding Optical Filters

Optical filters can be used to attenuate or enhance an image, transmit or reflect specific wavele...

How can I find the right digital camera for my microscopy application?

Nowadays, image processing is found in a wide range of optical microscopy applications. Examples ...

CONNECT WITH US

            

Twitter- BioOptics World