MIT scientists have come up with a new technique that shows both a detailed and wide field of view on the connections that exist inside the brain. Called magnified analysis of proteome (MAP), it provides the location of individual protein molecules while drawing a connectivity map of neurons on a large scale.
The brain, being extremely dense, does not lend itself to optical microscopy techniques since the wavelength of light is too long to resolve many of the organ’s details. To overcome this, the researchers took an unexpected approach of simply stretching a preserved brain while keeping most of its characteristics intact. This is done by injecting acrylamide polymers inside the brain, turning it into a transparent gel-like object with all the proteins and neuronal connectivity intact. Along this process, the proteins are denatured and fluorescent antibody tags that stick to specific molecules are introduced.
Once the gel has stabilized, the brain can be pulled to stretch it out to many times its original volume. As it’s stretched, the tagged proteins and long distance connections are also pulled apart. Traditional microscopy techniques can be used at this point to visualize the connections and locations of tagged proteins.
Since the spatial relationships don’t change, but only the distances between objects, a computer can be used to calculate where everything was originally before being pulled apart.
Here’s an MIT video describing the magnified analysis of proteome technique:
Study in Nature Biotechnology: Multiplexed and scalable super-resolution imaging of three-dimensional protein localization in size-adjustable tissues…