With promising drugs falling at the final hurdles and its causes still the source of huge mystery, there is a lot to learn about Alzheimer's and how it can be better treated. Scientists now have an inventive new tool with which to look into such matters, in the form of a transparent skull that allows them to peer into the heads of mice to see how the disease or brain injuries can affect various parts of brain.

Scientists at the University of Minnesota created the device, which they've dubbed the See-Shell, by tapping into the remarkable capabilities of 3D printing. Over the last few years we've seen how this technology can be used to create all kinds of customized medical implants, ranging from bespoke rib cages for humans to 3D-printed beaks for injured turtles.

The U of M researchers crafted the device by digitally scanning the surface of the mouse skull and then creating an artificial replica, but in transparent form. The top of the mouse's real skull was then carefully removed through surgery and and replaced with the see-through implant, enabling the researchers to record brain activity and image the entire organ in real time.

Part of the motivation of this research is to try and gain a clearer picture of how activity in one part of brain can impact an entirely different one. Previously, scientists would home in on particular regions of the brain to try and figure out what makes them tick, but this tool may now open some interesting new doors.

"What we are trying to do is to see if we can visualize and interact with large parts of the mouse brain surface, called the cortex, over long periods of time," says Suhasa Kodandaramaiah, a co-author of the study. "This will give us new information about how the human brain works. This technology allows us to see most of the cortex in action with unprecedented control and precision while stimulating certain parts of the brain."

In one of their first experiments, the team used the See-Shell to study how mild concussions to one part of the brain can influence entirely different ones as the brain reorganizes itself both structurally and functionally. In another experiment, video captured using the device revealed changes in brightness in response to heightened neural activity, with subtle flashes appearing when the whole brain fired up at once.

What's particularly promising about all this is that, according to the researchers, mouse brains have a lot of similarities to human brains. Meaning that this could prove an invaluable tool in studying degenerative brain diseases like Alzheimer's or Parkinson's, or simply the effects of aging. Importantly, the implant wasn't rejected by the mouse's immune system, allowing for long-term observations of the brain.

"These are studies we couldn't do in humans, but they are extremely important in our understanding of how the brain works so we can improve treatments for people who experience brain injuries or diseases," says Timothy J. Ebner.

The short video below shows changes in brightness in response to neural activity in mouse brains via the See-Shell, while the team has also published a paper describing the research in Nature Communications.