3D brain *doughnuts* created

Press Association – 

Three-dimensional brain "doughnuts" made from partitioned nerve cells and fibres have been created by scientists.

The doughtnuts could be used to study damage caused by injury and disease, improve understanding of brain function, or aid the development of new treatments - as well as to provide an alternative to distressing tests conducted on animals.

Professor David Kaplan, who led the bioengineers at Tufts University in the US, said: "There are few good options for studying the physiology of the living brain, yet this is perhaps one of the biggest areas of unmet clinical need when you consider the need for new options to understand and treat a wide range of neurological disorders associated with the brain."

Each doughnut "ring" consists of neuron cell bodies, while bundles of connecting axons - the fibres that carry nerve signals - fill the centre. The structures, measuring up to 1.2 centimetres across, mimic the kind of compartmentalisation found in a real brain.

Until now neurons have only been grown in a haphazard, unstructured fashion in the laboratory.

The new approach replicates the complex organisation of real brain tissue, which segregates itself into regions of "grey" and "white" matter. Grey matter consists of nerve cell bodies while white matter is made up of axons.

To make the doughnut, the scientists cut a spongy silk protein scaffold into a ring shape and seeded it with rat neurons. The middle of the doughnut was then filled with a collagen-based gel. In just a few days, the neurons formed functional networks around the pores of the scaffold.

They also sent axon projections through the centre gel to connect with neurons on the opposite side. Eventually a distinct white matter region formed in the centre of the doughnut that was separated from the surrounding grey matter.

Tests showed that the brain-like constructs could be kept alive in the laboratory for more than two months. Experiments that involved dropping weights on to the doughnuts from varying heights demonstrated their potential for studying brain injury.

"With the system we have, you can essentially track the tissue response to traumatic brain injury in real time," said Prof Kaplan. "Most importantly, you can also start to track repair and what happens over longer periods of time."

He added: "The fact that we can maintain this tissue for months in the lab means we can start to look at neurological diseases in ways that you can't otherwise because you need long time-frames to study some of the key brain diseases."

Details of the research appear in the journal Proceedings of the National Academy of Sciences.

https://uk.news.yahoo.com/3d-brain-doughnuts-created-215315203.html