Scientists map visual neurons from mouse and fruit fly giving fascinating glimpse into the workings of the brain (video)

Scientists have taken a major leap in unravelling the mysteries of the human brain after developing a new technique with which they were successfully able to map visual networks from a mouse and a fruit fly, the Daily Mail reported.

Professors from the Max Planck Institute of Neurobiology in Martinsried, Germany and the Howard Hughes Medical Institute in Ashburn, Virginia, collaborated with teams of students to create three-dimensional maps of tiny sections of the animals' retinas.

It is hoped that the techniques devised for the studies could soon be used to create a detailed map of the far more complicated human brain.

For the mouse study, the brain-tissue was sliced thinly before being scanned using an electron microscope, according to nature.com.

A computer was used to build a basic model, assigning different colours to different structures and identifying the points where individual cells meet known as the synapses.

But the computer was unable to complete the complex task of joining the coloured sections together to create a complete map of the individual pathways.

So a team of 300 students spent approximately 30,000 hours painstakingly tracing the branches of each cell to build an accurate model.

The study identifed a new type of cell known as an XBC cell which was found to relay visual information from photo receptors to other cells.

Despite the vast amount of labour involved, the model they created represents just 0.06 per cent of the mouse retina.

In the case of the much smaller fruit-fly brain, two separate studies were conducted aimed at understanding how it detects
movement.

One group mapped the neurons of the fly's motion-detector circuits. They discovered each was wired to detect motion in a particular direction.

A second group examined the same motion-detector circuits but looked into how the cells reacted to stimulation with light.

Because the photo-receptor cells on the surface of the eye can't detect motion themselves, the group concentrated on two downstreaming processing neurons named T4 and T5.

By tagging the cells with fluorescent protein markers which glow when a neuron is active they were able to show how different groups of neurons respond to the four basic motions - either up, down, left or right.

Because a human brain contains roughly 80billion neurons it would take an estimated 570,000,000 years to map.

However the researchers hope that by improving the technique used in the studies can be improved and with the aid of more powerful computers it will one day be possible.