Scientists have created the largest mammal neural connectoma so far, with mapping a part of the brain of a mouse the size of a sand grain.
A team of over 150 scientists revealed the more detailed map of a mammal brain to date, drawing a small section of 1 millimeter cubic brain of a rat.
The mapped section is approximately the size of a grain of sand, but is full of astonishing 200 000 cells and more than 523 million synapses. The project, led by the Microns Consortium, was detailed in a series of articles in the journal Nature on April 9.
The intricate map, known as “connectoma”, captures a section of the occipital lobe – the brain region responsible for visual processing. To create it, researchers began by observing the brain activity of a living, genetically modified rat, whose neurons shone when they were active. While the rat saw films such as Mad Max, Matrix and Star War, the investigators recorded the activity of 76,000 neurons.
After that, the brain of the rat was extracted and photographed with an electronic microscope. An automatic learning algorithm then traced the neurons and their branches, resulting in a huge 3D map which distinguishes various types of cells, including neurons and glial cells, explains the.
Jacob Reimer of Baylor College of Medicine observed the surprising complexity of such a small area. “A millimeter looks small, but inside this millimeter miles of wires“, These.
The data set is currently the Largest neural map in the worldsurpassing the previous connects created from human brains and fruit flies. However, work remains incomplete because some cells and brain connections are missing and the data set includes “orphan” extensions – neural branches with unidentified origins. Much of validation work is done manually, although software tools helped automate part of the process.
Among the main conclusions, scientists confirmed that the neurons that trigger together tend to connect to long distances. The map also revealed that inhibitory neurons – which attenuate the activity of other neurons – can form highly specific and long -range bondswhich challenges previous assumptions about their role in local brain circuits.
Scientists expect this map to provide new knowledge about neurological diseases, such as Alzheimer’s disease and multiple sclerosis, where cerebral circuits are damaged.
