Researchers from Washington University’s School of Medicine have developed a new brain map that adds 97 additional regions to the already-known 83.
The research team managed to create the map thanks to MRI data obtained through the Human Connectome Project. 210 subjects were submitted to brain scans, and the resulting program was tested on 210 different subjects. The rendered map was correct 96.6 percent of the time.
The study, published in the journal Nature, shows that brain structure is much more complex than it was initially thought, as there are many areas of the organ whose function remains unknown for the scientific world.
Mapping the brain once more
The study highlights that, to study brain structure, it is necessary to create a map of its cortical areas. The field that the researchers charted were outlined based on their function and connectivity to other regions.
The first 83 areas of the brain were found mainly by post-mortem microscopy, while the newer 97 were found thanks to the Human Connectome Project (HCP). The HCP has the objective of mapping the human brain by analyzing neural pathways that link behavior and brain function. The researchers compare the process to analyzing the fingerprints of each cortical area.
The discovery of the 97 new regions will allow for a much higher precision concerning analyses and studies that allocate stimuli, responses, excretion, and anything that the brain is capable of from within the brain’s structure.
A breakthrough in neuroscience
German neurologist Korbinian Brodmann performed the first mapping of the human brain. He published his charts of cortical areas of humans and monkeys back in 1909. Brodmann conducted thin slices and identified each region of the organ, counting 43.
On the latest study, the process was carried out by a computer which was taught to compare similarities in brain structures and to link each region. The resulting algorithm was very efficient, as it was even possible to discover that some areas were split in two in some patients while in others it was whole, such as in the case of a small area involved with language.
Lead researcher Matthew F. Glasser called the current map obtained thanks to the HCP as a “version 1.0.” He believes that there is a 2.0 version that has much more reliable and specific data. There is no doubt on his part that the brain map will keep evolving with time.
Even if there are dozens of newly-found regions in the brain, the function of each must be researched separately to delve further into the subdivisions within brain structure. The study highlights the fact that DNA correlations must take place to find out which changes in structure are due to genetic traits.
“If you crawl along the cortical surface, at some point you are going to get to a location where the properties start changing, and where multiple independent properties change in the same place,” Glasser commented regarding the process of mapping the cerebral cortex.
The objective of the study was to obtain a reliable brain template, but researchers discovered that is much more to study in the brain’s structure, as there are cortical areas that may highlight a person’s talents and creative abilities, alongside the small but important things that separate humans from each other.
The fruits of the Human Connectome Project
The Human Connectome Project was launched in July 2009, and it is sponsored by the National Institutes of Health. It has the goal of creating a network map or a connectome of the human brain, offering a much broader field of work for the understanding of brain diseases, such as Alzheimer’s, schizophrenia and autism.
The HCP measured the flow of blood when the brain was presented with huge magnets, then, the participant would watch different patterns of lights or perform movements with its hands.
It was discovered that blood flow might serve as an indicator of neuron activity since there was a significant amount of oxygenated blood flowing towards the active brain regions. This method known as functional resonance imaging (fMRI), differs from electroencephalography (EEG), which measures activity in the surface of the skull, and positron emission tomography (PET), which requires the injection of radioactive compounds in the bloodstream.
Co-author of the study Dr. Emma Robinson from the Imperial College of London stated to BBC News that the project is “the culmination of the entire HCP project that we’ve been working towards.” She pointed out that it was a colossal task to label each brain region manually and collaborate to portray an understandable and updated map of the brain.
Each brain that the team had to analyze was different, as the groups of nerve fibers change depending on the subject while they maintained an underlying structure, which was what the computer imaging process had to capture.
The study was praised by Professor Tim Behrens from the University of Oxford. He had worked on HCP but named the new brain map as “awe-inspiring” due to its precision compared to previous efforts. Other scientists refrained from calling the discovered areas ‘new,’ as they were already part of charted sections of the brain, so in theory, every part of the brain had already been discovered. This new brain map will provide neuroscientists with a much more powerful resource carry out studies about the brain divisions based on function.