Indian and International Researchers prepare Human Brain Charts spanning entire Lifespan

Bengaluru: Recently, a series of brain charts documenting the entire human lifespan from a 15-week-old-fetus to a 100-year-old-adult showing how human brains expand rapidly in early life and steadily shrink as people age has been published online. The study was conducted by a team of international as well as Indian researchers from across six continents.

The Indian researchers who are part of the project and contributed to the Indian dataset are from the Consortium on Vulnerability to Externalising Disorders and Addictions [cVEDA] led by scientists from the National Institute of Mental Health and Neurosciences (NIMHANS), Dr Bharath Holla from the Department of Integrative Medicine and Vivek Benegal from the Department of Psychiatry, Nimhans. 

Dr Holla and Prof. Benegal told TNEI, "The study authored by Richard Bethlehem from the Department of Psychiatry at the University of Cambridge and Jakob Seidlitz from the Lifespan Brain Institute at Children's Hospital of Philadelphia and University of Pennsylvania, published in 'Nature' online on April 6 is the result of a research project bringing together almost 1,25,000 brain scans from over a 100 different studies, possibly the largest ever MRI datasets ever aggregated."

Nature is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, Nature features peer-reviewed research from a variety of academic disciplines, mainly in science and technology.

Prof. Benegal told The Hindu that "one of the major aims of the cVEDA is to develop brain charts of Indian children growing up so as to create a normative model for mapping individual differences at the level of a single subject. This can be used as a biomarker to predict risk of various neurological and psychiatric illnesses (to enable pre-emptive and early treatment), or track the prognosis and response to treatments."

"For over 200 years, growth charts have been a cornerstone of paediatric healthcare and are commonly used in clinics. They are used to monitor the growth and development of children in comparison to their peers. A typical growth chart plots age on the horizontal axis versus height on the vertical axis, but rather than being a single line showing the average growth, it will show a range that reflects the natural variability in height, weight or head circumference. Significant deviations from the normal range usually predict problems in the child's growth and maturation and are predictive of future health problems," he said.

"There are no similar reference charts for measuring age-related changes in the human brain. The lack of standardized tools and assessments of brain development and aging is particularly relevant to the study of psychiatric disorders. While research in neuroscience and psychiatry has discovered significant differences in brain structure, function, and psychological functioning between people with and without mental illnesses, there are still at the level of differences between groups of people with and without the illness. The data in neuroscience has not translated into individual care and does not account for wide variations seen in the real world. This study is a major step towards filling this gap," he explained.

He further explained, "The cVEDA study, which provided a large number of brain scans of youngsters and young adults from India, to this effort, is one of the larger international neuro-developmental cohort studies, of over 9,000 youngsters from seven sites all over India."

"Set up through a Newton-Bhabha grant, funded by the Indian Council of Medical Research and the Medical Research Council, UK, the cVEDA follows these young people through their childhood, adolescence, and young adulthood to understand how their inherited genetic programming is moderated by their exposures to environmental risks through the lifetime to shape their brain maturation and their psychological abilities," he added.

Researchers have used the brain charts to confirm and in some cases, demonstrate for the first time developmental milestones that were previously only hypothesized, such as at what age brain tissue classes reach peak volume and when specific brain regions mature. "We hope the charts will become a routine clinical tool similar to how standardized paediatric growth charts are used," he said.

"Another measure of prediction and tracking that we are studying is an estimate of brain age. This is an index for quantifying individuals' brain health as deviation from a normative brain aging trajectory. Higher or lower-than-expected brain age is thought to reflect different from average rate of brain aging, and is increasingly understood to be associated with mental illness," he said.