 |
| Revolutionary Discovery: Unveiling the Human Brain's Complexity in the Largest-Ever Atlas |
Researchers have achieved a remarkable milestone by producing the most extensive catalog of human brain cells to date. Their comprehensive atlas unveils over 3,000 distinct cell types, many of which were previously unknown to science. This groundbreaking research, featured in a collection of 21 papers across various scientific journals, promises to significantly impact the study of diseases, cognition, and the essence of human identity.
This colossal cell atlas offers an intricate snapshot of the human brain, the most complex organ in our body. While previous research had mapped the human brain through techniques like magnetic resonance imaging, this atlas is the first of its kind, delving into the entirety of the human brain at the single-cell level, exposing its complex molecular interactions. According to Anthony Hannan, a neuroscientist at the Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, "It's highly significant," and these atlases lay the foundation for a deeper understanding of the human brain.
This research is part of the US National Institutes of Health's Brain Research through Advancing Innovative Neurotechnologies Initiative — Cell Census Network (BICCN), a collaborative effort involving hundreds of scientists. The initiative aims to categorize brain cell types across humans, non-human primates, and mice to enhance our understanding of the cellular mechanisms underlying poorly understood brain disorders. The data from these 21 studies are now accessible on the Neuroscience Multi-omic Archive online repository.
The foundation of this atlas was laid by Kimberly Siletti, a neuroscientist at the University Medical Center Utrecht in the Netherlands, and her team. They sequenced the RNA of over 3 million individual cells from 106 locations encompassing the entire human brain, using tissue samples from three male donors and one motor cortex dissection from a female donor. Their analysis documented 461 broad categories of brain cells, which encompassed more than 3,000 subtypes. The diversity of neurons, the cells responsible for transmitting signals within the brain and nervous system, varied significantly across different brain regions, suggesting distinct functions and developmental histories. Moreover, the distribution of neurons and other cell types differed among each region, with some cell types unique to specific locations.
The brainstem, a relatively underexplored structure connecting the brain to the spinal cord, was found to harbor a particularly high number of neuron types, emphasizing the complexity of this region. Further studies within this research delved into the mechanisms of gene regulation and expression in different cells. Joseph Ecker and his colleagues at the Salk Institute for Biological Studies in California utilized tissue samples from the same three donors to investigate the brain from an epigenetic perspective. Their analysis of chemical markers that activate or deactivate genes in over 500,000 individual cells revealed nearly 200 brain cell types. The same gene in the same type of cell displayed distinct characteristics across various brain regions, illustrating remarkable regional differences.
Understanding the genetic switches that control gene expression in brain cells holds the potential to diagnose brain disorders and develop personalized treatments. Bing Ren and his team at the University of California, San Diego, focused on understanding how over one million brain cells from the three donors accessed and employed genetic information. They uncovered links between specific brain cell types and neuropsychiatric disorders such as bipolar disorder, depression, and schizophrenia. By studying these links, researchers can investigate whether particular genes or defective switches directly contribute to the onset of disease.
The next phase for the BICCN team involves sequencing even more cells from all parts of the brain and working with diverse tissue samples to gain insight into how the human brain varies among populations and age groups. This marks only the beginning of a journey to uncover the intricacies of the human brain.
إرسال تعليق