Researchers, led by a team at UT Southwestern Medical Center, have identified the cellular and molecular features of the brain that distinguish modern humans from their closest primate and ancient human ancestors. The survey results are Natureprovides new insights into the evolution of the human brain.
“Most evolutionary research on the human brain has focused on neurons because this cell type was thought to be responsible for our intelligence and enhanced cognitive abilities. , gives us a new understanding of other cells involved in brain function and the roles they have played in both.” Cognitive progress and our susceptibility to many cognitive disorders It’s helping us improve,” said study leader Dr. Genevieve Konopka, professor of neuroscience and member of the Peter O’Donnell Jr. Brain Institute at UT Southwestern University.
Since ancient times, people have been curious about what gives humans abilities that other animals don’t, such as speech and language, Konopka explained. A series of previous studies have explored the anatomy of the brain, performed genetic and molecular studies of the whole brain or parts of it, and conducted experiments that allowed us to observe thousands of cells at once. I have been trying to answer this question.
Dr. Konopka and colleagues theorized that more could be gleaned by looking at the brain’s features at the cellular level, a feat only made possible by recent technological advances. In the study, researchers from the Konopka Lab, including lead author and O’Donnell Brain Institute Neuroscientist Training Program Fellow Emre Kaglayan, BSc, along with colleagues from George Washington University, Emory University, and the University of California, Santa Barbara. , focused on Brodmann’s area 23 (BA23) of the posterior cingulate cortex. BA23 is also part of the default mode network, a complex of interconnected regions that maintain activity when the brain is in a wakeful resting state, and is thought to be involved in schizophrenia.
Rather than examining BA23 in its entirety, the researchers used a relatively new technique called single-nuclear RNA sequencing to examine the cell types that make up this region, comparing samples from humans, chimpanzees, and rhesus monkeys. Ta. They found that, in contrast to nonhuman primates, humans have a much higher proportion of oligodendrocyte progenitor cells (OPCs). OPCs are precursors to a class of cells known to provide neuronal support and insulation, and are increasingly involved in regulating brain circuits. Furthermore, two subtypes of excitatory neurons that share information through electrical impulses showed increased expression in humans of the gene that makes FOXP2, a protein involved in brain development associated with speech and language. Ta.
In another experiment, researchers compared DNA from modern humans to that of ancient human relatives Neanderthals and Denisovans. They looked not only at genetic code differences, but also whether these differences occur in genomic regions where cellular machinery regulates gene expression. Their search identified dozens of genes that differed functionally between humans and their ancient relatives, particularly in the upper layer of excitatory neurons at BA23, providing further insight into the evolution of the human brain in future studies. may be obtained.
Dr Konopka said these findings provide a roadmap for understanding how the human brain developed the unique ability to distinguish humans from other species.
Dr. Konopka is a John Hyten Scholar in Autism Research and serves as the Townsend Distinguished Chair of the Autism Spectrum Disorder Research. Other UTSW researchers who contributed to this work include postdoctoral researcher Yuxiang Liu, Ph.D., graduate student, Rachael Vollmer, Ph.D., and Emily Oh, Ph.D.
For more information:
Emre Caglayan et al., Molecular features driving the cellular complexity of human brain evolution. Nature (2023). DOI: 10.1038/s41586-023-06338-4
Quote: Research Identifies Unique Properties of the Human Brain (08/10/2023), Retrieved 08/11/2023
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