Scientists discover a new mechanism that controls brain size

Under the leadership of Professor Lars Allan Larsen and Professor Søren Tvorup Christensen of the University of Copenhagen (UCPH), Denmark, an international research team has taken an important step forward in understanding the complex mechanisms that control the development of the so-called cerebral cortex. which is the part of the brain that plays a key role in attention, perception, awareness, thinking, memory, language and consciousness. The results have just been published in the internationally recognized journal Nature Communications.

Scientists began with genetic analyzes of a large family in which children were born with primary microcephaly; a rare congenital brain disease characterized by a reduction in the size of the cerebral cortex and a varying degree of cognitive dysfunction. Scientists found that the children carried a mutation in both copies of the gene, RRP7A, and by using stem cell cultures and zebrafish as a model organism, RRP7A was shown to play a key role in cell proliferation. stem cells and form new neurons. This process is extremely complex, and minor disturbances can have serious consequences, which may explain why the mutation affects the brain and no other tissues and organs.

“Our discovery is surprising, because it reveals hitherto unknown mechanisms involved in brain development. It also highlights the value of rare disease research, important for both patients and families affected by the disease, but also beneficial to societies below. form of new knowledge about human biology, “says Lars Allan Larsen, Department of Cellular and Molecular Medicine.

The researchers also found that the mutation in RRP7A affects the function of so-called primary cilia, which project in a single copy as antenna-like structures onto the surface of cells to record environmental signals and control the formation of new neurons in brain development.

“Our findings open a new avenue for understanding how primary cilia control developmental processes and how certain mutations in these antenna-like structures impair tissue and organ formation during development. To this end, we have already initiated a series of investigations to understand the mechanisms by which RRP7A regulates ciliary signaling to control the formation and organization of neurons in the brain and how defects in this signaling can lead to brain malformations and cognitive impairments, “says Søren Tvorup Christensen of the Department of Biology.