The human brain has largely expanded throughout evolution, and this is linked to an increased intelligence and cognition. In comparison to other mammals, humans have the ability to generate a greater number of neurons during brain development, as a result of changes in neural progenitors’ activity. In humans, these cells show an increased and prolonged proliferation that allow to maximise the number of cell divisions which, ultimately, will result in a higher number of neurons. Disruptions in the proliferative ability of neural progenitors, mainly due to genetic mutations, can lead to abnormal brain development and impaired brain functions. Therefore, unravelling the basic mechanisms driving neural progenitor expansion in humans will contribute to understand the developing brain in health and disease. Previous research has identified human-specific genes that are expressed in neural progenitors and are associated with the expansion of the brain. In this project, we proposed a parallel approach to focus on a gene already known for its role in the mouse brain, MYCN, which also appears mutated in patients with brain disorders. We aimed to study MYCN function by eliminating it from stem cells and assessing the effect of its loss in neural progenitor’s ability to expand and to form neurons. In conclusion, this project identified a novel function of MYCN in human neural progenitors, providing new insights towards the understanding of the developing cortex and its greater expansion in humans.
