The human brain, in particular the cerebral cortex, has undergone rapid expansion and increased complexity during recent evolution.
One striking feature of human corticogenesis is that it is highly protracted in time, from prenatal stages of neurogenesis (taking months, instead of days in the mouse), to postnatal stages of neuronal maturation and circuit formation (taking years, instead of weeks in the mouse). This prolonged neural development, or brain neoteny, is thought to contribute in an important fashion to human brain specialized functions, through enhanced circuit complexity and plasticity.
In vitro and xenotransplantation models indicate that the developmental timing of corticogenesis is largely intrinsic to cortical progenitors and neurons. The underlying mechanisms include divergence in the underlying gene regulatory networks, but also species-specific cell properties such as mitochondria dynamics and metabolism.
Newly discovered human-specific modifiers of cortical neuron development and function shed light on human brain evolution, and provide unexpected links to brain diseases, to which our species is particularly sensitive.