Bilateral enucleation alters gene expression and intraneocortical connections in the mouse

Our results demonstrate short-term plasticity on postnatal day 10 resulting from the removal of the eyes at birth, with changes in nuclear size and gene expression within the lateral geniculate nucleus as well as a shift in intraneocortical connections and ephrin A5 expression at the somatosensory-visual boundary. In this report, we highlight the correlation between positional shifts in ephrin A5 expression and improper refinement of intraneocortical connections observed at the somatosensory-visual boundary in enucleates on postnatal day 10.Bilateral enucleation induces a positional shift of both ephrin A5 expression and intraneocortical projections at the somatosensory-visual border in only 10 days. These changes occur prior to natural eye opening, suggesting a possible role of spontaneous retinal activity in area border formation within the neocortex. Through these analyses, we gain a deeper understanding of how extrinsic activity-dependent mechanisms, particularly input from sensory organs, are integrated with intrinsic activity-independent mechanisms to regulate neocortical arealization and plasticity.All mammalian behavior is generated and regulated by the nervous system. In humans, the neocortex is the structure within the nervous system that is responsible for the complex integration of information, the ability to utilize language, decision-making, motivation and other high-level emotive-cognitive processes. The complexity of the neocortex emerges during development through arealization, when specific sensory and motor functional units, or areas, are formed and connected to one another and to sub-cortical nuclei through a vast and complex network of intra- and extra-neocortical connections.Research on the developmental mechanisms that drive arealization has been influenced by two alternative hypotheses. Rakic [1] famously detailed his protomap hypothesis, suggesting that the fates of different neocortical regions were pre-specified in early development, by ye