Abstract
Despite the importance of dendritic arbors for proper neuronal function, our knowledge of how sensory experience influences these structures during postnatal cortical development is incomplete. We present a large-scale dataset of 849 three-dimensional reconstructions of pyramidal neuron basal arbors collected across early postnatal development in the mouse visual cortex. We found that the basal arbor underwent a 45% increase in total length between postnatal day 7 (P7) and P30. Surprisingly, comparisons of dark-reared and typically-reared mice revealed that only 15% of arbor length could be attributed to visual experience. Furthermore, we characterized the role of the activity-regulated small GTPase Rem2, showing that Rem2 is an experience-dependent negative regulator of dendritic segment number during the visual critical period. These data establish a detailed, quantitative analysis of the basal arbor that has high utility for understanding circuit development and providing a framework for computationalists wishing to generate anatomically accurate neuronal models.
