Abstract
Insular cortex is perhaps the most highly integrated yet anatomically compact cortex of the brain. Although the insula’s gross anatomy, cytoarchitecture, and projections have been well documented, little is known about the morphology of insular pyramidal neurons or how they may relate to homologous structures of the neocortex. Previous investigations have found significant variation in dendritic arbors throughout the cerebral cortex1,2. Specifically, supragranular pyramidal cell dendrites are found to increase in complexity across a caudal to rostral gradient2 and in parallel to the ascension of the cortical hierarchy of computational complexity1. This suggests that neurons from different cortical areas vary, not only in the quantity and type of information they process, but in their dendritic composition as well.
Following the caudal to rostral trend found in the cerebral cortex2 we suspected that dendrites in the anterior insula would be more complex than dendrites in the posterior insula. In addition, we suspected that dendritic structures in the insula would utilize a unique architecture in comparison to the evolutionarily younger isocortex of the supero-lateral surface of the cerebrum.