Abstract
Neurons and epithelia are viewed as fundamentally different cell types, yet some sensory neurons exhibit hallmarks of epithelial cells. For example, they use tight junctions to form a diffusion barrier continuous with the skin or other epithelia and they exhibit bona fide apical-basal polarity, with an outward-facing apical surface that is biochemically and functionally distinct from their inward-facing basolateral surface. Yet they are unmistakeably neurons with axon-dendrite polarity. Examples include olfactory receptor neurons and photoreceptors. In this review, I highlight how viewing these neurons as specialized epithelial cells informs our understanding of their development and raises intriguing questions about the establishment of apical-basal and axon-dendrite polarity.