Bronchiolar neuro‐epithelial bodies in the neonatal mouse lungs

Bronchiolar neuro‐epithelial bodies in neonatal mice were studied by light and electron microscopy. These bodies occurred in thickened areas of the epithelium, and consisted of groups of specialized, non‐ciliated columnar epithelial cells with many cytoplasmic granules. These cells were usually closely parallel to one another and had elongated nuclei containing conspicuous peripheral chromatin condensations. These cells were associated with intra‐epithelial axons. With electron microscopy, the non‐myelinated axon under the neuro‐epithelial body was observed to penetrate the basal lamina and enter the epithelial layer. After penetration, the intra‐epithelial axon containing numerous mitochondria lost its Schwann cell sheath, became enlarged, and ramified among the epithelial cells. These innervated neuro‐epithelial bodies probably function as sensory receptors in the bronchioles.