Mapping the distribution of neuroepithelial bodies of the rat lung. A whole-mount immunohistochemical approach.

We report an immunohistochemical method for mapping the distribution of neuroepithelial bodies (NEBs) in whole-mount preparations of the intrapulmonary airways. The lungs of 8- and 50-day-old male Sprague-Dawley rats were fixed with ethanol-acetic acid by intratracheal instillation. The major axial airway path of the infracardiac lobe was exposed and isolated by microdissection. NEBs were identified by calcitonin gene-related peptide immunoreactivity and their distribution mapped by generation and branch-point number. A distinct pattern was noted with greater prevalence of NEBs in proximal airway generations compared with more distal airways. No significant difference was noted in the distribution pattern or absolute number of NEBs between neonates and adults when compared by airway generation. NEBs were found more frequently on the ridges of the bifurcation than in other regions of the bifurcating airway wall. The ease of identification of total numbers of NEBs and their specific location by airway generation in whole-mount preparations of the bronchial tree completely removes the necessity of examining multiple sections and performing extensive morphometric procedures. Whole-mount airway preparations allow for the analysis and comparison of larger sample sizes per experimental group without labor-intensive approaches. The application of this method should enhance our knowledge of the role of NEBs in lung development and in response to disease.