Spatial distribution and morphometric characterization of vagal afferents (specifically: intraganglionic laminar endings (IGLEs)) associated with the myenteric plexus of the rat stomach.
As part of the SPARC project, we are interested in understanding the correlations and causative relations between anatomical and functional characteristics of the stomach. IGLE afferents are one of the three types of vagal afferent innervation that are associated with the stomach. To characterize IGLE afferents better, rats were given injections of dextran biotin in the nodose ganglia, and, after tracer transport, stomach whole mounts were collected. Specimens were processed for avidin-biotin permanent labeling, and neurites were then digitized for morphometry and mapping using Neurolucida neural tracing software. This dataset (to date) consists of 124 XML files (~1MB to ~6 MB each) corresponding to IGLE afferents traced from Sprague-Dawley young adult male rat stomachs. Each tracing was analyzed in Neurolucida Explorer to define key neurite metrics such as the area of innervation, average branch length, etc. In addition, the location of the first branch point for each arbor was measured and used to construct a map of IGLE afferent locations across the stomach. In parallel activities, we are assessing the potential correlation between IGLE afferent spatial distributions and the efficacy of stimulation locations for inducing gastric motility. In addition to the digitized tracing files, the dataset also includes: (1) an Excel spreadsheet containing morphometric data, (2) a set of whole mount photographs (jpg) used to register individual stomach contours to a standard stomach contour for generation of the 2D map; (3) a folder of 16 PNG images together with an HTML file that will display an interactive 2D map of neurite locations based on the associated PNG files.