Open AccessEffects of 12 days of artificial rearing on morphology of hypoglossal motoneurons innervating tongue retrusors in rat
Author(s) -
Smith J. Chadwick,
Mcclung J. Ross,
Goldberg Stephen J.
Publication year - 2006
Publication title -
the anatomical record part a: discoveries in molecular, cellular, and evolutionary biology
Language(s) - English
Resource type - Journals
eISSN - 1552-4892
pISSN - 1552-4884
DOI - 10.1002/ar.a.20277
Subject(s) - tongue , biology , anatomy , horseradish peroxidase , cholera toxin , hypoglossal nerve , morphology (biology) , endocrinology , medicine , pathology , biochemistry , zoology , enzyme
The purpose of this study was to examine the influence of reduced tongue activity by artificial rearing on the morphology of motoneurons innervating the extrinsic tongue retrusors. Artificially reared rat pups were fed via gastric cannula from postnatal day 3 to postnatal day 14. Artificially reared animals and dam‐reared controls had cholera toxin (subunit B) conjugate of horseradish peroxidase injected into the styloglossus to label motoneurons innervating hyoglossus and styloglossus on postnatal day 13 and postnatal day 59. Following perfusion on postnatal days 14 and 60, serial transverse sections treated with tetramethyl benzidine and counterstained neutral red were used to analyze motoneuron morphology. The shorter diameter of hyoglossus motoneurons increased with age for the dam‐reared but not the artificially reared group. There was a tendency for a similar pattern for styloglossus motoneurons across the two rearing groups. The changes in form factor reflected the changes in shorter diameter for both motoneuron pools. Therefore, reducing suckling activity during normal postnatal development leads to diminished motoneuron somal growth in rats. This may also be the case in premature infants necessarily fed artificially. © 2005 Wiley‐Liss, Inc.