Corpuscular bodies in the palate of the rat. 1. Morphology and distribution.
The morphology and the frequency distribution of corpuscular bodies in the palate was studied in rats using light and electron microscopy. The study extended from the day of birth through 180 days after birth. The corpuscles appeared as round (diameter 35-50 microns) to ovoid (width 40-60 microns, height 60-90 microns) bodies intercalated within the epithelium of the incisal papilla and the soft palate. A subepithelial nerve plexus surrounded the base of a corpuscle. For types of cells were identified within the corpuscle: basal, type I (dark), type II (pale) and type III cells. Some cells bore microvilli which protruded through a pore into the oral cavity. Numerous nerve endings terminated in close relation to the latter three types of cells. Two distinct types of membrane specializations were found representing axosomatic and axo-axonal contacts. On morphological grounds we interpret the structures described as receptors of taste. At birth, a mean total of 21 corpuscles was observed in the entire palate of which 31% was located on the incisal papilla and 68% was found in the soft palate. During the first 2 weeks (16 days) of postnatal life, the number of corpuscles increased. Thereafter, a significant decrease in corpuscle number occurred with increasing age. We speculate that the corpuscles are associated with the learning process of food selection.
Liem
R S
RS
Department of Neurobiology and Oral Physiology, Medical and Dental School, University of Groningen, The Netherlands.
van Willigen
J D
JD
Copray
J C
JC
Ter Horst
G J
GJ
D000375:Aging / Q000502:physiology; D000818:Animals; D008854:Microscopy, Electron; D009412:Nerve Fibers / Q000648:ultrastructure; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure; D010159:Palate / Q000166:cytology / Q000648:ultrastructure*; D051381:Rats / Q000033:anatomy & histology*; D011919:Rats, Inbred Strains