A brief survey of the modifications in sensory-secretory organs of the neonatal rat tongue

Recent data obtained on rats suggest that in the days immediately following birth several events take place in the circumvallate papillae of the oral cavity. A phylogenetically primitive system of solitary chemosensory cells develops and is rapidly replaced by taste buds. The lipase-secreting von Eb ner gland, which is associated with taste organs, begins to develop by form ing short tubules, The intrinsic nervous system of the gustatory organs rap idly completes its maturation showing fast proliferation of fibers and immu nocytochemical maturation. Intraepithelial lipid accumulation is visible in the non-receptorial mucosa of the tongue, showing aspects which suggest an active lipid secretion. These data demonstrate that in the rat the structu re of the sensory-secretory organs of the newborn's tongue shows a typical conformation with respect to the adult and rapidly changes its organization in the first week after the birth. At the present level of knowledge, it i s difficult to link the anatomical structures to peculiar functional roles but the rather simple organization of the neonatal gustatory epithelium cou ld be in relation to the dietary regimen. The data obtained in laboratory a nimals underline the necessity of studies on human newborns to update the a natomical knowledge of the oral chemoceptive system. Copyright (C) 2001 S. Karger AG, Basel.