A mammalian taste bud is a collection of approximately 50-100 cells present in the lingual papillae, i.e., fungiform, foliate, and circumvallate papillae, and palatal epithelium. The most important function of taste buds is the detection of taste. Many animals can detect aqueous chemical stimuli immediately after birth, indicating that some taste buds are morphologically and functionally mature at birth. Developmental studies have revealed that the morphological maturation of taste buds in lingual papillae occurs postnatally, while those in the soft palate mature prenatally. Interestingly, some isolated cells in the gustatory epithelium display immunoreactivity for alpha-gustducin, a taste-specific G protein, during the development of taste buds, indicating the existence of another gustatory system during the neonatal stage in mammals.