Taste bud distribution and innervation on the palate of the rat

• Published in: Chemical senses 1982, Vol.7 (1), p.99-108
• Main Authors: Miller, Inglis J., Spangler, Kevin M.
• Format: Article
• Language: English
• ISSN: 0379-864X; 1464-3553
• DOI: 10.1093/chemse/7.1.99

The functional properties of taste buds on the palate have not been investigated in laboratory mammals due to limited information about their spatial distribution and innervation. Three regions of the rat's palate contain a mean total of 227 taste buds. The nasoincisor ducts (NID) are located on the incisal papilla at the first antemolar ruga and contain a mean of 66 taste buds (29% of total) divided between the two ducts. About four taste buds (1.8% of total) on the NID survive bilateral transection of the greater superficial petrosal nerve (GSP). At the boundary between the hard and soft palate is a narrow strip of taste buds termed the ‘Geschmacksstreifen’ (GS). This bilateral structure contains a mean of 69 taste buds (30% of total), all of which degenerate with transection of the GSP. The posterior palatine field (PPF) of the soft palate contains a mean of 92 taste buds (41% of total) clustered along the midline from the GS to the nasopharynx. A mean of 29.9 (13.2% of total) taste buds on the PPF survive GSP transection. The distribution of the GSP from both sides overlaps bilaterally to a high degree. It is concluded that 85% of the palatal taste buds in the rat are innervated by the GSP division of the facial nerve, while the remaining 15% are probably innervated by glossopharyngeal fibers which reach the palate by way of the pterygopalatine artery.