Impact of dental deafferentation on ingestive, aversive and histomorphometric behaviour in Wistar rats

Abstract

Dental deafferentation directly affects taste perception. Although previous studies have addressed this phenomenon, a comprehensive understanding of its neurophysiological mechanisms requires further investigation. Therefore, using a dental deafferentation model induced by molar extraction in Wistar rats, both ingestive and aversive behavioral responses to taste stimuli were evaluated, alongside histomorphometric changes in the circumvallate papillae, with correlations established between these parameters. The study included an experimental group subjected to extraction of the three molars and a control group, each consisting of seven biological replicates. Polyethylene cannulae were implanted in both groups, and behavioral responses were subsequently assessed. The animals were then euthanized, and their tongues excised for histomorphometric analysis, which quantified the number of taste buds, length of the papillary trench, total thickness of the keratinized epithelium, and maximum width of the circumvallate papilla. The main results revealed significant differences between control and experimental groups in behavioral responses, along with a reduction in both the number of taste buds and the papillary trench length. Additionally, significant correlations were identified between behavioral outcomes and histomorphometric alterations. In conclusion, dental deafferentation induced by extraction of the three molars leads to gustatory dysfunction, altering behavioral responses and resulting in structural changes of the circumvallate papilla. These findings underscore the need to deepen the understanding of dental deafferentation effects, paving the way for the development of more effective therapeutic interventions aimed at restoring compromised taste function.