Impact of Jacobson's (Tympanic) Nerve Sectioning on Middle Ear Functions

Abstract

The purpose of this study was to evaluate the influence of sectioning of the Jacobson's (tympanic) nerve on middle ear functions. Twenty-five adult New Zealand rabbits were included in this study. The Jacobson's nerve was cut in the left ear of the rabbits (study group), whereas only a small mucosal incision was performed while keeping the Jacobson's nerve intact in their right ear (control group). After the operation, the ears were assessed both otomicroscopically and histopathologically on Days 30, 60, and 90. On otomicroscopy, retraction pockets were observed in 48 and 4% of the ears in the study and control groups, respectively (p < 0.001). Middle ear effusion was observed in 56 and 12%, respectively (p < 0.01). Histopathologically, an inflammation in the middle ear mucosa was present in all ears in the study group, whereas it was present only in 20% of the control ears (p < 0.001). Goblet cells were observed in 48 and 20% in the study and control groups, respectively (p < 0.04). In the study group, the otomicroscopic and histopathologic findings were more prominent on Day 60 compared to Day 90 (p < 0.05). Tympanic glomus cells seem to act as middle ear chemosensory organs and are involved in the regulation of middle ear aeration. Disruption of these neural elements such as Jacobson's nerve negatively impacts on middle ear functions and may result in atelectasis.