In the 1987 series of off-prints from the Edinburgh Research Station (ERS) – Institute of Animal Production and Genetic Research (IAPGR), I found the interesting article – “Facial nerve sensory responses recorded from the geniculate ganglion of Gallus gallus var. domesticus” by Michael J. Gentle which appeared in the Journal of Comprehensive Physiology, Volume 160, (1987), p. 683-691. In this article he discusses an experiment in which a chicken’s facial nerve response is recorded ‘from the geniculate ganglion … following chemical, mechanical and thermal stimulation of the oral cavity using glass coated tungsten microelectrodes.’ According to Gentle, ‘ [T]he results show that the facial nerve plays the major role in gustatory physiology of the chicken and these results are discussed in relation to the mammalian gustatory system.’
The photograph shows the inside of a chicken’s beak – the anterior palate (AP), the posterior palate (PP), and the anterior mandibular area (AMA).