Abstract
While it has long been assumed that olfactory input influences taste but not vice versa, recent evidence from our lab reveals that an area of the cortex: known to process tastes is necessary for proper olfaction. The results of this previous study beg the question, however, of whether it is solely the central connections between the olfactory and gustatory systems which affect olfactory processing, or whether gustatory input itself is necessary. Here we show that a short-acting topical anesthetic placed on the tongues of rats did not inhibit acquisition of a food preference in a paradigm that is well established to require only olfactory cues: socially transmitted food preference (STFP). However, a longer lasting injected anesthetic did impair food preference learning. Electrophysiology recordings confinned that both anesthetics did indeed impair lingual sensory function. This work suggests that input from the lingual epithelium may be an important modulator of olfactory processing, although it remains possible that motor, rather than sensory, deficits are responsible for these results; future work will attempt to rule out this alternate explanation. Our data further support the suggestion that chemosensation is a fully multi-modal process and that olfactory processes can no longer be thought of as isolated from gustatory stimuli.