Behavioral discrimination between glutamate and the four basic taste substances in mice.

1. Behavioural studies using the conditioned taste aversion (CTA) paradigm in mice showed that aversion conditioned to monosodium L-glutamate (MSG), which elicits a unique taste in humans, did not strongly generalize to any of the four basic taste stimuli, suggesting that mice could behaviourally discriminate between MSG and the four basic taste stimuli. 2. Denervation of bilateral glossopharyngeal nerve significantly increased behavioural similarities (the strength of generalization in the CTA paradigm) between MSG and sodium salts. This was not the case after destruction of the bilateral chorda tympani nerve. 3. These results suggest that taste information of glossopharyngeal nerve plays a more important role in the behavioural discrimination between MSG and the four basic tastes than does that of the chorda tympani nerve.