Feldman, D.E., Brainard, M.S. and Knudsen, E.I.: Newly learned auditory responses mediated by NMDA receptors in the owl inferior colliculus, Science 271:525–528, 1996.

The authors wanted to show that NMDA receptors in the brain of the barn owl mediated the learning of sounds. The test system consisted of 5 owls that were surgically modified to permit addition of agonists and antagonists of NMDA and non-NMDA receptors. On the basis of the pharmacologically-induced changes in brain electrical activity, the authors concluded that the newly learned auditory responses in the owl were probably mediated by NMDA receptors.