obutyric acid-A system may be controlled by the activity of the closely appositioned glutamatergic part, perhaps triggering increased gamma-aminobutyric acid release by Ca2+ influx through glutamate-gated receptor channels ([38]; see also [39]). Given that neuronal circuits underlying odor discrimination, as well as olfactory memory, rely on properties of fast excitatory neurotransmission mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptors (AMPARs), we sought to alter, by genetic means, the specific functional contribution of α-amino-3-hy