Abstract: | Extracellular recordings were performed from olfactory bulbneurons in the frog. The odour stimuli were the same as thosepreviously used for studying the receptor cells in the sameanimal species and were delivered at similar concentrations(Revial et al., 1982). The general properties of the neuronresponses are presented and discussed with reference to homologousproperties of olfactory receptor cells. The response rates elicitedby different stimuli from the bulbar neurons were found to behighly correlated with those elicited from receptor cells. Theindividual cell selectivity was better in the bulb than in theolfactory epithelium. The olfactory bulb neurons seemed to improvethe discrimination between stimuli (enantiomers) poorly distinguishedby the receptor cells. Reducing odor concentration caused therate of suppressive response to decrease faster than that ofexcitatory ones, suggesting that the manifestations of inhibitoryprocesses in some neurons requires a high level of excitationin others. |