Mitral cell single responses in the olfactory bulb of the rabbit to different intensities of olfactory stimulation

Neural spike activity was recorded from 50 single mitral cells in the Rabbit olfactory bulb, with variable intensity of the odour stimulation. Six different concentrations were used for two olfactory stimuli, isoamyl acetate and propanol. The discharge frequency of 40 p. 100 of the cells remained constant regardless of the stimulus concentration; most of these cells (80%) showed inhibitory responses. On the other hand, most of the excitatory responses varied depending on stimulus concentration; the frequency vs stimulus concentration function either increased (25% of cells) or decreased (17%), or displayed a maximum (12%).