Spatial organization of EEGs from olfactory bulb and cortex

This report presents evidence for the concept of 'wave packet' (Freeman 1975) in the olfactory system. EEG bursts recorded from electrodes chronically implanted at multiple sites in the olfactory bulb and cortex in awake rabbits were spatially coherent, iso-frequency events. Both bulbar and cortical bursts were composed of a major oscillation in the 35-85 c/sec range. The dominant cortical frequency was within 5% of that of the bulb. A secondary oscillation in the 15-35 c/sec range was found in both bulb and cortex. This was thought to represent a feedback signal of the cortex to the bulb.