Fig. 1.

Beta oscillations are present in all 3 structures. A: sample data (2 s for each panel) from olfactory bulb (OB), anterior pyriform cortex (aPC), and posterior PC (pPC) during odor sampling for coarse/nonanone and fine/octanone odor sampling, vertical line indicates nosepoke which triggers the 1.5 s odor pulse. Top: raw local field potential (LFP); middle: gamma-filtered; bottom: beta-filtered. B: beta oscillations from a go/nogo (GNG) task for comparison, nosepoke is at the beginning of the 2 s sample (unpublished data from D. Frederick and L. M. Kay). Data for both A and B are normalized to the SD of the nonbeta periods surrounding the beta burst region. This allows visual comparison of the relative amplitudes of the beta event across rats and behavioral conditions. C: power spectra for all 3 areas during ketone discrimination (butanone/nonanone and octanone/heptanone). In each plot the black curve refers to odor A (butanone and octanone) and the gray curve to odor B (nonanone and heptanone). 95% confidence limits from the jackknife method are barely discernable about the spectral plots. Spectra are from data normalized by the SD of a preexperiment quiet period, so units are dimensionless. D: nonoverlapping blocks of 10 successive trials (both odors combined) show a fast rise in beta power at the beginning of each session. Data are from 1 session, fine ketone discrimination, but the rise is repeated across subjects and odor sets. The subsequent decrease in beta power in this example is not repeated in all rats and odor sets. The solid line signifies blocks that are elevated relative to the first block. The dashed line indicates blocks that are decreased relative to the blocks 3 and 4.