Figure 1. Odors evoked LFP oscillations in the moth MB and AL.
(A) Recording site for LFP: center of the calyx in the MB. MB, mushroom body; mnsc, medial neurosecretory cells; OL, optic lobe; AL, antennal lobe.
(B) LFP oscillations (black traces) with simultaneously-recorded electroantennogram (EAG, green traces) evoked by different pulse durations of 1% benzyl alcohol, a plant volatile. Black horizontal bars: odor pulses. Color bars: time windows (500 ms) used to calculate the power spectra in [D].
(C) Brief odor pulses evoked fast oscillations; lengthy pulses evoked first fast, then slow oscillations. Normalized, average spectrograms from 18 trials obtained from 6 animals with 3 trials each (see Experimental Procedures). Black horizontal bars above each spectrogram: odor pulses.
(D) Power spectra of oscillatory LFP responses averaged from 22 moths and 8 odors, total of 820 trials. Color brackets: 14 Hz-wide bands used to calculate the total oscillatory powers of fast (red, 30-44 Hz) and slow (blue, 10-24 Hz) oscillations in [E].
(E) Total oscillatory power of fast and slow LFP shifted significantly over lengthy odor pulses. Twenty trials tested for each odor were averaged before pooling, mean±SE. n=41; 2-way ANOVA: fwindow(2)=26.62, P<0.0001 (fast oscillations); fwindow(2)=9.09, P<0.0003 (slow oscillations). Asterisks: significant differences (Tukey-Kramer multiple comparisons).
(F) LFP oscillations in the AL and MB were highly coherent. Left: Example of odor-evoked LFP oscillations recorded simultaneously in the AL and MB; odorant: 1% cyclohexanone (4 s). Areas a and b are expanded in insets. Horizontal red (0.25-1 s) and blue (1-4 s) bars: times used for coherence analysis at right. Right: Magnitude squared coherence between the AL and MB. Thin black line: coherence of the response shown. Thick black and dotted lines: average coherence and its one standard deviation range (5 AL-MB combinations in 4 preparations, 20 trials each of 2 odorants), respectively.