Figure 9.

Habituation of DCMD is accompanied by habituation of the FETi compound PSP. A, Peak firing frequency in DCMD habituated on repeated stimulation by a looming object of l/|v| = 20 ms at 1 min intervals. The habituation was stronger in solitarious (black) than gregarious (gray) locusts. B, The maximum amplitude of the compound PSP in FETi also decreased on repeated stimulation. In solitarious locusts, the amplitudes diminished within 10 stimuli to nearly the same amplitudes as single PSPs (dark gray band). The light gray band indicates the equivalent amplitudes of single PSPs in gregarious locusts. C, The relationship between peak compound PSP amplitude and peak DCMD firing rate differed between phases. All data are means ± SEM.