Fig. 12.

Directional sensitivity of DMIs. Directionality is plotted as average number of impulses recorded for taps delivered from each of the four directions tested: front (Front), back (Back), medial (Med), lateral (Lat). Front and back represent stimuli moving the flagellum parallel to the long axis of the body, as shown in theinset; medial and lateral were movements at right angles to those shown. Taps were delivered to deflect the antenna by the same amplitude (1.0 mm) and at the same rate (0.1 mm/msec) on all trials. These values were chosen because they were optimal for activating the cells. Means for each direction (black squares) were derived by averaging responses for each animal and then calculating the grand mean across animals ± SEM. Top, Response of DMIa-1 to mechanical stimulation of the contralateral antenna. Data from 11 cells, each from a different animal. Total number of trials = 277. Bottom, Response of DMIb-1 to mechanical stimulation of each antenna. Data from eight cells, each from a different animal. Total number of trials = 329. Left side shows responsiveness of cell to tapping the contralateral (Contra) antenna. Right side shows responsiveness to tapping the ipsilateral (Ipsi) antenna.