Fig 5. Mapping of inhibitory regions.

(A) Spikes associated with each random block of stimulation were averaged across the stimulation space on the dorsal glomerular layer. Respiratory activity was not subtracted. Activity in the heat map was thresholded at 5 Hz to highlight regions of little activity in response to random block stimulation. Sites of inhibition were isolated (ROI 1 and 2) as regions of black where low MTC activity was observed when light stimulation excited those glomerular areas. Black scale bar is set to 1 mm. (B) Random blocks of stimulation hitting the two selected regions of interest (ROI). White scale bar is set to 1 mm. Data from single unit recordings in response to optical stimulation of glomeruli in ROI 1 (C,D) and ROI 2 (E,F). (C,E) Peristimulus histograms of the average responses to stimulating ROI 1 (104 stimulations) and ROI 2 (211 stimulations). Stimulus onset times are aligned at time 0s. Stimulations presented during all phases of the respiratory cycle are displayed. Stimulated ± SE (red) and control ± SE (grey) polar plots showing spike rates (radii) post stimulation (red) and no stimulation (black) at (D) ROI 1 and (F) ROI 2. ROI 1 was stimulated 104 times (13, 19, 24, 22, 8, 18 per 1/6^th cycle angle range) and had 1168–1230 control measurements per 1/6^th cycle angle range. ROI 2 was stimulated 220 times (42, 36, 39, 31, 30, 42 per 1/6^th cycle angle range) and had 1168–1230 control measurements per 1/6^th cycle angle range. *: P < 0.05.