Fig. 6. A greater response in the rhinophore nerve to prey odour than to control. (A) Extracellular activity was greatest in response to perfusion of prey odour through the sensory tuft, with a lesser increase over baseline in response to control seawater. Bar indicates odour stimulus duration. Scale: 10 µV between < and marks. (B) Raster plots of extracellular spikes surpassing +10 but not +20 µV (< and , respectively, in A) for all five trials on this rhinophore (+,x,o indicate the raster plots for the recordings in A). (C) Mean spike counts with standard error bars from all five trials, grouped into ten intervals. This rhinophore responded more strongly, on average, to seawater with prey odours than control seawater. Time for B and C is measured relative to the perfusion stream switch for prey and control applications, and an arbitrary time between trials for baseline. Broken lines show the time window used for spike count analysis.