Fig. 2. Responses (action potentials) of a generalist neurone (number 92) to several compounds, indicating degrees of response and the various delays after the application of stimuli. Compounds are given in the order of their application. TMTDT is (E,E)-4,8,12- trimethyl-1,3,7,11-tridecatetraene. The thick horizontal bar indicates the time at which the compound was applied. 0, no response; +, a weak response; ++, an intermediate response; +++, a strong response (see Materials and methods for details).