Fig. 2.

PLA₂ and AA are involved in the signaling route activated by the agonists. A, AA and PLA₂ induce an outward current, similar to that induced by dopamine. Bars indicate extracellular applications of AA (5 sec, 50 μm), PLA₂ (20 sec, 122.5 U/ml), and dopamine (1 sec, 1 μm). The cells were voltage clamped at −40 mV. Responses are from different cells. B, C, FMRFa occludes the response to PLA₂. B, Combined application of FMRFa and PLA₂ fails to show summation of the responses to FMRFa and PLA₂. Average amplitudes (right) of the responses to a maximal dose of FMRFa (10 μm) alone and to the subsequently applied combination of FMRFa and PLA₂ (50 U/ml) (n = 4). C, Application of FMRFa during a response to PLA₂ increases the current amplitude up to the level of the response to FMRFa alone. The right panel shows the average current amplitudes to FMRFa alone and to PLA₂ alone compared with the response amplitude obtained when FMRFa was applied during a PLA₂ response (n = 4).