P-27 The effect of dual-frequency calls in the phonotactic and neuronal responses in female cricket Acheta domesticus

Female Acheta domesticus respond selectively to model calling songs with intensities above 75 dB and a carrier frequency of 4 – 5 kHz. When the animal is exposed to calling songs with varying syllable periods (30 to 90 ms), it is more likely to perform phonotaxis to calls with syllable periods that approach the most attractive range (50 – 70 ms), hence demonstrating its selectivity. On the contrary, it is less likely to respond phonotactically to calling songs with syllable periods that deviate from the most attractive range. Higher frequency sounds (16 kHz), have been reported to produce an aversive effect on this females, reducing its likelihood of responding phonotactically to such calls. We hypothesized that an attractive call can become unattractive by adding a 16 kHz component to an already existing 5 kHz call. In this experiment, young females (5 – 7 days) were behaviorally tested to 5 kHz, 85 dB calls, followed by a 16 kHz call added in at 65 dB to the existing call. The intensity of the 5 kHz component remained unchanged, while the intensity of the 16 kHz component varied. Preliminary results suggest presenting a combined stimulus can lead to negative phonotaxis. Similarly, the L3 auditory interneuron in response to attractive calls exhibits higher levels of decrement, and responds with less decrement to unattractive calls. We hypothesized that presenting a dual-frequency call will change the decrement levels in the response of the L3. Preliminary results suggest a reduction in L3’s decrement can occur in response to a dual-frequency call.