P-25 Male exposure reduces the response of female crickets (Gryllus bimaculatus) to the male’s calling song: The roles of two auditory neurons

We have evaluated female phonotaxis (walk toward males’ calls) using virgin and male-exposed (raised in the same container) females. While nearly 100% of virgin females respond phonotactically, about 40% of male-exposed females do not respond to models of the males’ calling songs (CSs) and those that respond (60%) exhibit quantitative differences in their responses. In virgin females, the AN2 neuron receives excitatory stimulation from the cricket’s ear and responds selectively to model CSs that represent the CSs of calling males. This selective response is very significantly correlated with the same female’s behavioral response to that call. In many male-exposed females, the AN2 neuron does not respond selectively to the CSs that represent calling males. This difference is the result of inhibitory input from the ON1 auditory neuron that in many male-exposed females, “destroys” AN2’s selective response to models of a calling male’s calling song. AN2s in virgin females that are “forced” to respond to model CSs similarly to the AN2 responses in male-exposed females are highly correlated with the failure of the virgin female to respond phonotactically to that CS