Modulation of Phonotaxis by Monoamines
Pharmacological agents (drugs) are powerful tools for dissecting the molecular and biochemical mechanisms underlying processes not readily accessible with conventional tools. In a preliminary study, we have used mianserin, an antagonist of monoamine neurotransmitters in the central nervous system (CNS) of vertebrates, to identify the neurotransmitters involved in the processing of auditory signals in the CNS of an insect model. N anoinj ection of mianserin into the prothoracic ganglion of A. domesticus whose phonotactic responsiveness had been established resulted in a marked decrease in their responsiveness to a male call. Control crickets injected with drug-free vehicle did not show changes in their phonotaxis. We conclude, based on the results of this limited sample (N <15 animals per treatment), that monoamines are involved in mediating phonotactic behavior in female A. domesticus. We propose to broaden this study by using a larger sample and test more antagonists to confirm these findings. We further propose to examine the effects of mianserin and other antagonists on the activity of auditory neurons in the prothoracic ganglion. We particularly plan to target intemeuron L3, a cell whose response properties mirror the phonotactic behavior of female A. domesticus.