Protein kinase modulation of the neurocircuitry underlying phonotaxis in the cricket Acheta domesticus
Presenter Status
Student, Andrews University
Second Presenter Status
Student, Andrews University
Third Presenter Status
Professor, Department of Biology
Preferred Session
Poster Session
Location
Berrien Springs, MI
Start Date
20-10-2023 2:00 PM
End Date
20-10-2023 3:00 PM
Presentation Abstract
Juvenile hormone is a key regulator in the development, physiology and behavior of insects, but little has been reported about the mechanisms of action of this hormone in the cricket model system. In the species Acheta domesticus, young, virgin females with elevated levels of juvenile hormone, respond selectively to computer-generated calls which mimic the calls of conspecific males. As these females age, they become increasingly less selective, responding to a wider range of calls. This reduction in their ability to discriminate attractive calls has been correlated with reduced levels of juvenile hormone. Similarly, a decline in juvenile hormone levels has been demonstrated to influence the response of the L3 prothoracic auditory neuron in A. domesticus. As these crickets age, both the quantity and pattern of response in L3 changes. L3 is presumably a key constituent of the prothoracic auditory network responsible for encoding and processing information which it then sends to the brain. In A. domesticus, this neuron has been posited to play a role in selective phonotaxis as demonstrated by experiments where inactivation of L3 in previously selective females caused them to behave unselectively. Although the details of the precise molecular targets of juvenile hormone in the cricket nervous system remain to be discovered, we know that one of the ways in which juvenile hormone elicits its actions in other insects is through a protein kinase C (PKC) signaling pathway. Using a pharmacological approach, we have tested the effect of manipulating PKC activity on L3’s spiking and on the phonotactic behavior of A. domesticus. Bath application of the synthetic biomolecule H7, which has been shown to inhibit PKC, resulted in the inhibition of L3’s spiking activity. This suppression was reversed upon removal of H7. Further, intra-ganglionic nano injection of H7 to selective crickets reduced their phonotactic responsiveness across the full range of syllable periods presented, which contrasted with the control group which remained phonotactically selective following nano injection of saline. Taken together, the findings of the H7- induced decline in L3 activity, the H7-induced decline in phonotactic responsiveness and the already demonstrated juvenile hormone associated regulation of phonotaxis, point to L3 being part of the neural network under modulation by a complex interplay of regulatory agents including second messenger signaling cascade.
Protein kinase modulation of the neurocircuitry underlying phonotaxis in the cricket Acheta domesticus
Berrien Springs, MI
Juvenile hormone is a key regulator in the development, physiology and behavior of insects, but little has been reported about the mechanisms of action of this hormone in the cricket model system. In the species Acheta domesticus, young, virgin females with elevated levels of juvenile hormone, respond selectively to computer-generated calls which mimic the calls of conspecific males. As these females age, they become increasingly less selective, responding to a wider range of calls. This reduction in their ability to discriminate attractive calls has been correlated with reduced levels of juvenile hormone. Similarly, a decline in juvenile hormone levels has been demonstrated to influence the response of the L3 prothoracic auditory neuron in A. domesticus. As these crickets age, both the quantity and pattern of response in L3 changes. L3 is presumably a key constituent of the prothoracic auditory network responsible for encoding and processing information which it then sends to the brain. In A. domesticus, this neuron has been posited to play a role in selective phonotaxis as demonstrated by experiments where inactivation of L3 in previously selective females caused them to behave unselectively. Although the details of the precise molecular targets of juvenile hormone in the cricket nervous system remain to be discovered, we know that one of the ways in which juvenile hormone elicits its actions in other insects is through a protein kinase C (PKC) signaling pathway. Using a pharmacological approach, we have tested the effect of manipulating PKC activity on L3’s spiking and on the phonotactic behavior of A. domesticus. Bath application of the synthetic biomolecule H7, which has been shown to inhibit PKC, resulted in the inhibition of L3’s spiking activity. This suppression was reversed upon removal of H7. Further, intra-ganglionic nano injection of H7 to selective crickets reduced their phonotactic responsiveness across the full range of syllable periods presented, which contrasted with the control group which remained phonotactically selective following nano injection of saline. Taken together, the findings of the H7- induced decline in L3 activity, the H7-induced decline in phonotactic responsiveness and the already demonstrated juvenile hormone associated regulation of phonotaxis, point to L3 being part of the neural network under modulation by a complex interplay of regulatory agents including second messenger signaling cascade.