Meeting Abstract

P2.116  Friday, Jan. 4  Corazonin neurons function in dimorphic circuits to modulate dopamine signaling in Drosophila ZHAO, Yan*; JOHNSON, Erik C; Wake Forest University zhaoy5@wfu.edu

Corazonin is a neuropeptide transmitters found throughout the arthropods and shares homology with vertebrate Gonadotropin releasing hormone. While in Drosophila, the functions of corazonin signaling are unknown; its actions in other insects are consistent with roles in mediating behavioral and physiological responses to stress. We examined the potential roles of corazonin in mediating stress behaviors using targeted expression of constructs to alter the physiology of corazonin neurons. Introduction of the proapoptotic gene, reaper, which leads to the death of these cells, uniformly leads to increased resistance to osmotic, metabolic, and oxidative stresses in both males and females. Alterations of corazonin neuronal excitability revealed a strong sexual dimorphism, as in males hypersecretion and hyposecretion of corazonin leads to increased sensitivity and resistance, respectively. In females, these manipulations did not alter stress sensitivity. Analysis of locomotor activity, under normal and stressed conditions were similar; graded amounts of locomotion in males that correlate with corazonin secretion and wild-type activity levels in females. We have evidence that dopamine plays a pivotal role in mediating stress behaviors and measured dopamine levels in flies with normal or altered corazonin function, and find increased dopamine levels in males with lowered corazonin signaling. Based on these results, we propose a model in which corazonin neurons participate in sexual dimorphic circuits that modulate dopaminergic signaling to shape the plasticity of behavioral stress responses.