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Corazonin neurons function in sexually dimorphic circuitry that shape behavioral responses to stress in Drosophila.

Zhao Y, Bretz CA, Hawksworth SA, Hirsh J, Johnson EC - PLoS ONE (2010)

Bottom Line: Silencing and activation of corazonin neurons lead to differential lifespan under stress, and these effects showed a strong dependence on sex.Additionally, altered corazonin neuron physiology leads to fundamental differences in locomotor activity, and these effects were also sex-dependent.These results underscore the importance of central peptidergic processing within the context of stress and place corazonin signaling as a critical feature of neuroendocrine events that shape stress responses and may underlie the inherent sexual dimorphic differences in stress responses.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Wake Forest University, Winston-Salem, North Carolina, United States of America.

ABSTRACT
All organisms are confronted with dynamic environmental changes that challenge homeostasis, which is the operational definition of stress. Stress produces adaptive behavioral and physiological responses, which, in the Metazoa, are mediated through the actions of various hormones. Based on its associated phenotypes and its expression profiles, a candidate stress hormone in Drosophila is the corazonin neuropeptide. We evaluated the potential roles of corazonin in mediating stress-related changes in target behaviors and physiologies through genetic alteration of corazonin neuronal excitability. Ablation of corazonin neurons confers resistance to metabolic, osmotic, and oxidative stress, as measured by survival. Silencing and activation of corazonin neurons lead to differential lifespan under stress, and these effects showed a strong dependence on sex. Additionally, altered corazonin neuron physiology leads to fundamental differences in locomotor activity, and these effects were also sex-dependent. The dynamics of altered locomotor behavior accompanying stress was likewise altered in flies with altered corazonin neuronal function. We report that corazonin transcript expression is altered under starvation and osmotic stress, and that triglyceride and dopamine levels are equally impacted in corazonin neuronal alterations and these phenotypes similarly show significant sexual dimorphisms. Notably, these sexual dimorphisms map to corazonin neurons. These results underscore the importance of central peptidergic processing within the context of stress and place corazonin signaling as a critical feature of neuroendocrine events that shape stress responses and may underlie the inherent sexual dimorphic differences in stress responses.

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Corazonin transcript levels decrease during stress.Top: Representative gels from experiments of corazonin and RP49 expression in the w1118 genotype under starvation, osmotic, and oxidative stress. Bottom: Changes in corazonin expression under different stresses for noted times. Data are represented as a % of basal (unstressed) and are normalized to RP49. Starvation and osmotic stress cause a decline in corazonin expression and rises as a function of stress duration. Oxidative stress produces no change in corazonin expression.
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pone-0009141-g007: Corazonin transcript levels decrease during stress.Top: Representative gels from experiments of corazonin and RP49 expression in the w1118 genotype under starvation, osmotic, and oxidative stress. Bottom: Changes in corazonin expression under different stresses for noted times. Data are represented as a % of basal (unstressed) and are normalized to RP49. Starvation and osmotic stress cause a decline in corazonin expression and rises as a function of stress duration. Oxidative stress produces no change in corazonin expression.

Mentions: The above results demonstrate a requirement of corazonin neurons within multiple behavioral and physiological responses accompanying different stresses. However, a possible explanation for these phenotypic differences is that corazonin neurons participate in the developmental organization of responsible central and/or peripheral targets as opposed to acute actions of these neurons during stress. To begin to differentiate between these possibilities, we measured corazonin transcript expression during periods of stress. To gauge relative expression of the corazonin transcript, we normalized levels to those ascertained for RP49. These experiments show a decrease in corazonin transcript expression following starvation and osmotic stress, and such decreases were more pronounced in males (Figure 7). This rapid decline of expression levels gradually returns to normal levels as a function of starvation stress duration in males. Corazonin transcript levels were largely unaffected by oxidative stress.


Corazonin neurons function in sexually dimorphic circuitry that shape behavioral responses to stress in Drosophila.

Zhao Y, Bretz CA, Hawksworth SA, Hirsh J, Johnson EC - PLoS ONE (2010)

Corazonin transcript levels decrease during stress.Top: Representative gels from experiments of corazonin and RP49 expression in the w1118 genotype under starvation, osmotic, and oxidative stress. Bottom: Changes in corazonin expression under different stresses for noted times. Data are represented as a % of basal (unstressed) and are normalized to RP49. Starvation and osmotic stress cause a decline in corazonin expression and rises as a function of stress duration. Oxidative stress produces no change in corazonin expression.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2818717&req=5

pone-0009141-g007: Corazonin transcript levels decrease during stress.Top: Representative gels from experiments of corazonin and RP49 expression in the w1118 genotype under starvation, osmotic, and oxidative stress. Bottom: Changes in corazonin expression under different stresses for noted times. Data are represented as a % of basal (unstressed) and are normalized to RP49. Starvation and osmotic stress cause a decline in corazonin expression and rises as a function of stress duration. Oxidative stress produces no change in corazonin expression.
Mentions: The above results demonstrate a requirement of corazonin neurons within multiple behavioral and physiological responses accompanying different stresses. However, a possible explanation for these phenotypic differences is that corazonin neurons participate in the developmental organization of responsible central and/or peripheral targets as opposed to acute actions of these neurons during stress. To begin to differentiate between these possibilities, we measured corazonin transcript expression during periods of stress. To gauge relative expression of the corazonin transcript, we normalized levels to those ascertained for RP49. These experiments show a decrease in corazonin transcript expression following starvation and osmotic stress, and such decreases were more pronounced in males (Figure 7). This rapid decline of expression levels gradually returns to normal levels as a function of starvation stress duration in males. Corazonin transcript levels were largely unaffected by oxidative stress.

Bottom Line: Silencing and activation of corazonin neurons lead to differential lifespan under stress, and these effects showed a strong dependence on sex.Additionally, altered corazonin neuron physiology leads to fundamental differences in locomotor activity, and these effects were also sex-dependent.These results underscore the importance of central peptidergic processing within the context of stress and place corazonin signaling as a critical feature of neuroendocrine events that shape stress responses and may underlie the inherent sexual dimorphic differences in stress responses.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Wake Forest University, Winston-Salem, North Carolina, United States of America.

ABSTRACT
All organisms are confronted with dynamic environmental changes that challenge homeostasis, which is the operational definition of stress. Stress produces adaptive behavioral and physiological responses, which, in the Metazoa, are mediated through the actions of various hormones. Based on its associated phenotypes and its expression profiles, a candidate stress hormone in Drosophila is the corazonin neuropeptide. We evaluated the potential roles of corazonin in mediating stress-related changes in target behaviors and physiologies through genetic alteration of corazonin neuronal excitability. Ablation of corazonin neurons confers resistance to metabolic, osmotic, and oxidative stress, as measured by survival. Silencing and activation of corazonin neurons lead to differential lifespan under stress, and these effects showed a strong dependence on sex. Additionally, altered corazonin neuron physiology leads to fundamental differences in locomotor activity, and these effects were also sex-dependent. The dynamics of altered locomotor behavior accompanying stress was likewise altered in flies with altered corazonin neuronal function. We report that corazonin transcript expression is altered under starvation and osmotic stress, and that triglyceride and dopamine levels are equally impacted in corazonin neuronal alterations and these phenotypes similarly show significant sexual dimorphisms. Notably, these sexual dimorphisms map to corazonin neurons. These results underscore the importance of central peptidergic processing within the context of stress and place corazonin signaling as a critical feature of neuroendocrine events that shape stress responses and may underlie the inherent sexual dimorphic differences in stress responses.

Show MeSH
Related in: MedlinePlus