@article {69154,
	title = {Failure to mate enhances investment in behaviors that may promote mating reward and impairs the ability to cope with stressors via a subpopulation of Neuropeptide F receptor neurons.},
	journal = {PLoS Genetics},
	volume = {20},
	year = {2024},
	month = {2024 Jan 18},
	pages = {e1011054},
	abstract = {<p>Living in dynamic environments such as the social domain, where interaction with others determines the reproductive success of individuals, requires the ability to recognize opportunities to obtain natural rewards and cope with challenges that are associated with achieving them. As such, actions that promote survival and reproduction are reinforced by the brain reward system, whereas coping with the challenges associated with obtaining these rewards is mediated by stress-response pathways, the activation of which can impair health and shorten lifespan. While much research has been devoted to understanding mechanisms underlying the way by which natural rewards are processed by the reward system, less attention has been given to the consequences of failure to obtain a desirable reward. As a model system to study the impact of failure to obtain a natural reward, we used the well-established courtship suppression paradigm in Drosophila melanogaster as means to induce repeated failures to obtain sexual reward in male flies. We discovered that beyond the known reduction in courtship actions caused by interaction with non-receptive females, repeated failures to mate induce a stress response characterized by persistent motivation to obtain the sexual reward, reduced male-male social interaction, and enhanced aggression. This frustrative-like state caused by the conflict between high motivation to obtain sexual reward and the inability to fulfill their mating drive impairs the capacity of rejected males to tolerate stressors such as starvation and oxidative stress. We further show that sensitivity to starvation and enhanced social arousal is mediated by the disinhibition of a small population of neurons that express receptors for the fly homologue of neuropeptide Y. Our findings demonstrate for the first time the existence of social stress in flies and offers a framework to study mechanisms underlying the crosstalk between reward, stress, and reproduction in a simple nervous system that is highly amenable to genetic manipulation.</p>
},
	keywords = {Animals, Drosophila melanogaster, Female, Humans, Male, Neurons, Neuropeptides, Reproduction, Reward, Sexual Behavior, Animal},
	issn = {1553-7404},
	doi = {10.1371/journal.pgen.1011054},
	author = {Ryvkin, Julia and Omesi, Liora and Kim, Yong-Kyu and Levi, Mali and Pozeilov, Hadar and Barak-Buchris, Lital and Agranovich, Bella and Abramovich, Ifat and Gottlieb, Eyal and Jacob, Avi and N{\"a}ssel, Dick R and Heberlein, Ulrike and Shohat-Ophir, Galit}
}
@article {49013,
	title = {Repetitive aggressive encounters generate a long-lasting internal state in Drosophila melanogaster males.},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {115},
	year = {2018},
	month = {2018 Jan 16},
	pages = {1099-104},
	abstract = {<p>Multiple studies have investigated the mechanisms of aggressive behavior in Drosophila; however, little is known about the effects of chronic fighting experience. Here, we investigated if repeated fighting encounters would induce an internal state that could affect the expression of subsequent behavior. We trained wild-type males to become winners or losers by repeatedly pairing them with hypoaggressive or hyperaggressive opponents, respectively. As described previously, we observed that chronic losers tend to lose subsequent fights, while chronic winners tend to win them. Olfactory conditioning experiments showed that winning is perceived as rewarding, while losing is perceived as aversive. Moreover, the effect of chronic fighting experience generalized to other behaviors, such as gap-crossing and courtship. We propose that in response to repeatedly winning or losing aggressive encounters, male flies form an internal state that displays persistence and generalization; fight outcomes can also have positive or negative valence. Furthermore, we show that the activities of the PPL1-γ1pedc dopaminergic neuron and the MBON-γ1pedc\&gt;α/β mushroom body output neuron are required for aversion to an olfactory cue associated with losing fights.</p>
},
	issn = {1091-6490},
	doi = {10.1073/pnas.1716612115},
	author = {Kim, Yong-Kyu and Saver, Mathias and Simon, Jasper and Kent, Clement F and Shao, Lisha and Eddison, Mark and Agrawal, Pavan and Texada, Michael and Truman, James W and Heberlein, Ulrike}
}
