Serotonin Signals Overcome Loser Mentality in Drosophila

Krama

Front. Behav. Neurosci.

et al. 2021

When organisms’ environmental conditions vary unpredictably in time, it can be advantageous for individuals to hedge their phenotypic bets. It has been shown that a bet-hedging strategy possibly underlies the high inter-individual diversity of phototactic choice in Drosophila melanogaster. This study shows that fruit flies from a population living in a boreal and relatively unpredictable climate have more variable variable phototactic biases than fruit flies from a more stable tropical climate, consistent with bet-hedging theory. We experimentally show that phototactic variability of D. melanogaster is regulated by the neurotransmitter serotonin (5-HT), which acts as a suppressor of the variability of phototactic choices. When fed 5-HT precursor, boreal flies exhibited lower variability, and they were insensitive to 5-HT inhibitor. The opposite pattern was seen in the tropical flies. Thus, the reduction of 5-HT in fruit flies’ brains may be the mechanistic basis of an adaptive bet-hedging strategy in a less predictable boreal climate.

Section: Groups and Drug Treatmentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Serotoninergic Modulation of Phototactic Variability Underpins a Bet-Hedging Strategy in Drosophila melanogaster

Krama

Front. Behav. Neurosci.

et al. 2021

“…It is evident that winning and losing have both short- and long-term effects, that memory of defeat lasts longer, and that repeated defeats induce a persistent loser effect, which is dependent on de novo protein synthesis ( Trannoy et al, 2016 ). Neuromodulators play an important role in controlling aggressive behaviors ( Asahina, 2017 ), and activating a small subset of serotonergic neurons is sufficient to overcome this “loser mentality,” restoring mating motivation in losers ( Hu et al, 2020 ). As courtship and aggression share common neuronal nodes in both males ( Hoopfer et al, 2015 ; Koganezawa et al, 2016 ) and females ( Deutsch et al, 2020 ; Schretter et al, 2020 ), it is possible that previous aggressive behaviors impact these common centers, modifying both aggressive and mating drives based on previous experience.…”

Section: Flexible Circuits For Mating Behaviors In Mice and Fliesmentioning

confidence: 99%

Flexibility of neural circuits regulating mating behaviors in mice and flies

Karigo

Deutsch

2022

Front. Neural Circuits

Mating is essential for the reproduction of animal species. As mating behaviors are high-risk and energy-consuming processes, it is critical for animals to make adaptive mating decisions. This includes not only finding a suitable mate, but also adapting mating behaviors to the animal’s needs and environmental conditions. Internal needs include physical states (e.g., hunger) and emotional states (e.g., fear), while external conditions include both social cues (e.g., the existence of predators or rivals) and non-social factors (e.g., food availability). With recent advances in behavioral neuroscience, we are now beginning to understand the neural basis of mating behaviors, particularly in genetic model organisms such as mice and flies. However, how internal and external factors are integrated by the nervous system to enable adaptive mating-related decision-making in a state- and context-dependent manner is less well understood. In this article, we review recent knowledge regarding the neural basis of flexible mating behaviors from studies of flies and mice. By contrasting the knowledge derived from these two evolutionarily distant model organisms, we discuss potential conserved and divergent neural mechanisms involved in the control of flexible mating behaviors in invertebrate and vertebrate brains.

“…circuits (He et al, 2019;Liu et al, 2020), learning and memory circuits (Scaplen et al, 2020;Georganta et al, 2021), and circuits controlling aggression (Hu et al, 2020;Wu et al, 2020), social attraction (Sun et al, 2020), and circadian rhythm and sleep (Guo et al, 2018;Dreyer et al, 2019;Liu et al, 2019;Duhart et al, 2020). It has also been applied to identify neuropeptide synapses (Zandawala et al, 2018(Zandawala et al, , 2021 and other neuronal targets, such as the adipose tissue (Scopelliti et al, 2019).…”

Section: Applications Of Genetic Transsynaptic Toolsmentioning

confidence: 99%

Genetic Transsynaptic Techniques for Mapping Neural Circuits in Drosophila

2021

Front. Neural Circuits

A neural circuit is composed of a population of neurons that are interconnected by synapses and carry out a specific function when activated. It is the structural framework for all brain functions. Its impairments often cause diseases in the nervous system. To understand computations and functions in a brain circuit, it is of crucial importance to identify how neurons in this circuit are connected. Genetic transsynaptic techniques provide opportunities to efficiently answer this question. These techniques label synapses or across synapses to unbiasedly label synaptic partners. They allow for mapping neural circuits with high reproducibility and throughput, as well as provide genetic access to synaptically connected neurons that enables visualization and manipulation of these neurons simultaneously. This review focuses on three recently developed Drosophila genetic transsynaptic tools for detecting chemical synapses, highlights their advantages and potential pitfalls, and discusses the future development needs of these techniques.