Biology subjects

Musso, P.-Y.

Publications and source records attributed to Musso, P.-Y..

6 recordsLinked to original sources

bioRxiv2026

The BPI-like TULIP domain proteins of Drosophila melanogaster: a novel class of candidate odorant transporters.

TULIP (TUbular LIPid binding) domain proteins (TDPs) are found in all living organisms including bacteria. They have various documented functions, some of which clearly related to their intra- or extracellular lipid transfer activities. Extracellular, BPI-related TDPs of insects (B-TDPs, also known as Takeout-related proteins), are often found in chemosensory organs, but little is known regarding their exact location or how they could contribute to olfaction or gustation. We have surveyed and updated the full set of Drosophila B-TDPs and found that roughly 50% are overexpressed in chemosensory organs. Focusing on three genes clustered on the third chromosome, we provide evidence that at least one of the encoded proteins is secreted in the lymph cavity housing the dendrites of olfactory neurons. Biochemical data give support for a putative function of B-TDPs as odorant transporters, but loss-of-function analyses also hint to a potential role as a barrier against plant-emitted terpenoids.

animal behavior and cognition↗

bioRxiv2025

Artificial sweeteners differentially activate sweet and bitter gustatory neurons in Drosophila

Artificial sweeteners are highly sweet, non-nutritive compounds that have become increasingly popular over recent decades despite research suggesting that their consumption has unintended consequences. Specifically, there is evidence suggesting that some of these chemicals interact with bitter taste receptors, implying that sweeteners likely generate complex chemosensory signals. Here, we report the basic sensory characteristics of sweeteners in Drosophila, a common model system used to study the impacts of diet, and find that all noncaloric sweeteners inhibited appetitive feeding responses at higher concentrations. At a cellular level, we found that sucralose and rebaudioside A co-activated sweet and bitter gustatory receptor neurons (GRNs), two populations that reciprocally impact feeding behavior, while aspartame only activated bitter cells. We assessed the behavioral impacts of sweet and bitter co-activation and found that low concentrations of sucralose signal appetitive feeding while high concentrations signal feeding aversion. Finally, silencing bitter GRNs reduced the aversive signal elicited by high concentrations of sucralose and significantly increased sucralose feeding behaviors. Together, we conclude that artificial sweeteners generate a gustatory signal that is more complex than "sweetness" alone, and this bitter co-activation has behaviorally relevant effects on feeding that may help flies flexibly respond to these unique compounds.

neuroscience↗

bioRxiv2021

Optogenetic induction of appetitive and aversive taste memories in Drosophila

Tastes are typically thought to evoke innate appetitive or aversive behaviours, prompting food acceptance or rejection. However, research in Drosophila melanogaster indicates that taste responses can be modified through experience-dependent changes in mushroom body circuits. In this study, we develop a novel taste learning paradigm using closed-loop optogenetics. We find that appetitive and aversive taste memories can be formed by pairing gustatory stimuli with optogenetic activation of sensory or dopaminergic neurons associated with reward or punishment. As with olfactory memories, distinct dopaminergic subpopulations drive the parallel formation of short- and long-term appetitive memories. Long-term memories are protein synthesis-dependent and have energetic requirements that are satisfied by a variety of caloric food sources or by direct stimulation of MB-MP1 dopaminergic neurons. Our paradigm affords new opportunities to probe plasticity mechanisms within the taste system and understand the extent to which taste responses depend on experience.

neuroscience↗

bioRxiv2021

A neural circuit linking two sugar sensors regulates satiety-dependent fructose drive in Drosophila.

Ingestion of certain sugars leads to activation of fructose sensors within the brain of flies, which then sustain or terminate feeding behavior depending on internal state. Here, we describe a three-part neural circuit that links satiety with fructose sensing. We show that AB-FBl8 neurons of the Fan-shaped body display oscillatory calcium activity when hemolymph glycemia is high, and that these oscillations require synaptic input from SLP-AB neurons projecting from the protocerebrum to the asymmetric body. Suppression of activity in this circuit, either by starvation or genetic silencing, promotes specific drive for fructose ingestion. Moreover, neuropeptidergic signaling by tachykinin bridges fan-shaped body activity and Gr43a-mediated fructose sensing. Together, our results demonstrate how a three-layer neural circuit links the detection of two sugars to impart precise satiety-dependent control over feeding behavior.

neuroscience↗

bioRxiv2021

Modulation of taste sensitivity by the olfactory system in Drosophila

An animals sensory percepts are not raw representations of the outside world. Rather, they are constructs influenced by many factors including the species, past experiences, and internal states. One source of perceptual variability that has fascinated researchers for decades is the effect of losing one sensory modality on the performance of another1. Typically, dysfunction of one sense has been associated with elevated function of others, creating a type of sensory homeostasis2. For example, people with vision loss have been reported to demonstrate enhanced tactile and auditory functions, and deafness has been associated with heightened attention to visual inputs for communication3,4. By contrast, smell and taste--the two chemosensory modalities--are so intrinsically linked in their contributions to flavor that loss of smell is often anecdotally reported as leading to deficiencies in taste5-8. However, human studies specifically examining taste are mixed and generally do not support this widely-held belief, and data from animal models is largely lacking9. Here, we examine the impact of olfactory dysfunction on taste sensitivity in Drosophila melanogaster. We find that partial loss of olfactory input (hyposmia) dramatically enhances flies sensitivity to both appetitive (sugar, low salt) and aversive (bitter, high salt) tastes. This taste enhancement is starvation-independent and occurs following suppression of either first- or second-order olfactory neurons. Moreover, optogenetically increasing olfactory inputs reduces taste sensitivity. Finally, we observed that taste enhancement is not encoded in the activity of peripheral gustatory sensory neurons, but is associated with elevated sugar responses in protocerebrum anterior medial (PAM) dopaminergic neurons of the mushroom bodies. These results suggest a level of homeostatic control over chemosensation, where flies compensate for lack of olfactory input by increasing the salience of taste information.

neuroscience↗

bioRxiv2018

The STROBE: a system for closed-looped optogenetic control of freely feeding flies

Manipulating feeding circuits in freely moving animals is challenging, in part because the timing of sensory inputs is affected by the animals behavior. To address this challenge in Drosophila, we developed the Sip-Triggered Optogenetic Behavior Enclosure (\"STROBE\"). The STROBE is a closed-looped system for real-time optogenetic activation of feeding flies, designed to evoke neural excitation coincident with food contact. We demonstrate that optogenetic stimulation of sweet sensory neurons in the STROBE drives attraction to tasteless food, while activation of bitter sensory neurons promotes avoidance. Moreover, feeding behavior in the STROBE is modified by the flys internal state, as well as the presence of chemical taste ligands. We also find that mushroom body dopaminergic neurons and their respective post-synaptic partners drive opposing feeding behaviors following activation. Together, these results establish the STROBE as a new tool for dissecting fly feeding circuits and suggest a role for mushroom body circuits in processing naive taste responses.

neuroscience↗