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Cold Spring Harbor Protocols Jun 2023The ability to modify behavior as a result of previous experience allows an organism to adapt to changes in its environment. Even innate behaviors, like feeding...
The ability to modify behavior as a result of previous experience allows an organism to adapt to changes in its environment. Even innate behaviors, like feeding initiation, can change if previously associated with a noxious stimulus. Here, we describe a taste memory assay pairing appetitive and bitter tastants, resulting in aversive taste conditioning. By training a fly to associate sweet sucrose applied to the tarsus with bitter quinine applied to the proboscis, flies quickly learn to suppress the reflexive proboscis extension to sucrose, providing a bioassay for behavioral and molecular plasticity. This single-fly taste memory assay may be applied to adult of any genetic background and allows for interrogation of the neural circuitry and molecular processes encoding memories while simultaneously measuring behavior. Unlike many other memory assays, this system requires few custom components, and therefore can be easily established in laboratories with minimal expertise in the study of fly behavior.
Topics: Animals; Drosophila; Taste; Taste Perception; Sucrose; Drosophila melanogaster
PubMed: 36787963
DOI: 10.1101/pdb.prot108093 -
Cold Spring Harbor Protocols Jun 2023The ability to distinguish between food sources that are good and provide nutrients and those that are potentially dangerous is crucial to the survival of an organism....
The ability to distinguish between food sources that are good and provide nutrients and those that are potentially dangerous is crucial to the survival of an organism. Here, we describe a taste assay that measures the reflexive feeding response to a given tastant. To examine taste preference for a soluble compound, an appetitive tastant is applied to the proboscis, and the proportion of proboscis extensions are recorded. This single-fly assay may be applied to adult of any genetic background and facilities examination of the neural circuitry and molecular processes encoding the reflexive taste response. Furthermore, this assay requires few custom components and therefore can be easily established in laboratories with minimal expertise in the study of fly behavior.
Topics: Animals; Drosophila; Taste; Taste Perception; Feeding Behavior; Biological Assay; Drosophila melanogaster
PubMed: 36787966
DOI: 10.1101/pdb.prot108092 -
BMJ Open Ophthalmology 2021Proboscis lateralis (PL) is a rare congenital malformation of the craniofacial structure with varied clinical associations. None of the studies documented a discrete... (Review)
Review
Proboscis lateralis (PL) is a rare congenital malformation of the craniofacial structure with varied clinical associations. None of the studies documented a discrete review of ophthalmic presentations in PL. The principal aim of the present study is to explore the ophthalmic manifestations of PL. The ancillary goal is to derive a relationship between congenital deformity in PL and various ophthalmic anomalies. Databases were searched in order to obtain articles related to PL. A qualitative systematic analysis of 100 subjects was performed. In PL, eyelid coloboma (32.6%) is the most common ocular feature, followed by hypertelorism (25.3%), iris coloboma (22.4%), lacrimal system abnormality (20.7%), malpositioned eyebrow (14.4%) and retinochoroidal coloboma (12.9%). Sinonasal deformity is the most common systemic abnormality, detected in 87.9% of cases of PL, as compared with central nervous system involvement (56.2%) and other anomalies. The analysis showed a strong significant association between brain abnormalities and hypertelorism (p=0.000) and between brain abnormalities and micro-ophthalmia/anophthalmia (p=0.000). Statistically significant association was noted between cumulative ocular abnormalities and cumulative systemic abnormalities (p=0.001). The present study on PL reviewed the salient features of this rare congenital disorder. The study outcome provides a new aspect to concomitant ocular abnormalities. This study supports the view that other congenital anomalies in cases of PL had significant influence on certain ophthalmic anomalies.
PubMed: 34395913
DOI: 10.1136/bmjophth-2020-000558 -
Biology Nov 2022flies use their proboscis to taste and distinguish edible compounds from toxic compounds. With their proboscis, flies can detect sex pheromones at a close distance or...
flies use their proboscis to taste and distinguish edible compounds from toxic compounds. With their proboscis, flies can detect sex pheromones at a close distance or by contact. Most of the known proteins associated with probosci's detection belong to gustatory receptor families. To extend our knowledge of the proboscis-taste proteins involved in chemo-detection, we used a proteomic approach to identify soluble proteins from Drosophila females and males. This investigation, performed with hundreds of dissected proboscises, was initiated by the chromatographic separation of tryptic peptides, followed by tandem mass spectrometry, allowing for femtomole detection sensitivity. We found 586 proteins, including enzymes, that are involved in intermediary metabolism and proteins dedicated to various functions, such as nucleic acid metabolism, ion transport, immunity, digestion, and organ development. Among 60 proteins potentially involved in chemosensory detection, we identified two odorant-binding proteins (OBPs), i.e., OBP56d (which showed much higher expression in females than in males) and OBP19d. Because OBP56d was also reported to be more highly expressed in the antennae of females, this protein can be involved in the detection of both volatile and contact male pheromone(s). Our proteomic study paves the way to better understand the complex role of Drosophila proboscis in the chemical detection of food and pheromonal compounds.
PubMed: 36421401
DOI: 10.3390/biology11111687 -
BioRxiv : the Preprint Server For... Nov 2023Sleep is an evolutionarily conserved behavior, whose function is unknown. Here, we present a method for deep phenotyping of sleep in , consisting of a high-resolution...
Sleep is an evolutionarily conserved behavior, whose function is unknown. Here, we present a method for deep phenotyping of sleep in , consisting of a high-resolution video imaging system, coupled with closed-loop laser perturbation to measure arousal threshold. To quantify sleep-associated microbehaviors, we trained a deep-learning network to annotate body parts in freely moving flies and developed a semi-supervised computational pipeline to classify behaviors. Quiescent flies exhibit a rich repertoire of microbehaviors, including proboscis pumping (PP) and haltere switches, which vary dynamically across the night. Using this system, we characterized the effects of optogenetically activating two putative sleep circuits. These data reveal that activating dFB neurons produces micromovements, inconsistent with sleep, while activating R5 neurons triggers PP followed by behavioral quiescence. Our findings suggest that sleep in is polyphasic with different stages and set the stage for a rigorous analysis of sleep and other behaviors in this species.
PubMed: 37961473
DOI: 10.1101/2023.10.30.564733 -
Frontiers in Physiology 2022Honeybees () need their fine sense of taste to evaluate nectar and pollen sources. Gustatory receptors (Grs) translate taste signals into electrical responses....
Honeybees () need their fine sense of taste to evaluate nectar and pollen sources. Gustatory receptors (Grs) translate taste signals into electrical responses. experiments have demonstrated collective responses of the whole Gr-set. We here disentangle the contributions of all three honeybee sugar receptors (AmGr1-3), combining CRISPR/Cas9 mediated genetic knock-out, electrophysiology and behaviour. We show an expanded sugar spectrum of the AmGr1 receptor. Mutants lacking AmGr1 have a reduced response to sucrose and glucose but not to fructose. AmGr2 solely acts as co-receptor of AmGr1 but not of AmGr3, as we show by electrophysiology and using bimolecular fluorescence complementation. Our results show for the first time that AmGr2 is indeed a functional receptor on its own. Intriguingly, AmGr2 mutants still display a wildtype-like sugar taste. AmGr3 is a specific fructose receptor and is not modulated by a co-receptor. Eliminating AmGr3 while preserving AmGr1 and AmGr2 abolishes the perception of fructose but not of sucrose. Our comprehensive study on the functions of AmGr1, AmGr2 and AmGr3 in honeybees is the first to combine investigations on sugar perception at the receptor level and simultaneously . We show that honeybees rely on two gustatory receptors to sense all relevant sugars.
PubMed: 36714315
DOI: 10.3389/fphys.2022.1089669 -
Insects Nov 2021The proboscis is an important feeding organ for the glossatan moths, mainly adapted to the flower and non-flower visiting habits. The clover cutworm, Rottemberg, and...
The proboscis is an important feeding organ for the glossatan moths, mainly adapted to the flower and non-flower visiting habits. The clover cutworm, Rottemberg, and the spotted clover moth, (Denis & Schiffermuller), are serious polyphagous pests, attacking numerous vegetables and crops, resulting in huge economic losses. However, the feeding behavior and mechanisms of the adult stage remain unsatisfactorily explored. In this study, the proboscis morphology of and are described in detail using scanning electron microscopy, with the aim of investigating the morphological differences and feeding behavior of these two species. The proboscises of and are similar in morphology and structure and are divided into three zones (Zone 1-3) based on the morphological changes of the dorsal legulae. Three sensillum types are located on the proboscises of both species, sensilla chaetica, sensilla basiconica, and sensilla styloconica. Significant differences were observed in the length of the proboscis and each zone between these two species, as well as in sensilla size and number. Based on the morphology of the proboscis and associated sensilla, and are potential flower visitors, which was also reinforced by the pollen observed at the proboscis tip. These results will strengthen our understanding of the structure of the proboscis related to the feeding behavior of Noctuidae.
PubMed: 34821792
DOI: 10.3390/insects12110992 -
Cold Spring Harbor Protocols Jun 2023Peripheral detection of tastants allows animals to detect the dietary value of food and its potential toxicity. Many tastants such as sugars and fats elicit reflexive...
Peripheral detection of tastants allows animals to detect the dietary value of food and its potential toxicity. Many tastants such as sugars and fats elicit reflexive appetitive responses, whereas other foods such as quinine induce aversion. The relative value of food can change in accordance with an animal's internal state and prior experience. Understanding the neural and genetic bases for the detection and response to tastants, as well as how these behaviors change with experience, is central to sensory neuroscience. The presentation of attractive tastants to the proboscis or legs of the fruit fly induces a robust and reflexive proboscis-extension response (PER). This quantifiable response can be used to study the receptors underlying taste detection, the neural circuits involved in sensory processing, and the musculature required for a simple feeding behavior. Furthermore, we have developed a memory assay pairing appetitive and bitter tastants, resulting in aversive taste conditioning, in which the PER response to attractive tastants is diminished. Unlike many memory assays, this assay does not require specialized equipment and can be readily implemented in teaching and research laboratories. Here, we introduce protocols for studying the PER feeding response and aversive taste memory in .
Topics: Animals; Drosophila; Taste; Drosophila melanogaster; Taste Perception; Feeding Behavior
PubMed: 36787965
DOI: 10.1101/pdb.top107864 -
The Journal of Neuroscience : the... Apr 2022Habituated animals retain a latent capacity for robust engagement with familiar stimuli. In most instances, the ability to override habituation is best explained by...
Habituated animals retain a latent capacity for robust engagement with familiar stimuli. In most instances, the ability to override habituation is best explained by postulating that habituation arises from the potentiation of inhibitory inputs onto stimulus-encoding assemblies and that habituation override occurs through disinhibition. Previous work has shown that inhibitory plasticity contributes to specific forms of olfactory and gustatory habituation in Here, we analyze how exposure to a novel stimulus causes override of gustatory (proboscis extension reflex; PER) habituation. While brief sucrose contact with tarsal hairs causes naive to extend their proboscis, persistent exposure reduces PER to subsequent sucrose stimuli. We show that in so habituated animals, either brief exposure of the proboscis to yeast or direct thermogenetic activation of sensory neurons restores PER response to tarsal sucrose stimulation. Similar override of PER habituation can also be induced by brief thermogenetic activation of a population of tyrosine hydroxylase (TH)-positive neurons, a subset of which send projections to the subesophageal zone (SEZ). Significantly, sensory-neuron induced habituation override requires transmitter release from these TH-positive cells. Treatments that cause override specifically influence the habituated state, with no effect on the naive sucrose response across a range of concentrations. Taken together with other findings, these observations in female flies are consistent with a model in which novel taste stimuli trigger activity in dopaminergic neurons which, directly or indirectly, inhibit GABAergic cells that drive PER habituation. The implications of these findings for general mechanisms of attentional and sensory override of habituation are discussed. Habituation can be overcome when a new context requires an enhanced response to a familiar stimulus. However, the underlying mechanisms remain incompletely understood. Previous studies have provided evidence that habituation of the sucrose-induced proboscis extension reflex (PER) in occurs through potentiation of inhibition onto the PER pathway. This work defines controlled protocols for override of PER habituation and uses them to outline the underlying circuit mechanisms. The results presented support a model in which novel taste stimuli cause dishabituation by activating a subset of tyrosine hydroxylase (TH)-expressing neurons that inhibit GABAergic neurons whose potentiation underlies PER habituation. At a general level, these findings further highlight a central role for inhibition and disinhibition in the control of behavioral flexibility.
Topics: Animals; Drosophila; Female; GABAergic Neurons; Habituation, Psychophysiologic; Sensory Receptor Cells; Sucrose; Tyrosine 3-Monooxygenase
PubMed: 35232763
DOI: 10.1523/JNEUROSCI.1842-21.2022