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Toxins Jan 2023Nemerteans (also called Nemertines) are a phylum of predominantly marine worms that use toxins to capture prey and to defend themselves against predators....
Nemerteans (also called Nemertines) are a phylum of predominantly marine worms that use toxins to capture prey and to defend themselves against predators. Hoplonemerteans have a proboscis armed with one or more stylets used in prey capture and are taxonomically divided into Order Monostilifera, whose members possess a single large proboscis stylet, and Order Polystilifera, whose members have multiple small stylets. Many monostiliferans contain alkaloidal toxins, including anabaseine, that stimulate and then desensitize nicotinic acetylcholine receptors that are present in all animals. These compounds also interact with pyridyl chemoreceptors in crustaceans, reducing predation and larval settlement. Anabaseine has been a lead compound in the design of alpha7 nicotinic acetylcholine receptor agonists like GTS-21 (also called DMXBA) to treat disorders of cognition such as Alzheimer's disease and schizophrenia. These drug candidates also display anti-inflammatory activities of potential medical importance. Most polystiliferans live deep in open oceans and are relatively inaccessible. We fortunately obtained two live specimens of a large benthic polystiliferan, (), from the coast of Spain. MS and NMR analyses of the Ehrlich's reagent derivative allowed identification of anabaseine. A spectrophotometric assay for anabaseine, also based on its reaction with Ehrlich's reagent, revealed high concentrations of anabaseine in the body and proboscis. Apparently, the biosynthetic mechanism for producing anabaseine was acquired early in the evolution of the Hoplonemertea, before the monostiliferan-polystiliferan divergence.
Topics: Animals; Receptors, Nicotinic; Nicotinic Agonists; Anabasine; Toxins, Biological
PubMed: 36668866
DOI: 10.3390/toxins15010046 -
PeerJ 2023We critically re-examine 17 records of fossils currently assigned to the lepidopteran superfamily Bombycoidea, which includes the silk moths, emperor moths and hawk...
We critically re-examine 17 records of fossils currently assigned to the lepidopteran superfamily Bombycoidea, which includes the silk moths, emperor moths and hawk moths. These records include subfossils, compression and impression fossils, permineralizations and ichnofossils. We assess whether observable morphological features warrant their confident assignment to the superfamily. None of the examined fossils displays characters that allow unequivocal identification as Sphingidae, but three fossils and a subfossil ( Zhang, Sun and Zhang, 1994, two fossil larvae, and a proboscis in asphaltum) have combinations of diagnostic features that support placement in the family. The identification of a fossil pupa as Bunaeini (Saturniidae) is well supported. The other fossils that we evaluate lack definitive bombycoid and, in several cases, even lepidopteran characters. Some of these dubious fossils have been used as calibration points in earlier studies casting doubt on the resulting age estimates. All fossil specimens reliably assigned to Bombycoidea are relatively young, the earliest fossil evidence of the superfamily dating to the middle Miocene.
Topics: Animals; Fossils; Phylogeny; Moths; Manduca; Larva
PubMed: 37965290
DOI: 10.7717/peerj.16049 -
ELife Jul 2022Taste detection and hunger state dynamically regulate the decision to initiate feeding. To study how context-appropriate feeding decisions are generated, we combined...
Taste detection and hunger state dynamically regulate the decision to initiate feeding. To study how context-appropriate feeding decisions are generated, we combined synaptic resolution circuit reconstruction with targeted genetic access to specific neurons to elucidate a gustatory sensorimotor circuit for feeding initiation in adult . This circuit connects gustatory sensory neurons to proboscis motor neurons through three intermediate layers. Most neurons in this pathway are necessary and sufficient for proboscis extension, a feeding initiation behavior, and respond selectively to sugar taste detection. Pathway activity is amplified by hunger signals that act at select second-order neurons to promote feeding initiation in food-deprived animals. In contrast, the feeding initiation circuit is inhibited by a bitter taste pathway that impinges on premotor neurons, illuminating a local motif that weighs sugar and bitter taste detection to adjust the behavioral outcomes. Together, these studies reveal central mechanisms for the integration of external taste detection and internal nutritive state to flexibly execute a critical feeding decision.
Topics: Animals; Drosophila Proteins; Drosophila melanogaster; Feeding Behavior; Hunger; Sensory Receptor Cells; Sugars; Taste
PubMed: 35791902
DOI: 10.7554/eLife.79887 -
IScience Jan 2024Multimodal cues can improve behavioral responses by enhancing the detection and localization of sensory cues and reducing response times. Across species, studies have...
Multimodal cues can improve behavioral responses by enhancing the detection and localization of sensory cues and reducing response times. Across species, studies have shown that multisensory integration of visual and olfactory cues can improve response accuracy. However, in real-world settings, sensory cues are often noisy; visual and olfactory cues can be deteriorated, masked, or mixed, making the target cue less clear to the receiver. In this study, we use an associative learning paradigm (Free Moving Proboscis Extension Reflex, FMPER) to show that having multimodal cues may improve the accuracy of bees' responses to noisy cues. Adding a noisy visual cue improves the accuracy of response to a noisy olfactory cue, despite neither the clear nor noisy visual cue being sufficient when paired with a novel olfactory cue. This may provide insight into the neural mechanisms underlying multimodal processing and the effects of environmental change on pollination services.
PubMed: 38161424
DOI: 10.1016/j.isci.2023.108587 -
Irish Veterinary Journal 2020Nasal abnormalities are rare in bovines. In humans, nasal deformities are mainly classified as proboscis lateralis or supernumerary nostrils. This report discusses the...
BACKGROUND
Nasal abnormalities are rare in bovines. In humans, nasal deformities are mainly classified as proboscis lateralis or supernumerary nostrils. This report discusses the etiology of triple nostrils in a calf, based on computed tomography, magnetic resonance imaging, and endoscopy.
CASE PRESENTATION
A female Holstein calf presented with triple nostrils. The following abnormalities were observed: (1) formation of a small and flat blind-ended middle nostril between the right and left nostrils; (2) presence of a hair-bearing surface on the muzzle; (3) abnormal curvature of the nasal septum, resulting in a narrower right nasal cavity due to transformation of the nasal bones; and (4) formation of a bone-like structure within the nasal septum. These findings were similar to those of supernumerary nostrils in humans.
CONCLUSIONS
To the best of our knowledge, this represents the first description of a calf with triple nostrils. The use of imaging modalities is necessary for investigating the etiology of triple nostrils.
PubMed: 32864097
DOI: 10.1186/s13620-020-00173-z -
Science Advances Jan 2021Sleep is a highly conserved state, suggesting that sleep's benefits outweigh the increased vulnerability it brings. Yet, little is known about how sleep fulfills its...
Sleep is a highly conserved state, suggesting that sleep's benefits outweigh the increased vulnerability it brings. Yet, little is known about how sleep fulfills its functions. Here, we used video tracking in tethered flies to identify a discrete deep sleep stage in termed proboscis extension sleep, that is defined by repeated stereotyped proboscis extensions and retractions. Proboscis extension sleep is accompanied by highly elevated arousal thresholds and decreased brain activity, indicative of a deep sleep state. Preventing proboscis extensions increases injury-related mortality and reduces waste clearance. Sleep deprivation reduces waste clearance and during subsequent rebound sleep, sleep, proboscis extensions, and waste clearance are increased. Together, these results provide evidence of a discrete deep sleep stage that is linked to a specific function and suggest that waste clearance is a core and ancient function of deep sleep.
PubMed: 33523916
DOI: 10.1126/sciadv.abc2999 -
Case Reports in Radiology 2014A twenty-year-old second gravida presented to the department of radiodiagnosis for routine obstetric ultrasound examination. Ultrasonography revealed a live fetus of 17...
A twenty-year-old second gravida presented to the department of radiodiagnosis for routine obstetric ultrasound examination. Ultrasonography revealed a live fetus of 17 weeks with absent falx, fused thalami, monoventricle, proboscis, and cyclopia. Fetal MRI was performed and the findings were confirmed. Even though ultrasonography is diagnostic in the detection of fetal anomalies, MRI plays a vital role due to its multiplanar capability and excellent soft tissue resolution. The importance of presenting this classical case of alobar holoprosencephaly is to sensitize the clinicians and radiologists to the imaging manifestations of holoprosencephaly and to stress the importance of early diagnosis. If diagnosed in utero at an early stage of pregnancy, termination can be performed and maternal psychological trauma of bearing a deformed fetus can be avoided.
PubMed: 25126440
DOI: 10.1155/2014/724671 -
STAR Protocols Dec 2022Fruit flies sense the features of food that are driven by particle size, including smoothness versus grittiness, by deflection of sensilla decorating the labellum, and...
Fruit flies sense the features of food that are driven by particle size, including smoothness versus grittiness, by deflection of sensilla decorating the labellum, and md-L neurons. We describe adaptation of the proboscis extension response assay, including steps to perform the taste tests and score behavioral responses, to determine preferences to foods with different sized particles. We also describe calcium imaging in GCaMP-expressing flies to assess the responses of md-L neurons to different levels of taste sensilla deflection. For complete details on the use and execution of this protocol, please refer to Li and Montell. (2021).
Topics: Animals; Drosophila; Butterflies; Taste; Sensilla; Food
PubMed: 36386873
DOI: 10.1016/j.xpro.2022.101806 -
Bio-protocol Dec 2023Habituation, the process by which animals learn to ignore insignificant stimuli, facilitates engagement with salient features of the environment. However, neural...
Habituation, the process by which animals learn to ignore insignificant stimuli, facilitates engagement with salient features of the environment. However, neural mechanisms underlying habituation also allow responses to familiar stimuli to be reinstated when such stimuli become potentially significant. Thus, the habituated state must allow a mechanism for habituation override. The remarkably precise knowledge of cell identity, connectivity, and information coding in sensory circuits, as well as the availability of tools to genetically target these cells, makes a valuable and important organism for analysis of habituation and habituation-override mechanisms. Studies of olfactory and gustatory habituation in suggest that potentiation of GABAergic neurons underlies certain timescales of habituation and have specified some elements of a gustatory habituation-override pathway. More detailed understanding of gustatory habituation and habituation-override mechanisms will benefit from access to robust behavioral assays for (a) the proboscis extension reflex (PER) elicited by a sweet stimulus, (b) exposure paradigms that result in PER habituation, and, most critically, (c) manipulations that result in PER-habituation override. Here, we describe simple protocols for persistent sucrose exposure of tarsal hairs that lead to habituation of proboscis extension and for presentation of a novel appetitive stimuli that reinstate robust PER to habituated flies. This detailed protocol of gustatory habituation provides (a) a simple method to induce habituation by continuous exposure of the flies to sucrose for 10 min without leading to ingestion and (b) a novel method to override habituation by presenting yeast to the proboscis. Key features • A protocol for stimulation of 's taste (sugar) sensory neurons that induces gustatory habituation without satiation due to ingestion. • A chemical (yeast) stimulation protocol that rapidly induces habituation override/dishabituation in sugar-habituated .
PubMed: 38130897
DOI: 10.21769/BioProtoc.4891 -
Learning & Memory (Cold Spring Harbor,... 2001The flexibility of behavior is so rich, and its components are so exquisitely interwoven, that one may be well advised to turn to an isolated behavioral module for... (Review)
Review
The flexibility of behavior is so rich, and its components are so exquisitely interwoven, that one may be well advised to turn to an isolated behavioral module for study. Gill withdrawal in Aplysia, the proboscis extension reflex in the honeybee, and lid closure in mammals are such examples. We have chosen yawing, a single component of flight orientation in Drosophila melanogaster, for this approach. A specialty of this preparation is that the behavioral output can be reduced beyond the single module by one further step. It can be studied in tethered animals in which all turns are blocked while the differentially beating wings still provide the momentum. These intended yaw turns are measured by a torque meter to which the fly is hooked. The fly is held horizontally as if cruising at high speed. The head is glued to the thorax. It can bend its abdomen, extend its proboscis, and move its legs but cannot shift its direction of gaze or its orientation in space. Evidently, a fly hardly ever encounters this bizarre situation in the wild. We describe here the flexibility in this single behavioral variable. It provides insights into the relation between classical and operant conditioning, the processing of and interactions between the conditioned visual stimuli, early visual memory, visual pattern recognition, selective attention, and several other experience-dependent properties of visual orientation behavior. We start with a brief summary of visual flight control at the torque meter.
Topics: Animals; Behavior, Animal; Conditioning, Psychological; Drosophila melanogaster; Flight, Animal; Learning; Memory; Orientation
PubMed: 11160758
DOI: 10.1101/lm.8.1.1