The diverse roles of insulin signaling in insect behavior

Frontiers in Insect Science, Journal Year: 2024, Volume and Issue: 4

Published: April 4, 2024

In insects and other animals, nutrition-mediated behaviors are modulated by communication between the brain peripheral systems, a process that relies heavily on insulin/insulin-like growth factor signaling pathway (IIS). Previous studies have focused mechanistic physiological functions of insulin-like peptides (ILPs) in critical developmental adult milestones like pupation or vitellogenesis. Less work has detailed mechanisms connecting ILPs to nutrient-mediated related survival reproductive success. Here we briefly review range linked IIS insects, from conserved regulation feeding behavior evolutionarily derived polyphenisms. Where possible, incorporate information Drosophila melanogaster model species describe molecular neural connect nutritional status behavioral expression via IIS. We identify knowledge gaps which include diverse functional roles ILPs, how modulate function across lifespan, lack research broad taxa. Addressing these would enable better understanding evolution this widely deployed tool kit pathway.

Language: Английский

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Invertebrates as models of learning and memory: investigating neural and molecular mechanisms

Journal of Experimental Biology, Journal Year: 2023, Volume and Issue: 226(3)

Published: Jan. 31, 2023

In this Commentary, we shed light on the use of invertebrates as model organisms for understanding causal and conserved mechanisms learning memory. We provide a condensed chronicle contribution offered by mollusks to studies how where nervous system encodes stores memory describe rich cognitive capabilities some insect species, including attention concept learning. also discuss planarians investigating dynamics during brain regeneration highlight role stressful stimuli in forming memories. Furthermore, focus increasing evidence that display forms emotions, which provides new opportunities unveiling neural molecular underlying complex interaction between stress, emotions cognition. doing so, experimental challenges suggest future directions expect field take coming years, particularly regarding what we, humans, need know preventing and/or delaying loss. This article has an associated ECR Spotlight interview with Veronica Rivi.

Language: Английский

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Identification of Putative Molecules for Adiponectin and Adiponectin Receptor and Their Roles in Learning and Memory in Lymnaea stagnalis

Biology, Journal Year: 2023, Volume and Issue: 12(3), P. 375 - 375

Published: Feb. 27, 2023

Adiponectin enhances insulin sensitivity, which improves cognition in mammals. How adiponectin affects the mechanism's underlying cognition, however, remains unknown. We hypothesized that experiments using pond snail Lymnaea stagnalis, has long been used learning and memory studies function of insulin-like peptides affect memory, could clarify basic mechanisms by cognition. first identified putative molecules its receptor Lymnaea. then examined their distribution central nervous system changes expression levels when hemolymph glucose concentrations were intentionally decreased food deprivation. also applied an operant conditioning protocol escape behavior to how changed after conditioned was established. The results demonstrate adiponectin's increased association with a reduced concentration both peptide receptors Thus, involvement adiponectin-signaling cascade suggested occur via activation insulin.

Language: Английский

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Studies on a widely-recognized snail model species (Lymnaea stagnalis) provide further evidence that vertebrate steroids do not have a hormonal role in the reproduction of mollusks

Frontiers in Endocrinology, Journal Year: 2022, Volume and Issue: 13

Published: Sept. 8, 2022

Experiments were carried out to determine whether, as with other mollusks that have been studied, the snail, Lymnaea stagnalis , can absorb, esterify and store vertebrate steroids are present in water. We also experiments whether neural tissues of snail could be immunohistochemically stained an antibody human aromatase (a key enzyme catalyzes conversion testosterone [T] 17β-estradiol [E 2 ]); and, if so, significance such staining. Previous studies on reported staining proposed this decisive evidence same steroid synthesis pathway vertebrates. found snails retain esterified T, E progesterone ethinyl-estradiol (albeit absorption rate about four times slower, a weight basis, than mussel, Mytilus edulis ). not only anti-human aromatase, but nuclear receptor (nPR) gonadotropin-releasing hormone antibodies cells. However, further experiments, involving gel electrophoretic separation, followed by immunostaining, proteins extracted from tissue, at least two positively-stained bands for each antibody, none which had masses matching raised. The anti-aromatase even 140 kDA ladder protein used molecular marker gels. Mass spectrometric analysis did find any peptide sequences corresponded proteins. Our findings confirm presence vertebrate-like sex molluscan is necessarily endogenous origin. results show immunohistochemical using against grossly non-specific likely little or no value studying activity mollusks. conclusions consistent fact genes nPR genome mollusk. overarching conclusion, our previous studies, endocrinology humans vertebrates continuing carry physiological ecotoxicological basis false assumption, unconscionable waste resources.

Language: Английский

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Genes Upregulated by Operant Conditioning of Escape Behavior in the Pond Snail Lymnaea stagnalis

ZOOLOGICAL SCIENCE, Journal Year: 2023, Volume and Issue: 40(5)

Published: July 18, 2023

The pond snail Lymnaea stagnalis is capable of learning by both classical conditioning and operant conditioning. Although related to escape behavior with punishment has been examined some research groups, the molecular mechanisms are not known. In present study, we changes in expression levels cAMP-response element binding protein 1 (CREB1), CREB2, CREB-binding (CBP), monoamine oxidase (MAO) central nervous system (CNS) using real-time PCR following behavior. CREB1 CREB2 transcription factors involved long-term memory Lymnaea; CBP a coactivator CREB1; MAO degrading enzyme for monoamines (e.g., serotonin) important roles Lymnaea. conditioning, cohort, which snails escaping from container encountered aversive KCl, exhibited significantly fewer attempts than control distilled water, during training test periods. After were upregulated, ratio CREB1/CREB2 was also increased, suggesting that involves these factors. content such as serotonin CNS decreased. upregulated genes identified study will help further elucidate

Language: Английский

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Expression Level Changes in Serotonin Transporter are Associated with Food Deprivation in the Pond Snail Lymnaea stagnalis

ZOOLOGICAL SCIENCE, Journal Year: 2023, Volume and Issue: 40(5)

Published: Aug. 22, 2023

In the pond snail Lymnaea stagnalis, serotonin (5-HT) plays an important role in feeding behavior and its associated learning (e.g., conditioned taste aversion: CTA). The 5-HT content central nervous system (CNS) fluctuates with changes nutritional status, but it is also expected to be influenced by transporter (SERT) expression level. present study, we identified SERT observed localization 5-HTergic neurons, including cerebral giant cells (CGCs) ganglia pedal A cluster neurons right left dorsal 1 situ hybridization. Real-time PCR revealed that mRNA level was lower under severe food deprivation than mild whole CNS as well a single CGC. These results inversely correlated previous data higher severely food-deprived state mildly state. Furthermore, CGCs, significantly increased compared Our findings suggest may affect signaling, probably contributing memory mechanisms Lymnaea.

Language: Английский

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Insulin Signaling Pathway Mediates FoxO–Pepck Axis Regulation of Glucose Homeostasis in Drosophila suzukii

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(19), P. 10441 - 10441

Published: Sept. 27, 2024

The agricultural pest Drosophila suzukii exhibits a strong preference for feeding on fresh fruits, demonstrating high adaptability to sugary environments. Meanwhile, sugar levels stimulate insulin secretion, thereby regulating the steady state of metabolism. Understanding mechanisms related metabolism in D. is crucial due its adaptation these specific environmental conditions. signaling pathway an evolutionarily conserved phosphorylation cascade with significant roles development and We observed that activation inhibited FoxO activity downregulated expression Pepck, activating glycolysis reducing glucose levels. By contrast, inhibiting increased upregulated which activated gluconeogenesis led Our findings demonstrated role mediating through FoxO–Pepck axis, supports ecological high-sugar niches, providing insights into metabolic control suggesting potential strategies management. Elucidating molecular processes important understanding regulation specialization suzukii.

Language: Английский

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Octopamine integrates the status of internal energy supply into the formation of food-related memories

eLife, Journal Year: 2024, Volume and Issue: 12

Published: April 24, 2024

The brain regulates food intake in response to internal energy demands and availability. However, can storage influence the type of memory that is formed? We show duration starvation determines whether Drosophila melanogaster forms appetitive short-term or longer-lasting intermediate memories. glycogen muscles adipose tissue influences how intensely sucrose-associated information stored. Insulin-like signaling octopaminergic reward neurons integrates into formation. Octopamine, turn, suppresses formation long-term memory. Octopamine not required for because octopamine-deficient mutants form sucrose other nutrients depending on status. reduced positive reinforcing effect at high levels, combined with increased stability food-related memories due prolonged periods starvation, could lead intake.

Language: Английский

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Intense Locomotion Enhances Oviposition in the Freshwater Mollusc Lymnaea stagnalis: Cellular and Molecular Correlates

Biology, Journal Year: 2023, Volume and Issue: 12(6), P. 764 - 764

Published: May 24, 2023

Intense species-specific locomotion changes the behavioural and cognitive states of various vertebrates invertebrates. However, whether how reproductive behaviour is affected by previous increased motor activity remains largely unknown. We addressed this question using a model organism, pond snail Lymnaea stagnalis. crawling in shallow water for two hours had previously been shown to affect orienting new environment as well state serotonergic system L. found that same resulted an number egg clutches total eggs laid following 24 h. per clutch was not affected. This effect significantly stronger from January May, contrast September-December period. Transcripts egg-laying prohormone gene tryptophan hydroxylase gene, which codes rate-limiting enzyme serotonin synthesis, were higher central nervous snails rested clean after intense crawling. Additionally, neurons left (but right) caudo-dorsal cluster (CDC), produce ovulation hormone play key role oviposition, responded stimulation with spikes, although there no differences their resting membrane potentials. speculate left-right asymmetry response due asymmetric (right) location male having antagonistic influence on female hormonal hermaphrodite mollusc. Serotonin, known enhance oviposition stagnalis, direct potential or electrical CDC neurons. Our data suggest (i) two-hour enhances (ii) depends season, (iii) underlying mechanisms may include excitability expression gene.

Language: Английский

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FOXO in Lymnaea: Its Probable Involvement in Memory Consolidation

Biology, Journal Year: 2023, Volume and Issue: 12(9), P. 1201 - 1201

Published: Sept. 1, 2023

Food deprivation activates forkhead box O (FOXO), a transcription factor downstream of insulin receptors. In the pond snail Lymnaea stagnalis, signaling and food improve memory consolidation following conditioned taste aversion (CTA) learning. We investigated subcellular localization FOXO in changes its expression levels deprivation, CTA learning, administration. Immunohistochemistry revealed that (LymFOXO) was located central nervous system (CNS) neuronal cytoplasm food-satiated snails but mainly nuclei food-deprived snails. Following acquisition, LymFOXO translocated to remained Contrary our expectations, administered CNS did not induce translocation into Real-time PCR used quantify mRNA levels, target genes, pathway genes upregulated compared Insulin applied isolated CNSs from increased vehicle-treated samples. prepares function nucleus enhances learning application directly affect protein localization. Thus, administration may stimulate pathways other than cascade.

Language: Английский

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