Inhibition of serotonergic signaling induces higher consumption of both sucrose solution and toxic baits in carpenter ants

Biogenic amines play an important role in the regulation of appetitive responses in insects. Among them, serotonin (5-HT) regulates feeding-related processes in numerous insect species. In carpenter ants, 5-HT administration has been shown to depress feeding behavior, thus opening the possibility of using 5-HT modulation in control strategies against those species considered as pest. Here we studied if administration of a 5-HT antagonist, ketanserin, promotes feeding of a sucrose solution and a toxic bait in carpenter ants Camponotus mus. We found that 3 h after a single oral administration of ketanserin, the mass of sucrose solution consumed by carpenter ants increased significantly. A similar effect was found after a chronic administration that lasted 5 days. Yet, ketanserin did neither affect the intake rates nor the activity of the pharyngeal pump that mediates feeding dynamics. In addition, ketanserin promoted the consumption of a toxic bait based on boric acid. Our results thus show that feeding motivation and consumption of both sucrose solution and a toxic bait can be enhanced via prior administration of ketanserin. We discuss the possible mechanisms underlying these effects and conclude that understanding basic physiological and neural principles that underlie feeding motivation allows establishing more efficient control strategies for pest insects.Fil: Josens, Roxana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio del Grupo de Estudio de Insectos Sociales; ArgentinaFil: Giacometti, Alina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio del Grupo de Estudio de Insectos Sociales; ArgentinaFil: Giurfa, Martín. Centre National de la Recherche Scientifique; Francia. Université Paul Sabatier; Francia. Universite de la Mediterranee. Institut Universitaire de France; Franci

Importancia de la información espectral y olfativa en las estrategias de recolección de néctar de la abeja Apis mellífera L.

Fil:Giurfa, Martín. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Latent inhibition in an insect: the role of aminergic signaling

Latent inhibition (LI) is a decrement in learning performance that results from the nonreinforced pre-exposure of the to-beconditioned stimulus, in both vertebrates and invertebrates. In vertebrates, LI development involves dopamine and serotonin; in invertebrates there is yet no information. We studied differential olfactory conditioning of the proboscis extension response in the honeybee Apis mellifera, and we compared LI in individuals treated with antagonists of biogenic amines (dopamine, octopamine, and serotonin). An antagonist of octopamine receptors and two antagonists of serotonin receptors showed LI disruption. We thus provide evidence that serotonin would participate in the regulation of LI in honeybees.Fil: Fernandez, Vanesa Maribel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Giurfa, Martín. Université de Toulouse; Francia. Centre National de la Recherche Scientifique; FranciaFil: Devaud, Jean Marc. Université de Toulouse; Francia. Centre National de la Recherche Scientifique; FranciaFil: Farina, Walter Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentin

Redefining Single-Trial Memories in the Honeybee

Research on honeybee memory has led to a widely accepted model in which a single pairing of an odor stimulus with sucrose induces memories that are independent of protein synthesis but is unable to form protein-synthesis-dependent long-term memory (LTM). The latter is said to arise only after three or more pairings of odor and sucrose. Here, we show that this model underestimates the capacity of the bee brain to form LTMs after a unique appetitive experience. Using state-of-the art conditioning setups and individual-based analyses of conditioned responses, we found that protein-synthesis-dependent memories are formed already 4 h after the single conditioning trial and persist even 3 days later. These memories (4 h, 24 h, and 72 h) exhibit different dependencies on transcription and translation processes. Our results thus modify the traditional view of onetrial memories in an insect with a model status for memory research.Fil: Villar, María Eugenia. Université de Toulouse; Francia. Centre National de la Recherche Scientifique; Francia. Universite de la Mediterranee. Institut Universitaire de France; FranciaFil: Marchal, Paul. Université de Toulouse; Francia. Centre National de la Recherche Scientifique; Francia. Universite de la Mediterranee. Institut Universitaire de France; FranciaFil: Viola, Haydee Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Giurfa, Martín. Université de Toulouse; Francia. Centre National de la Recherche Scientifique; Francia. Fujian Agriculture and Forestry University; Chin

Behavioral tagging underlies memory reconsolidation

Memory reconsolidation occurs when a retrieving event destabilizes transiently a consolidated memory, triggering thereby a new process of restabilization that ensures memory persistence. Although this phenomenon has received wide attention, the effect of new information cooccurring with the reconsolidation process has been less explored. Here we demonstrate that a memory-retrieving event sets a neural tag, which enables the reconsolidation of memory after binding proteins provided by the original or a different contiguous experience. We characterized the specific temporal window during which this association is effective and identified the protein kinase A (PKA) and the extracellular signal-regulated kinase 1 and 2 (ERK 1/2) pathways as the mechanisms related to the setting of the reconsolidation tag and the synthesis of proteins. Our results show, therefore, that memory reconsolidation is mediated by a “behavioral tagging” process, which is common to different memory forms. They represent a significant advance in understanding the fate of memories reconsolidated while being adjacent to other events, and provide a tool for designing noninvasive strategies to attenuate (pathological/traumatic) or improve (education-related) memories.Fil: Rabinovich Orlandi, Iván. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Fullio, Camila Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Schroeder, Matias Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Giurfa, Martín. Centre National de la Recherche Scientifique; FranciaFil: Ballarini, Fabricio Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Moncada, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentin

Inhibitory learning of phototaxis by honey bees in a passive-avoidance task

Honeybees are a standard model for the study of appetitive learning and memory. Yet, fewer attempts have been performedto characterize aversive learning and memory in this insect and uncover its molecular underpinnings. Here, wetook advantage of the positive phototactic behavior of bees kept away from the hive in a dark environment and establisheda passive-avoidance task in which they had to suppress positive phototaxis. Bees placed in a two-compartment box learned toinhibit spontaneous attraction to a compartment illuminated with blue light by associating and entering into that chamberwith shock delivery. Inhibitory learning resulted in an avoidance memory that could be retrieved 24 h after training andthat was specific to the punished blue light. It was mainly operant but involves a Pavlovian component linking the blue lightQ4 and the shock. Coupling and conditioning with transcriptional analyses in key areas of the brain showed that inhibitorylearning of phototaxis leads to an up-regulation of the dopaminergic receptor gene Amdop1 in the calyces of the mushroombodies, consistently with the role of dopamine signaling in different forms of aversive learning in insects. Our results thusintroduce new perspectives for uncovering further cellular and molecular underpinnings of aversive learning and memoryin bees. Overall, they represent an important step toward comparative learning studies between the appetitive and the aversiveframeworks.Fil: Marchal, P.. Centre National de la Recherche Scientifique; FranciaFil: Villar, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Heiyang, Geng. Centre National de la Recherche Scientifique; FranciaFil: Arrufat, Patrick. Centre National de la Recherche Scientifique; FranciaFil: Combe, Maud. Centre National de la Recherche Scientifique; FranciaFil: Viola, Haydee Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Massou, Isabelle. Centre National de la Recherche Scientifique; FranciaFil: Giurfa, Martín. Centre National de la Recherche Scientifique; Franci

Spatial-Memory Formation After Spaced Learning Involves ERKs1/2 Activation Through a Behavioral-Tagging Process

The superiority of spaced over massed learning is an established fact in the formation of long-term memories (LTM). Here we addressed the cellular processes and the temporal demands of this phenomenon using a weak spatial object recognition (wSOR) training, which induces short-term memories (STM) but not LTM. We observed SOR-LTM promotion when two identical wSOR training sessions were spaced by an inter-trial interval (ITI) ranging from 15 min to 7 h, consistently with spaced training. The promoting effect was dependent on neural activity, protein synthesis and ERKs1/2 activity in the hippocampus. Based on the “behavioral tagging” hypothesis, which postulates that learning induces a neural tag that requires proteins to induce LTM formation, we propose that retraining will mainly retag the sites initially labeled by the prior training. Thus, when weak, consecutive training sessions are experienced within an appropriate spacing, the intracellular mechanisms triggered by each session would add, thereby reaching the threshold for protein synthesis required for memory consolidation. Our results suggest in addition that ERKs1/2 kinases play a dual role in SOR-LTM formation after spaced learning, both inducing protein synthesis and setting the SOR learning-tag. Overall, our findings bring new light to the mechanisms underlying the promoting effect of spaced trials on LTM formation.Fil: Tintorelli, Ramiro Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Budriesi, Pablo Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Villar, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Marchal, Paul. Université de Toulouse; FranciaFil: Lopes Da Cunha, Pamela Johanna. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Correa, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Giurfa, Martín. Université de Toulouse, Francia; FranciaFil: Viola, Haydee Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentin

Individual size as determinant of sugar responsiveness in ants

Abstract: Social insects commonly exhibit division of labor in non-reproductive tasks. Task allocation may be related to size, form, and ergonomic differences when workers are anatomically variable. Carpenter ants Camponotus mus collecting nectar exhibit a wide forager size variation, thus raising the question of whether large and minor workers differ in their gustatory responsiveness and specialize, therefore, on different nectar sources. To answer this question, we first established the sucrose concentration at which small and large ants in the laboratory respond appetitively to a sugar solution (sucrose acceptance threshold, SAT) after experiencing a high or a low starvation regime (4- or 1-day carbohydrate deprivation, respectively). Under high starvation, no differences in SATs were found between larger and smaller ants. Under low starvation, both sizes increased their SATs but larger ants had a higher SAT, thus preferring more concentrated solutions while smaller ants responded mostly to more diluted sucrose solutions. In a field assay in which the distribution of larger and smaller ants on sugary food sources was analyzed, small and medium ants were found—in different proportions—at all food sources while larger ants were only found at nectar sources with a higher sugar flow rate, i.e., providing more sugar per unit time. Both field and laboratory assays supported that sugar-related parameters act as determinants of the size distribution of ants among food sources. In addition, interindividual differences in alternative non-sugar-related variables may contribute to this distribution, leading thereby to a potential nectar foraging specialization. Significance statement: Task specialization is crucial for the ecological success of social insects. Carpenter ants allocate individuals of variable size to foraging, thus raising the question of whether they differ in their food preferences. We determined the sugar concentration at which an appetitive response occurs in small and large carpenter ants, and analyzed their distribution on natural and artificial nectar sources in a field assay. Under low starvation, larger ants responded more than smaller ants to higher sucrose concentrations. Coincidently, in the field assay, they were mainly present at sources with higher sucrose delivery. This kind of specialization may reflect the fact that larger ants have larger feeding apparatuses, which may confer a better capacity to deal with the higher viscosity of more concentrated nectars and allow collecting more food at nectaries with higher sugar flow rates. Size specialization may thus increase colony success in the exploitation of variable food sources.Fil: Josens, Roxana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Lopez, M. Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Jofré, Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Giurfa, Martín. Centre National de la Recherche Scientifique; Franci