Involvement of Noradrenergic Neurotransmission in the Stress- but not Cocaine-Induced Reinstatement of Extinguished Cocaine-Induced Conditioned Place Preference in Mice: Role for β-2 Adrenergic Receptors

The responsiveness of central noradrenergic systems to stressors and cocaine poses norepinephrine as a potential common mechanism through which drug re-exposure and stressful stimuli promote relapse. This study investigated the role of noradrenergic systems in the reinstatement of extinguished cocaine-induced conditioned place preference by cocaine and stress in male C57BL/6 mice. Cocaine- (15 mg/kg, i.p.) induced conditioned place preference was extinguished by repeated exposure to the apparatus in the absence of drug and reestablished by a cocaine challenge (15 mg/kg), exposure to a stressor (6-min forced swim (FS); 20–25°C water), or administration of the α-2 adrenergic receptor (AR) antagonists yohimbine (2 mg/kg, i.p.) or BRL44408 (5, 10 mg/kg, i.p.). To investigate the role of ARs, mice were administered the nonselective β-AR antagonist, propranolol (5, 10 mg/kg, i.p.), the α-1 AR antagonist, prazosin (1, 2 mg/kg, i.p.), or the α-2 AR agonist, clonidine (0.03, 0.3 mg/kg, i.p.) before reinstatement testing. Clonidine, prazosin, and propranolol failed to block cocaine-induced reinstatement. The low (0.03 mg/kg) but not high (0.3 mg/kg) clonidine dose fully blocked FS-induced reinstatement but not reinstatement by yohimbine. Propranolol, but not prazosin, blocked reinstatement by both yohimbine and FS, suggesting the involvement of β-ARs. The β-2 AR antagonist ICI-118551 (1 mg/kg, i.p.), but not the β-1 AR antagonist betaxolol (10 mg/kg, i.p.), also blocked FS-induced reinstatement. These findings suggest that stress-induced reinstatement requires noradrenergic signaling through β-2 ARs and that cocaine-induced reinstatement does not require AR activation, even though stimulation of central noradrenergic neurotransmission is sufficient to reinstate

Rethinking recognition: social context in adult life rather than early experience shapes recognition in a social wasp

Social recognition represents the foundation of social living. To what extent social recognition is hard-wired by early-life experience or flexible and influenced by social context of later life stages is a crucial question in animal behaviour studies. Social insects have represented classic models to investigate the subject, and the acknowledged idea is that relevant information to create the referent template for nest-mate recognition (NMR) is usually acquired during an early sensitive period in adult life. Experimental evidence, however, highlighted that other processes may also be at work in creating the template and that such a template may be updated during adult life according to social requirements. However, currently, we lack an ad hoc experiment testing the alternative hypotheses at the basis of NMR ontogeny in social insects. Thus, to investigate the mechanisms underlying the ontogeny of NMR in Polistes wasps, a model genus in recognition studies, and their different role in determining recognition abilities, we subjected Polistes dominula workers to different olfactory experiences in different phases of their life before inserting them into the social environment of a novel colony and testing them in recognition bioassays. Our results show that workers develop their NMR abilities based on their social context rather than through pre-imaginal and early learning or self-referencing. Our study demonstrates that the social context represents the major component shaping recognition abilities in a social wasp, therefore shedding new light on the ontogeny of recognition in paper wasps and prompting the reader to rethink about the traditional knowledge at the basis of the recognition in social insects. This article is part of the theme issue 'Signal detection theory in recognition systems: from evolving models to experimental tests'

Behavioural and neurogenomic responses of host workers to social parasite invasion in a social insect

The strong coevolutionary arms race between social parasites and their hosts has dramatically shaped the life-history traits of both parties. One of the main strategies exhibited by hosts in response to parasitism is reproduction by host workers. We lack a mechanistic understanding of how these defence strategies unfold and, specifically, whether hosts exhibit more subtle strategies to reduce the costs of parasitism from the outset. Here we test the hypothesis that there are both behavioural and neurogenomic signatures of worker responses to parasitism, prior to overt expression in the form of egg-laying; we test this using the social parasite—social host system of the paper wasps Polistes sulcifer-Polistes dominula. We characterized individual workers’ position within the social interaction network of queenright and host colonies immediately after parasite usurpation, weeks before the workers’ reproductive rebellion is evident. Parasitism influenced network centrality measures, with workers in parasitized colonies showing increased connectedness and centrality compared to those in unparasitized ones. Next, we quantified brain gene expression levels for five genes related to physiological and behavioural phenotypes in Polistes wasps. The gene Imaginal disc growth factor (Idgf4), thought to be responsive to changes in the social environment, was significantly down-regulated in workers from parasitized colonies; this may be an indication that parasitized workers are anticipating a shift toward a less worker-like phenotype in preparation for their reproductive rebellion. Our results provide the first evidence of early behavioural and neurogenomic responses of host workers toward the presence of an inquiline social parasite in a social insect

Hornets and Honey Bees: A Coevolutionary Arms Race between Ancient Adaptations and New Invasive Threats

Hornets and honey bees have a long history of coevolution resulting in a plethora of captivating adaptations and counteradaptations between predator and prey. From simple physiological mechanisms to complex behavioral strategies, some Vespa hornets have specialized in hunting honey bees, while the latter have put in place effective defenses to counteract their attack. Both hornets and honey bees have evolved the ability to detect the odors and the pheromones emitted by the other to locate the prey or to spot foraging predators. Hornets often rely on their bigger size, heavily armored body and destructive attacks, while honey bees differentiated collective defense responses finely coordinated to deter or kill the hornet menace. However, when new species of hornets and honey bees come into contact, the absence of coevolution can have a heavy impact on the defenseless bees. The evolutionary arms race between hornets and honey bees provides not only compelling examples of adaptations and counteradaptations between predator and prey, but could also represent a starting point for the development of effective and sustainable strategies to protect honey bees and beekeeping activities and to control invasive alien species of hornets

Technician components and requirements model for the formation and management of cooperation networks among civil construction companies

A indústria da Construção Civil possui um modo de operação semelhante ao das organizações virtuais, mas de forma não estruturada, deixando de proporcionar vantagens competitivas. Para tanto, o artigo propõe um Modelo de Requisitos e Componentes Técnicos, baseado na metodologia EKD (Enterprise Knwoledge Development), para auxiliar a formação e gerência de redes entre empresas da construção civil. Para a elaboração do modelo proposto, foi conduzida uma análise dos projetos internacionais mais relevantes no setor da construção além de estudo de casos contendo sete obras a fim de detectar seus objetivos e pontos falhos a serem reestruturados e adaptados para a indústria da construção civil brasileira. Não obstante, o modelo proposto baseou-se em uma adaptação das melhores práticas de uma arquitetura de referência para redes. Como resultado, a proposição viabiliza uma visão clara dos requisitos necessários, explora a necessidade de intensa comunicação e troca de informações, além de contribuir com pesquisas futuras no que tange a um futuro desenvolvimento de sistema de informação direcionado para este segmento econômico.The operational method of civil construction can be analyzed by the outlook of virtual organizations, however not yet structuralized, hence not providing competitive advantages. Thus, this article considers a Technical Components and Requirements Model, based on EKD methodology (Enterprise Knowledge Development), to assist in the formation and management of networks in civil construction companies. For the elaboration of the considered model, an analysis of the most important international construction projects was conducted, in addition to a case study from seven construction projects in order to detect their goals and defective points, to then be reorganized and adapted to the Brazilian civil construction industry. Moreover, the considered model was also based on an adaptation of reference architecture for civil construction networks. As a result, the proposal makes possible, to the stakeholders, a clear view of the necessary requirements, exploring the necessity of intense communication and exchange of information, besides contributing to future research works regarding a future development of an information system directed for this economic segment

Differential investment in visual and olfactory brain regions is linked to the sensory needs of a wasp social parasite and its host

Obligate insect social parasites evolve traits to effectively locate and then exploit their hosts, whereas hosts have complex social behavioral repertoires, which include sensory recognition to reject potential conspecific intruders and heterospecific parasites. While social parasites and host behaviors have been studied extensively, less is known about how their sensory systems function to meet their specific selective pressures. Here, we compare investment in visual and olfactory brain regions in the paper wasp Polistes dominula, and its obligate social parasite P. sulcifer, to explore the links among sensory systems,brain and behavior. Our results show significant relative volumetric differences between these two closely related species, consistent with their very different life histories. Social parasites show proportionally larger optic lobes and central complex to likely navigate long-distance migrations and unfamiliar landscapes to locate the specific species of hosts they usurp. Contrastingly, hosts have larger antennal lobes and calyces of the mushroom bodies compared with social parasites, as predicted by their sensory means to maintain social cohesion via olfactory signals, allocate colony tasks, forage, and recognize conspecific and heterospecific intruders. Our work suggests how this tradeoff between visual and olfactory brain regions may facilitate different sensory adaptations needed to perform social and foraging tasks by the host, including recognition of parasites, or to fly long distances and successful host localizing by the social parasite

Gut microbial composition in different castes and developmental stages of the invasive hornet Vespa velutina nigrithorax

Social insects are successful animal invaders. Their survival and success, and in some cases also their impact on invaded ecosystem functioning, is often mediated by symbiosis with microorganisms. Here, we report a comprehensive comparative characterization of the gut microbial communities of different castes and developmental stages of the invasive hornet Vespa velutina nigrithorax. The species recently colonized Europe, becoming a high ecological and economic concern, as it threatens pollinator survival and competes with native hornet species. We used targeted meta-genomics to describe the yeasts and bacteria gut communities of individuals of different reproductive phenotypes (workers and future queens), life stages (larvae, newly emerged individuals and adults) and colony non-living samples (nest paper and larval faeces). Bacilli, Gammaproteobacteria, Actinobacteria, Alphaproteobacteria were the most abundant classes of bacteria, and Saccharomycetes, Dothideomycetes, Tremellomycetes and Eurotiomycetes were the most represented yeast classes. We found that the microbial compositions significantly differ across developmental stages and castes, with yeast and bacterial communities switching in frequency and abundance during ontogeny and according to reproductive phenotype. Moreover, the gut microbial communities poorly mirror those found in the nest, suggesting that hornets possess a specific microbial signature. Our results provide the first metagenomic resource of the microbiome of V. velutina in Europe and suggest the importance of considering life stages, reproductive phenotypes and nest influence in order to obtain a comprehensive picture of social insect microbial communities