An Alarm Pheromone Modulates Appetitive Olfactory Learning in the Honeybee (Apis Mellifera)

In honeybees, associative learning is embedded in a social context as bees possess a highly complex social organization in which communication among individuals is mediated by dance behavior informing about food sources, and by a high variety of pheromones that maintain the social links between individuals of a hive. Proboscis extension response conditioning is a case of appetitive learning, in which harnessed bees learn to associate odor stimuli with sucrose reward in the laboratory. Despite its recurrent use as a tool for uncovering the behavioral, cellular, and molecular bases underlying associative learning, the question of whether social signals (pheromones) affect appetitive learning has not been addressed in this experimental framework. This situation contrasts with reports underlining that foraging activity of bees is modulated by alarm pheromones released in the presence of a potential danger. Here, we show that appetitive learning is impaired by the sting alarm pheromone (SAP) which, when released by guards, recruits foragers to defend the hive. This effect is mimicked by the main component of SAP, isopentyl acetate, is dose-dependent and lasts up to 24 h. Learning impairment is specific to alarm signal exposure and is independent of the odorant used for conditioning. Our results suggest that learning impairment may be a response to the biological significance of SAP as an alarm signal, which would detract bees from responding to any appetitive stimuli in a situation in which such responses would be of secondary importance

Distinct Transcriptome Expression of the Temporal Cortex of the Primate Microcebus murinus during Brain Aging versus Alzheimer's Disease-Like Pathology

Aging is the primary risk factor of neurodegenerative disorders such as Alzheimer's disease (AD). However, the molecular events occurring during brain aging are extremely complex and still largely unknown. For a better understanding of these age-associated modifications, animal models as close as possible to humans are needed. We thus analyzed the transcriptome of the temporal cortex of the primate Microcebus murinus using human oligonucleotide microarrays (Affymetrix). Gene expression profiles were assessed in the temporal cortex of 6 young adults, 10 healthy old animals and 2 old, “AD-like” animals that presented ß-amyloid plaques and cortical atrophy, which are pathognomonic signs of AD in humans. Gene expression data of the 14,911 genes that were detected in at least 3 samples were analyzed. By SAM (significance analysis of microarrays), we identified 47 genes that discriminated young from healthy old and “AD-like” animals. These findings were confirmed by principal component analysis (PCA). ANOVA of the expression data from the three groups identified 695 genes (including the 47 genes previously identified by SAM and PCA) with significant changes of expression in old and “AD-like” in comparison to young animals. About one third of these genes showed similar changes of expression in healthy aging and in “AD-like” animals, whereas more than two thirds showed opposite changes in these two groups in comparison to young animals. Hierarchical clustering analysis of the 695 markers indicated that each group had distinct expression profiles which characterized each group, especially the “AD-like” group. Functional categorization showed that most of the genes that were up-regulated in healthy old animals and down-regulated in “AD-like” animals belonged to metabolic pathways, particularly protein synthesis. These data suggest the existence of compensatory mechanisms during physiological brain aging that disappear in “AD-like” animals. These results open the way to new exploration of physiological and “AD-like” aging in primates

Desafíos de la caficultura en Centroamérica

Contiene: 1 Trayectoria y viabilidad de las caficulturas centroamericanas (Mario Samper). 2 Aspectos de la sostenibilidad de los sistemas de cultivo de café en América Central (Carlos E. Fernández y Reinhold G. Muschler). 3 Los suelos cafetaleros en América Central y su fertilización (Elemer Bornemisza, Jean Collinet y Alvaro Segura). 4 Hacia un manejo sostenible de la materia orgánica y de la fertilidad biológica de los suelos cafetaleros (Philippe Vaast y Didier Snoeck). 5 El beneficiado ecológico del café (Rolando Vásquez). 6 La roya anaranjada del cafeto: mito y realidad (Jacques Avelino, Raoul Muller, Albertus Eskes, Rodney Santacreo y Francisco Holguín). 7 El ojo de gallo del cafeto (Mycena citricolor) (Amy Wang y Jacques Avelino). 8 La Anthracnosis de los frutos: un grave peligro para la caficultura centroamericana (Raoul A. Müller, Dominique Berry y Daniel Bieysse). 9 La broca de los frutos del cafeto: +la lucha biológica como solución? (Bernard Dufour, Juan Francisco Barrera y Bernard Decazy). 10 Los Nematodos Parásitos del cafeto (Luc Villain, Francisco Anzueto, Adám Hernández y Jean Louis Sarah). 11 Los recursos genéticos: las bases de una solución genética a los problemas de la caficultura latinoamericana (Franéois Anthony, Carlos Astorga y Julien Berthaud). 12 El mejoramiento genético en América Central (Beno¯t Bertrand, Germán Aguilar, Rodney Santacreo y Francisco Anzueto. 13 Aportes de la biotecnología al mejoramiento genético del café: el ejemplo de la multiplicación por embriogénesis somática de híbridos F1 en América Central (Hervé Etienne, Dominique Barry-Etienne, Nelly Vásquez y Marc Berthouly).2 fig. Cuenta con un glosario.Este documento es una recopilación de información realizada por varias autores y autoras. El libro intenta contribuir al debate y desafíos de la investigación cafetalera, presentando los grandes problemas ecológicos, Agronómicos y biológicos que acechan a la caficultura centroamericana, o que la afectarán probablemente en un futuro cercano. El libro comienza por una resena hist6rica que permite tanto entender la diversidad de situaciones de producci6n coma interpretar los debates actuales en un contexto mas amplio de una historia bisecular. Luego, se estudian los principales avances y limitaciones de los sistemas de cultivo con una atención particular del manejo deI suelo con el afán de proponer soluciones, o de identificar campos prioritarios de investigación. También se repasan los grandes desafios deI beneficiado dei café que son principalmente ecológicos. Un gran espacio es dedicado al estudio de las principales enfermedades y plagas deI café, cuyo desarrollo y agravamiento repercute en costos de control muy elevados. La lucha biológica o integrada puede (o podrá) ofrecer soluciones alentadoras. En fin, se presentan las posibilidades de creaci6n de nuevas variedades de café a partir de los recursos genéticos introducidos de Africa, con las esperanzas que despiertan las nuevas biotecnologias

Encoding, consolidation, and retrieval of contextual memory: Differential involvement of dorsal CA3 and CA1 hippocampal subregions

Studies on human and animals shed light on the unique hippocampus contributions to relational memory. However, the particular role of each hippocampal subregion in memory processing is still not clear. Hippocampal computational models and theories have emphasized a unique function in memory for each hippocampal subregion, with the CA3 area acting as an autoassociative memory network and the CA1 area as a critical output structure. In order to understand the respective roles of the CA3- and CA1-hippocampal areas in the formation of contextual memory, we studied the effects of the reversible inactivation by lidocaine of the CA3 or CA1 areas of the dorsal hippocampus on acquisition, consolidation, and retrieval of a contextual fear conditioning. Whereas infusions of lidocaine never impaired elementary tone conditioning, their effects on contextual conditioning provided interesting clues about the role of these two hippocampal regions. They demonstrated first that the CA3 area is necessary for the rapid elaboration of a unified representation of the context. Secondly, they suggested that the CA1 area is rather involved in the consolidation process of contextual memory. Third, they showed that CA1 or CA3 inactivation during retention test has no effect on contextual fear retrieval when a recognition memory procedure is used. In conclusion, our findings point as evidence that CA1 and CA3 subregions of the dorsal hippocampus play important and different roles in the acquisition and consolidation of contextual fear memory, whereas they are not required for context recognition

Effects of the genetic background on cognitive performances of TG2576 mice.

Animal models of genetic diseases obtained by transferring human mutated genes in the mouse are widely used in biomedical based research. They constitute efficient tools to study mechanisms underlying abnormal phenotypes. Unfortunately, the phenotype of the transgene is often obscured by the genetic background of the embryonic stem cells and that of the recipient strain used to create the transgenic line. It is also known, from the literature, that repeatedly backcrossing a transgenic strain to an inbred background may have unfavorable effects that can result in the loss of the transgenic line. In order to analyze the influences of the genetic background on the transgene expression, we studied the effects of the hAPPswe transgene involved in Alzheimer's Amyloid Pathology, in 3 genetic backgrounds differing by their genetic heterogeneity (homozygous vs heterozygous) and the strain of origin (C57BL6, CBA, B6SJL F1) after only one generation backcrossing. Three different behavioral paradigms were used to assess the psychological and cognitive phenotypic differences: elevated plus maze, morris navigation task and contextual fear conditioning. Our data indicate that the best solution to maintain the transgenic line is to backcross repeatedly the transgenic mice into the F1 hybrid cross that was used to create the transgenic strain, whereas phenotyping should be performed comparatively after only one generation backcrossing into various well chosen F1 or inbred backgrounds

Short- and long-term renal outcomes following severe rhabdomyolysis: a French multicenter retrospective study of 387 patients

International audienceBACKGROUND:Rhabdomyolysis is a life-threatening disease that can lead to severe hyperkalemia, acute kidney injury (AKI) and hypovolemic shock. The predictive factors of AKI and acute to chronic kidney disease (CKD) transition remain poorly described.METHODS:This multicenter retrospective study enrolled 387 patients with severe rhabdomyolysis (CPK > 5000 U/L). Primary end-point was the development of severe AKI, defined as stage 2 or 3 of KDIGO classification. Secondary end-points included the incidence of AKI to CKD transition.RESULTS:Among the 387 patients, 315 (81.4%) developed AKI, including 171 (44.1%) with stage 3 AKI and 103 (26.6%) requiring RRT. Stage 2-3 AKI was strongly correlated with serum phosphate, potassium and bicarbonate at admission, as well as myoglobin over 8000 U/L and the need for mechanical ventilation. 42 patients (10.8%) died before day 28. In the 80 patients with available eGFR values both before and 3 months after the rhabdomyolysis, the decrease in eGFR (greater than 20 mL/min/1.73 m2 in 23 patients; 28.8%) was correlated to the severity of the AKI and serum myoglobin levels > 8000 U/L at admission.CONCLUSIONS:Severe rhabdomyolysis leads to AKI in most patients admitted to an ICU. Mechanical ventilation and severity of the rhabdomyolysis, including myoglobin level, are associated with the risk of stage 2-3 AKI. The long-term renal decline is correlated to serum myoglobin at admission