Sensing and avoiding sick conspecifics requires Gαi2+ vomeronasal neurons

Rodents utilize chemical cues to recognize and avoid other conspecifics infected with pathogens. Infection with pathogens and acute inflammation alter the repertoire and signature of olfactory stimuli emitted by a sick individual. These cues are recognized by healthy conspecifics via the vomeronasal or accessory olfactory system, triggering an innate form of avoidance behavior. However, the molecular identity of the sensory neurons and the higher neural circuits involved in the detection of sick conspecifics remain poorly understood

Gαi2+ vomeronasal neurons govern the initial outcome of an acute social competition

Pheromone detection by the vomeronasal organ (VNO) mediates important social behaviors across different species, including aggression and sexual behavior. However, the relationship between vomeronasal function and social hierarchy has not been analyzed reliably. We evaluated the role of pheromone detection by receptors expressed in the apical layer of the VNO such as vomeronasal type 1 receptors (V1R) in dominance behavior by using a conditional knockout mouse for G protein subunit Gαi2, which is essential for V1R signaling. We used the tube test as a model to analyze the within-a-cage hierarchy in male mice, but also as a paradigm of novel territorial competition in animals from different cages. In absence of prior social experience, Gαi2 deletion promotes winning a novel social competition with an unfamiliar control mouse but had no effect on an established hierarchy in cages with mixed genotypes, both Gαi2−/− and controls. To further dissect social behavior of Gαi2−/− mice, we performed a 3-chamber sociability assay and found that mutants had a slightly altered social investigation. Finally, gene expression analysis in the medial prefrontal cortex (mPFC) for a subset of genes previously linked to social status revealed no differences between group-housed Gαi2−/− and controls. Our results reveal a direct influence of pheromone detection on territorial dominance, indicating that olfactory communication involving apical VNO receptors like V1R is important for the outcome of an initial social competition between two unfamiliar male mice, whereas final social status acquired within a cage remains unaffected. These results support the idea that previous social context is relevant for the development of social hierarchy of a group. Overall, our data identify two context-dependent forms of dominance, acute and chronic, and that pheromone signaling through V1R receptors is involved in the first stages of a social competition but in the long term is not predictive for high social ranks on a hierarchy.Fil: Pallé, Anna. Consejo Superior de Investigaciones Científicas; EspañaFil: Montero, Marta. Consejo Superior de Investigaciones Científicas; EspañaFil: Fernendez, Silvia. Consejo Superior de Investigaciones Científicas; EspañaFil: Tezanos, Patricia. Consejo Superior de Investigaciones Científicas; EspañaFil: De las Heras, Juan. Consejo Superior de Investigaciones Científicas; EspañaFil: Luskey, Valerie. Consejo Superior de Investigaciones Científicas; EspañaFil: Birnbaumer, Lutz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Zufall, Frank. Universitat Saarland; AlemaniaFil: Chamero, Pablo. Centre National de la Recherche Scientifique; FranciaFil: Trejo, José Luis. Consejo Superior de Investigaciones Científicas; Españ

Male-induced early puberty correlates with the maturation of arcuate nucleus kisspeptin neurons in does

In goats, early exposure of spring-born females to sexually active bucks induces an early puberty onset assessed by the first ovulation. This effect is found when females are continuously exposed well before the male breeding season starting in September. The first aim of this study was to evaluate whether a shortened exposure of females to males could also lead to early puberty. We assessed the onset of puberty in Alpine does isolated from bucks (ISOL), exposed to wethers (CAS), exposed to intact bucks from the end of June (INT1), or mid-August (INT2). Intact bucks became sexually active in mid-September. At the beginning of October, 100% of INT1 and 90% of INT2 exposed does ovulated, in contrast to the ISOL (0%) and CAS (20%) groups. This demonstrated that contact with males that become sexually active is the main factor prompting precocious puberty in females. Furthermore, a reduced male exposure during a short window before the breeding season is sufficient to induce this phenomenon. The second aim was to investigate the neuroendocrine changes induced by male exposure. We found a significant increase in kisspeptin immunoreactivity (fiber density and number of cell bodies) in the caudal part of the arcuate nucleus of INT1 and INT2 exposed females. Thus, our results suggest that sensory stimuli from sexually active bucks (e.g., chemosignals) may trigger an early maturation of the ARC kisspeptin neuronal network leading to gonadotropin-releasing hormone secretion and first ovulation

Adaptar-se o morir: Revisió de técniques de Supervised Domain Adaptation per a la classificació d'images

[ES] La adaptación de dominio supervisada (SDA) es una técnica de aprendizaje automático que tiene como objetivo mejorar el rendimiento de los modelos de predicción en situaciones en las que los datos de entrenamiento y los datos de prueba pertenecen a diferentes dominios con tan solo unas pocas muestras del dominio objetivo. En este trabajo se ha desarrollado una comparación de técnicas de Supervised Domain Adaptation, con el objetivo de identificar cuáles son las más efectivas en la resolución del problema de la clasificación de imagen en situaciones en las que los datos de entrenamiento y los datos de prueba pertenecen a diferentes dominios, construyendo un benchmark con condiciones equiparables. Además, se presenta CCeSAR, un método nuevo que se construye sobre CCSA, una de las técnicas de Supervised Domain Adaptation comparadas. Nuestro método incorpora aprendizaje autosupervisado de clasificación de rotaciones como tarea secundaria para tratar de conseguir una mejor adaptación al dominio objetivo.[EN] Supervised domain adaptation (SDA) is a Machine Learning technique that aims to improve the performance of prediction models in situations where the training data and test data belong to different domains with only a few samples from the target domain. In this work, a comparison of Supervised Domain Adaptation techniques has been developed with the aim of identifying which are the most effective in solving the image classification problem in situations where the training data and the test data belong to different domains, building a benchmark with comparable conditions. In addition, CCeSAR, a new method that builds on CCSA, one of the compared Supervised Domain Adaptation techniques, is presented. Our method incorporates self-supervised learning of rotations classification as a secondary task to try to achieve a better adaptation to the target domain.Baggetto Chamero, JP. (2023). Adaptarse o morir: Revisión de técnicas de Supervised Domain Adaptation para clasificación de imágenes. Universitat Politècnica de València. http://hdl.handle.net/10251/19779

Olfactory subsystems in mammals: morphology, genetic and evolution

The nasal cavity and the elements it comprises are lined by mucosa. This mucosa contains olfactory sensory neurons, which are organized into four different territories: main olfactory epithelium, septal organ, vomeronasal epithelium and ganglion of Grünemberg. From a morphological point of view, these territories could initially be considered as isolated olfactory subsystems, which - as a whole or independently - have been addressed in the contributions enclosed in this Topic

Estudi i traducció automàtica d'una llengua amb recursos limitats

[EN] The problem of machine translation is particularly interesting in those languages for which, due to population, political relevance, isolation or other reasons, the amount of available resources is limited, where resources usually mean existing translations from or into any other language with a more advantageous situation. This problem is of current interest given that countries in these circumstances belong to international institutions where machine translation is proposed as a solution to multilateral meetings. It is a particularly important problem in the current paradigm, since the state of the art is constituted by statistical models that require large volumes of data to learn the underlying patterns of the language. In this TFG we propose to consider an artificial language, formally proposed in 2014, Toki Pona as a testbed that addresses the above problem. This minimalist language seeks to express the maximum number of meanings with minimal complexity. While Toki Pona is not intended, unlike Esperanto, as a language for international communication, it does share with it features such as simplicity of learning. Since its informal presentation on the web in 2001, the Toki Pona community has grown in number and activity, and there are resources with translations generated by it that will be used as a basis for learning a neural network for automatic translation. These resources are endorsed by the community so they can be considered reliable data in a machine learning process. An experimentation will obtain the results that will allow conclusions and possible lines of work to be drawn. In addition, the TFG proposes the design of a formal grammar, not existing so far, which will allow future studies using techniques other than neural network learning.[ES] El problema de la traducción automática es particularmente interesante en aquellos idiomas para los que, por cuestiones de población, relevancia política, aislamiento u otros motivos, la cantidad de recursos disponibles son limitados, donde por recursos habitualmente se entienden traducciones existentes de, o desde, el idioma a cualquier otro con situación más ventajosa. Actualmente, este problema es de interés dado que países en estas circunstancias pertenecen a instituciones internacionales donde se plantea la traducción automática como solución a las reuniones multilaterales. Es un problema especialmente importante en el paradigma actual, ya que el estado del arte lo constituyen modelos estadísticos que necesitan de grandes volúmenes de datos para poder aprender los patrones subyacentes del lenguaje. En este TFG se plantea considerar un idioma artificial, propuesto formalmente en 2014, el Toki Pona como banco de prueba que aborde el problema anteriormente expuesto. Este idioma minimalista busca expresar el máximo de significados con una complejidad mínima. Si bien Toki Pona no se plantea, al contrario del Esperanto, como una lengua de comunicación internacional, sí comparte con él características como la sencillez de aprendizaje. Desde su presentación informal en la web en 2001, la comunidad Toki Pona ha crecido en número y actividad, existiendo recursos con traducciones generados por esta que se utilizarán como base para el aprendizaje de una red neuronal para la traducción automática. Estos recursos están avalados por la comunidad por lo que pueden considerarse datos fiables en un proceso de aprendizaje automático. Una experimentación obtendrá los resultados que permitan obtener conclusiones y posibles lineas de trabajo. Además, el TFG plantea el diseño de una gramática formal, no existente hasta el momento, que permita estudios futuros utilizando técnicas distintas al aprendizaje de redes neuronales.[CA] El problema de la traducció automàtica és particularment interessant en aquells idiomes per als quals, per qüestions de població, rellevància política, aïllament o altres motius, la quantitat de recursos disponibles són limitats, on per recursos habitualment s’entenen traduccions existents de, o des de, l’idioma a qualsevol altre amb una situació més avantatjosa. Actualment, aquest problema és interessant perquè països en aquestes circumstàncies pertanyen a institucions internacionals on es planteja la traducció automàtica com a solució a les reunions multilaterals. És un problema especialment important al paradigma actual, ja que l’estat de l’art el constitueixen models estadístics que necessiten grans volums de dades per poder aprendre els patrons subjacents del llenguatge. En aquest TFG es planteja considerar un idioma artificial, proposat formalment el 2014, el Toki Pona com a banc de prova que abordi el problema anteriorment exposat. Aquest idioma minimalista cerca expressar el màxim de significats amb una complexitat mínima. Si bé Toki Pona no es planteja, al contrari de l’esperanto, com una llengua de comunicació internacional, sí que comparteix amb ell característiques com la senzillesa d’aprenentatge. Des de la seva presentació informal a la web el 2001, la comunitat Toki Pona ha crescut en nombre i activitat, i hi ha recursos amb traduccions generats per aquesta que s’utilitzaran com a base per a l’aprenentatge d’una xarxa neuronal per a la traducció automàtica. Aquests recursos estan avalats per la comunitat, per la qual cosa es poden considerar dades fiables en un procés d’aprenentatge automàtic. Una experimentació obtindrà els resultats que permetin obtenir conclusions i possibles línies de treball. A més, el TFG planteja el disseny d’una gramàtica formal, no existent fins ara, que permeti estudis futurs utilitzant tècniques diferents de l’aprenentatge de xarxes neuronals.Baggetto Chamero, JP. (2022). Study and automatic translation of a language with limited resources. Universitat Politècnica de València. http://hdl.handle.net/10251/185062TFG

Is the Loss of Trpc2 Gene Function a Real Working Hypothesis for the Emergence of Same-Sex Sexual Behavior in Old World Primates?

International audienc

Dampening of cytosolic Ca2+ oscillations on propagation to nucleus

El pdf del artículo es el manuscrito de autor.Ca2+ signals may regulate gene expression. The increase of the cytosolic Ca2+ concentration ([Ca2+]c) promotes activation and/or nuclear import of some transcription factors, but others require the increase of the nuclear Ca2+ concentration ([Ca2+]N) for activation. Whether the nuclear envelope may act as a diffusion barrier for propagation of [Ca2+]c signals remains controversial. We have studied the spreading of Ca2+ from the cytosol to the nucleus by comparing the cytosolic and the nuclear Ca2+ signals reported by targeted aequorins in adrenal chromaffin, PC12, and GH3 pituitary cells. Strong stimulation of either Ca2+ entry (by depolarization with high K+ or acethylcholine) or Ca2+ release from the intracellular Ca2+ stores (by stimulation with caffeine, UTP, bradykinin, or thyrotropin-releasing hormone (TRH)) produced similar Ca2+ signals in cytosol and nucleus. In contrast, both spontaneous and TRH-stimulated oscillations of cytosolic Ca2+ in single GH3 cells were considerably dampened during propagation to the nucleus. These results are consistent with the existence of a kinetic barrier that filters high frequency physiological [Ca2+]c oscillations without disturbing sustained [Ca2+]c increases. Thus, encoding of the Ca2+ signal may allow differential control of Ca2+-dependent mechanisms located at either the cytosol or the nucleus.This work was supported by a grant from the Spanish Ministerio de Ciencia y Tecnología (MCyT; BFI2001-2073).Peer Reviewe