Re-wiring of the bonded brain: Gene expression among pair bonded female prairie voles changes as they transition to motherhood.

Motherhood is a costly life-history transition accompanied by behavioral and neural plasticity necessary for offspring care. Motherhood in the monogamous prairie vole is associated with decreased pair bond strength, suggesting a trade-off between parental investment and pair bond maintenance. Neural mechanisms governing pair bonds and maternal bonds overlap, creating possible competition between the two. We measured mRNA expression of genes encoding receptors for oxytocin (oxtr), dopamine (d1r and d2r), mu-opioids (oprm1a), and kappa-opioids (oprk1a) within three brain areas processing salience of sociosensory cues (anterior cingulate cortex; ACC), pair bonding (nucleus accumbens; NAc), and maternal care (medial preoptic area; MPOA). We compared gene expression differences between pair bonded prairie voles that were never pregnant, pregnant (~day 16 of pregnancy), and recent mothers (day 3 of lactation). We found greater gene expression in the NAc (oxtr, d2r, oprm1a, and oprk1a) and MPOA (oxtr, d1r, d2r, oprm1a, and oprk1a) following the transition to motherhood. Expression for all five genes in the ACC was greatest for females that had been bonded for longer. Gene expression within each region was highly correlated, indicating that oxytocin, dopamine, and opioids comprise a complimentary gene network for social signaling. ACC-NAc gene expression correlations indicated that being a mother (oxtr and d1r) or maintaining long-term pair bonds (oprm1a) relies on the coordination of different signaling systems within the same circuit. Our study suggests the maternal brain undergoes changes that prepare females to face the trade-off associated with increased emotional investment in offspring, while also maintaining a pair bond.

Bonding against the odds: Male prairie vole response to the "widow effect" among females.

Although pair bonding is the preferred mating tactic among socially monogamous prairie voles, naturalistic observations have demonstrated many males remain non-bonded. Moreover, although males readily re-bond after the loss of a partner, females do not (i.e., the "widow effect'). Few studies have attempted to address why so many males remain non-bonded or if a reluctance of re-bonding in females contributes to this outcome. We investigate how female bonding history impacts male pair bond formation. Specifically, we test two alternative hypotheses for how sexually naïve males will behave when paired with widow females. The fecundity hypothesis predicts males will avoid bonding with widow females and be more receptive to novel bond-naïve females. The preference to bond hypothesis predicts males will choose to bond and express a partner preference, irrespective of if a pair-mate is a widow or sexually naïve. Our results demonstrated that males expressed a partner preference for females regardless of their social history. These data support the preference to bond hypothesis and suggest natural variation in bonding may not be strongly due to males forgoing bonding opportunities.

Motherhood and DREADD manipulation of the nucleus accumbens weaken established pair bonds in female prairie voles.

Monogamous pair bonding has evolved to enhance reproductive success and ensure offspring survival. Although the behavioral and neural mechanisms regulating the formation of pair bonds have been relatively well outlined, how these relationships are regulated and maintained across the lifetime of an individual remains relatively unexplored. One way to explore this is to study the maintenance of a social bond across a major life-history transition. The transition to motherhood is among the most poignant moments in the life history of a female, and is associated with significant neural and behavioral changes and shifting priorities. The nucleus accumbens (NAc) is known to modulate social valence and is central to mammalian pair bonding. In this study, we investigated two mechanisms driving variation in bond strength in the socially monogamous prairie vole (Microtus ochrogaster). We manipulated neural activity of the NAc at two distinct stages of life-history, before and after the birth of offspring, to assess how neural activity and social contexts modulate female pair bond strength. Our results showed DREADD (Designer Receptor Exclusively Activated by Designer Drugs) inhibition of the NAc decreases affiliative behavior towards the mating partner, whereas DREADD activation of the NAc increases affiliative behavior of strangers, thereby decreasing social selectivity. We also found a robust "birth effect" on pair bond strength, such that bonds with partners were weakened after the birth of offspring, an effect not attributable to the amount of cohabitation time with a partner. Overall, our data support the hypotheses that NAc activity modulates reward/saliency within the social brain in different ways, and that motherhood comes with a cost for the bond strength between mating partners.

Multi-Level Effects Driving Cognitive and Behavioral Variability among Prairie Voles: Insights into Reproductive Decision-Making from Biological Levels of Organization.

Behavioral phenotypes play an active role in maximizing fitness and shaping the evolutionary trajectory of species by offsetting the ecological and social environmental factors individuals experience. How these phenotypes evolve and how they are expressed is still a major question in ethology today. In recent years, an increased focus on the mechanisms that regulate the interactions between an individual and its environment has offered novel insights into the expression of alternative phenotypes. In this review, we explore the proximate mechanisms driving the expression of alternative reproductive phenotypes in the male prairie vole (Microtus ochrogaster) as one example of how the interaction of an individual's social context and internal milieu has the potential to alter behavior, cognition, and reproductive decision-making. Ultimately, integrating the physiological and psychological mechanisms of behavior advances understanding into how variation in behavior arises. We take a "levels of biological organization" approach, with prime focus placed on the level of the organism to discuss how cognitive processes emerge as traits, and how they can be studied as important mechanisms driving the expression of behavior.

[Hypertrophic septal cardiomyopathy, the great simulator]. / Miocardiopatía hipertrófica septal, la gran simuladora.

Hypertrophic cardiomyopathy is the more commonly (60 to 70 percent) genetically determined disease of the heart muscle caused by mutations in one of several sarcomere genes that encode components of the heart's contractile apparatus. It is characterized by disproportionate hypertrophy in the absence of a secondary cause. The clinical presentation is variable, ranging from asymptomatic to heart failure or sudden cardiac death. Hypertrophy and abnormal ventricular configuration can result in dynamic left ventricular outflow obstruction in most cases. The goal of therapeutic interventions is largely to reduce dynamic obstruction, with different therapeutic options encompassing risk stratification for sudden death, genetic screening, lifestyle modifications, and drugs. A case of hypertrophic septal cardiomyopathy, a fairly frequent and under-diagnosed entity, is discussed below.

Divergent neurogenomic responses shape social learning of both personality and mate preference.

Behavior plays a fundamental role in shaping the origin and fate of species. Mating decisions can act to promote or restrict gene flow, as can personality traits that influence dispersal and niche use. Mate choice and personality are often both learned and therefore influenced by an individual's social environment throughout development. Likewise, the molecular pathways that shape these behaviors may also be co-expressed. In this study on swordtail fish (Xiphophorus birchmanni), we show that female mating preferences for species-typical pheromone cues are entirely dependent on social experience with adult males. Experience with adults also shapes development along the shy-bold personality axis, with shy behaviors arising from exposure to risk-averse heterospecifics as a potential stress-coping strategy. In maturing females, conspecific exposure results in a strong upregulation of olfaction and vision genes compared with heterospecific exposure, as well as immune response genes previously linked to anxiety, learning and memory. Conversely, heterospecific exposure involves an increased expression of genes important for neurogenesis, synaptic plasticity and social decision-making. We identify subsets of genes within the social decision-making network and with known stress-coping roles that may be directly coupled to the olfactory processes females rely on for social communication. Based on these results, we conclude that the social environment affects the neurogenomic trajectory through which socially sensitive behaviors are learned, resulting in adult phenotypes adapted for specific social groupings.

Manipulating the Alpha Level Cannot Cure Significance Testing.

We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = 0.05 to p = 0.005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significance testing altogether. There are alternatives that address study design and sample size much more directly than significance testing does; but none of the statistical tools should be taken as the new magic method giving clear-cut mechanical answers. Inference should not be based on single studies at all, but on cumulative evidence from multiple independent studies. When evaluating the strength of the evidence, we should consider, for example, auxiliary assumptions, the strength of the experimental design, and implications for applications. To boil all this down to a binary decision based on a p-value threshold of 0.05, 0.01, 0.005, or anything else, is not acceptable.

Supervised ordering in IRp: application to morphological processing of hyperspectral images.

A novel approach for vector ordering is introduced in this paper. The generic framework is based on a supervised learning formulation which leads to reduced orderings. A training set for the background and another training set for the foreground are needed as well as a supervised method to construct the ordering mapping. Two particular cases of learning techniques are considered in detail: 1) kriging-based vector ordering and 2) support vector machines-based vector ordering. These supervised orderings may then be used for the extension of mathematical morphology to vector images. In particular, in this paper, we focus on the application of morphological processing to hyperspectral images, illustrating the performance with practical examples.

Reducción indirecta y fijación con placa con invasión mínima de fracturas de tibia en modelo animal: estudio comparativo / Indirect reduction and fixation with plaque with minim invasion of tibial fractures in animal model: comparative study

Se trata de un estudio experimental en modelo animal en el que se realizaron osteosintesis en fracturas cerradas empleando técnica con invasión mínima con placa (MIPO) y se compararon en un grupo control en el que se empleo la técnica convencional de reducción abierta anatómica con placa (RAFI). Se incluyeron veinte conejos machos adultos que se dividieron aleatoramente en dos grupos, en los que se produjeron de la misma manera fracturas diafisiarias de tibia que posteriormente se fijaron con técnica MIPO en diez y RAFI en los diez restantes. En todos los procedimientos se utilizaron placas rectas de 2.7 mm con sus tornillos correspondientes (SYNTHES), siendo los procedimientos realizados por un mismo grupo médico veterinario en todas las ocasiones. A las tres semanas se sacrificaron los conejos y se hizo evaluación histológica de las tibias sometidas a osteosintesis. se realizaron veinte procedimientos y evaluaron en total diecisiete especimenes. Se evaluó el tiempo de consolidación ósea a nivel histológico, encontrandose que en los conejos donde se realizó osteosintesis por técnica de RAFI se tuvo tejido fibrosos en cuatro casos y una mezcla de cartilago y hueso en tres (P<0.001). se tuvieron en cuenta todos los aspectos éticos requeridos por la Sociedad Potectora de Animales para el estudio de técnicas quirúrgicas en animales.