Maternal effects on anogenital distance in a wild marmot population

Peer reviewedPublisher PD

Neurodevelopmental model explaining associations between sex hormones, personality, and eating pathology

Clinical scientists have been investigating the relationships between sex hormones, personality, and eating disorders for decades. However, there is a lack of direct research that addresses whether personality mediates or moderates the relationships between sex hormones and eating pathology. Moreover, the neural mechanisms that underlie the interactive associations between these variables remain unclear. This review aims to summarize the associations between these constructs, describe a neural mechanism mediating these relationships, and offer clinical strategies for the early identification and intervention of eating disorders. The gathered evidence shows that aggressiveness, impulsivity, and obsessive-compulsiveness may mediate or moderate the relationships between sex hormones and eating pathology, but only among females. Furthermore, sex hormone receptor density in the mesocorticolimbic dopamine pathway may explain the neural mechanism of these associations. Future research should use more comprehensive personality measurements and assess the mediation and moderation effects of temperament while taking the hormone levels of women across menstrual cycles into account. Additionally, electroencephalography and functional magnetic resonance imaging should be implemented to directly assess brain activity and corroborate these findings.Accepted manuscrip

A Genetic Animal Model of Alcoholism for Screening Medications to Treat Addiction

The purpose of this review is to present up-to-date pharmacological, genetic, and behavioral findings from the alcohol-preferring P rat and summarize similar past work. Behaviorally, the focus will be on how the P rat meets criteria put forth for a valid animal model of alcoholism with a highlight on its use as an animal model of polysubstance abuse, including alcohol, nicotine, and psychostimulants. Pharmacologically and genetically, the focus will be on the neurotransmitter and neuropeptide systems that have received the most attention: cholinergic, dopaminergic, GABAergic, glutamatergic, serotonergic, noradrenergic, corticotrophin releasing hormone, opioid, and neuropeptide Y. Herein, we sought to place the P rat's behavioral and neurochemical phenotypes, and to some extent its genotype, in the context of the clinical literature. After reviewing the findings thus far, this chapter discusses future directions for expanding the use of this genetic animal model of alcoholism to identify molecular targets for treating drug addiction in general

Hand pattern indicates prostate cancer risk

BACKGROUND: The ratio of digit lengths is fixed in utero, and may be a proxy indicator for prenatal testosterone levels. METHODS: We analysed the right-hand pattern and prostate cancer risk in 1524 prostate cancer cases and 3044 population-based controls. RESULTS: Compared with index finger shorter than ring finger (low 2D : 4D), men with index finger longer than ring finger (high 2D : 4D) showed a negative association, suggesting a protective effect with a 33% risk reduction (odds ratio (OR) 0.67, 95% confidence interval (CI) 0.57-0.80). Risk reduction was even greater (87%) in age group <60 (OR 0.13, 95% CI 0.09-0.21). CONCLUSION: Pattern of finger lengths may be a simple marker of prostate cancer risk, with length of 2D greater than 4D suggestive of lower risk. British Journal of Cancer (2011) 104, 175-177. doi:10.1038/sj.bjc.6605986 www.bjcancer.com Published online 30 November 2010 (C) 2011 Cancer Research U

Selective Breeding for a Behavioral Trait Changes Digit Ratio

The ratio of the length of the second digit (index finger) divided by the fourth digit (ring finger) tends to be lower in men than in women. This 2D∶4D digit ratio is often used as a proxy for prenatal androgen exposure in studies of human health and behavior. For example, 2D∶4D ratio is lower (i.e. more “masculinized”) in both men and women of greater physical fitness and/or sporting ability. Lab mice have also shown variation in 2D∶4D as a function of uterine environment, and mouse digit ratios seem also to correlate with behavioral traits, including daily activity levels. Selective breeding for increased rates of voluntary exercise (wheel running) in four lines of mice has caused correlated increases in aerobic exercise capacity, circulating corticosterone level, and predatory aggression. Here, we show that this selection regime has also increased 2D∶4D. This apparent “feminization” in mice is opposite to the relationship seen between 2D∶4D and physical fitness in human beings. The present results are difficult to reconcile with the notion that 2D∶4D is an effective proxy for prenatal androgen exposure; instead, it may more accurately reflect effects of glucocorticoids, or other factors that regulate any of many genes

Aggression Unleashed: Neural Circuits from Scent to Brain

Aggression is a fundamental behavior with essential roles in dominance assertion, resource acquisition, and self-defense across the animal kingdom. However, dysregulation of the aggression circuitry can have severe consequences in humans, leading to economic, emotional, and societal burdens. Previous inconsistencies in aggression research have been due to limitations in techniques for studying these neurons at a high spatial resolution, resulting in an incomplete understanding of the neural mechanisms underlying aggression. Recent advancements in optogenetics, pharmacogenetics, single-cell RNA sequencing, and in vivo electrophysiology have provided new insights into this complex circuitry. This review aims to explore the aggression-provoking stimuli and their detection in rodents, particularly through the olfactory systems. Additionally, we will examine the core regions associated with aggression, their interactions, and their connection with the prefrontal cortex. We will also discuss the significance of top-down cognitive control systems in regulating atypical expressions of aggressive behavior. While the focus will primarily be on rodent circuitry, we will briefly touch upon the modulation of aggression in humans through the prefrontal cortex and discuss emerging therapeutic interventions that may benefit individuals with aggression disorders. This comprehensive understanding of the neural substrates of aggression will pave the way for the development of novel therapeutic strategies and clinical interventions. This approach contrasts with the broader perspective on neural mechanisms of aggression across species, aiming for a more focused analysis of specific pathways and their implications for therapeutic interventions

Characterizing Microglia Morphology in the Frontal Cortex of Pair-Bonded and Unpaired Prairie Voles (Microtus ochrogaster)

Microtus ochrogaster, monogamous prairie voles, serve as translational animal models for studying monogamy and pair bonding. Microglia, the resident immune cells of the brain, are one of several cell types still poorly understood in non-classical animal models including prairie voles. Microglia are known to play mechanistic roles in mediating social behaviors using inflammatory signaling, but the relationship between microglia reactivity and pair bonding has not yet been investigated. The present study first developed a robust protocol for quantitative histological visualization of microglia in Microtus ochrogaster. Second, it investigated differences in microglia morphology, a reliable index of microglia reactivity and function, in pair-bonded vs. unpaired voles. Sections containing prefrontal cortex (PFC) and anterior cingulate cortex (ACC) were stained for ionized calcium-binding adaptor molecule I (Iba1) using immunohistochemistry (IHC). IHC results provided evidence for the successful use of murine histological protocols in prairie voles. Quantification results revealed a sexually dimorphic effect of pair bonding on microglia: somas were significantly larger in pair-bonded vs. unpaired females, and somas were significantly smaller in pair-bonded vs. unpaired males. Additionally, somas were significantly larger in unpaired males than females, with larger somas indicating higher microglia reactivity. While conclusions are limited due to the small sample size, results provide novel characterization of microglia morphology in the frontal cortex and elucidate how pair bonding may influence microglia function in a sexually dimorphic manner