The effects of ethanol on diverse components of choice in the rat: Reward discrimination, preference and relative valuation

Abstract

Alcohol consumption impairs judgment and choice. How alcohol alters these crucial processes is primarily unknown. Choice can be fractionated into different components including reward discrimination, preference and relative valuation that can function together or in isolation depending upon diverse factors including choice context. We examined the diverse components and contextual effects by analyzing the effects of alcohol drinking on choice behavior in a task with a reduced level of temporal and spatial constraints. Rats were trained to drink 10% ethanol during 6 weeks of behavior testing using a combined sucrose-fade and two-bottle free-choice procedure. Two different sucrose pellet outcomes (e.g., constant vs. variable) were presented each week to examine the impact of voluntary drinking on reward-based decision-making. Behavioral contexts of single option, free choice and extinction were examined for each outcome set. Comparisons were made between alcohol and control groups and within the alcohol group over time to inspect choice profiles. Between-group results showed alcohol drinking animals expressed altered place preference, and modified sucrose reward approach latencies. The within-group profile showed that alcohol drinking animals can express adequate reward discrimination, preference, and incentive contrast during free choice. All of these components were significantly reduced during the context of extinction. Control animals were also impacted by extinction but not as severely. The findings point to a need for a greater focus on the context and the diverse components of choice when examining external and internal factors influencing decision-making during alcohol or other substance of abuse exposure.

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Timing of Metastasis in Breast Cancer

In 2015, almost 232,000 women in the United States received a diagnosis of invasive breast cancer, and approximately 40,000 women died of metastatic breast cancer. The leading cause of these deaths was metastatic spread. The timing and distribution of breast-cancer metastases vary considerably. In…

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Instagram Use and Self-Objectification: The Roles of Internalization, Comparison, Appearance Commentary, and Feminism

Abstract

The current study examined potential mediators (i.e., internalization of cultural standards of beauty, engaging in upward and downward appearance comparison, and receiving positive and negative appearance-related commentary), moderators (i.e., feminist beliefs), and moderated mediation of the links between Instagram (an electronic way to share visual images) use and self-objectification and body surveillance among 492 undergraduate women from the Southeast United States. Results revealed that internalization of cultural standards of beauty and engaging in upward appearance comparison uniquely mediated Instagram usage and self-objectification and body surveillance links. Additionally, findings from the moderation analyses indicated that the direct effect of Instagram usage on body surveillance was contingent on feminist beliefs, such that this relationship was only significant among women with lower and moderate feminist beliefs. This finding suggests that higher feminist beliefs play a buffering or protective role whereas lower feminist beliefs play an intensifying role. Implications and future directions are discussed.

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Changing Jobs and Changing Chores? The Longitudinal Association of Women’s and Men’s Occupational Gender-Atypicality and Couples’ Housework Performance

Abstract

Prior research linking occupational sex composition (the proportion of women in an occupation) to housework has yielded conflicting results and relies exclusively on cross-sectional data. The present article extends scholarship on the gendered division of household labor by using longitudinal data from the Panel Study of Income Dynamics (PSID) 1981–2013 to assess how changes in occupational sex composition alter heterosexual married couples' housework performance over time. I find that either spouse's gender-atypical employment (e.g., husband's employment in a predominately female job) is associated with gender-atypical housework performance by both spouses (e.g., higher housework hours for the husband and fewer hours for the wife). The association of women's occupational sex composition with housework is driven by changes in individual women's occupations and both spouses' housework over time. In contrast, the association of men's occupational sex composition with housework is driven by differences between different couples, not by within-couple change over time. Thus, fundamentally different causal mechanisms link women's and men's occupational sex composition to couples' housework performance, and only for women are longitudinal changes in occupational sex composition associated with changes in housework. These findings have important implications for understanding occupation and housework as domains of gender performance.

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The human medial pterygoid muscle: Attachments and distribution of muscle spindles

Abstract

Introduction Published descriptions about the sites of origin of the human medial pterygoid muscle vary and there are few reports on the distribution and density of muscle spindles in this muscle. We aimed to: 1) determine the extent of anatomical variability in the origins and insertions of the superficial and deep heads of the human medial pterygoid muscle, and 2) determine the extent of variation in the distribution of spindles in the two heads of the muscle.

Materials and methods Thirty-nine human cadaver hemi-heads were dissected and the attachments of the medial pterygoid muscle examined. The whole muscle was removed, weighed, cut into segments and embedded in wax for light microscopy. Sections were stained with Weigert-Van Gieson stain and scanned into digital images. Spindles were manually counted.

Results In seven specimens, the deep head of the muscle arose from the medial surface of the lateral pterygoid plate and the pterygoid fossa. In 28 specimens, the origin extended onto the lateral surface of the medial pterygoid plate.

There were abundant muscle spindles in the middle of the muscle, slightly fewer 1cm toward the insertion, significantly fewer 1cm toward the origin, and few or no spindles near the origins of the superficial and deep heads or near their insertion.

Conclusion Firstly, this study shows that in 72% of the specimens examined, the origin of the medial pterygoid is wider than conventionally described in anatomical textbooks. Secondly, the segmental distribution of muscle spindles is described for the first time. This article is protected by copyright. All rights reserved.

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Hepatoprotective Effect of Citral on Acetaminophen-Induced Liver Toxicity in Mice

High doses of acetaminophen (APAP) lead to acute liver damage. In this study, we evaluated the effects of citral in a murine model of hepatotoxicity induced by APAP. The liver function markers alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transferase (γGT) were determined to evaluate the hepatoprotective effects of citral. The livers were used to determine myeloperoxidase (MPO) activity and nitric oxide (NO) production and in histological analysis. The effect of citral on leukocyte migration and antioxidant activity was evaluated in vitro. Citral pretreatment decreased significantly the levels of ALT, AST, ALP, and γGT, MPO activity, and NO production. The histopathological analysis showed an improvement of hepatic lesions in mice after citral pretreatment. Citral inhibited neutrophil migration and exhibited antioxidant activity. Our results suggest that citral protects the liver against liver toxicity induced by APAP.

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Response of Local Nitric Oxide Release to Manual Acupuncture and Electrical Heat in Humans: Effects of Reinforcement Methods

This study was to examine the influences of manual acupuncture (MA) and electrical heat corresponding to reinforcing methods on nitric oxide (NO) release over the skin regions in humans. A device with collecting solution was taped to the skin surface along pericardium (PC) or lung (LU) meridian. Acupuncture needles were gently inserted into PC 4 with reinforcing stimulation (low force/rate) for 20 minutes in the MA group. LU11 on the finger was heated (43-44°C) by electrical heat for 20 minutes. Biocapture was consecutively conducted for two 20-minute intervals during and after each treatment. Total nitrite and nitrate () in the collecting samples were quantified using chemiluminescence in blinded fashion. Baseline levels are higher and tended to be higher over PC and LU acupoints during the 1st biocapture. levels over PC regions were consistently increased by MA during both intervals. concentrations over LU acupoints were increased and tended to be increased by electrical heat in the 1st and 2nd biocapture. The results suggest that reinforcing MA and electrical heat induce NO released from the local skin regions with higher levels at acupoints, which improve local circulation and contribute to the beneficial effects of the therapies.

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