Patterns of Brain Activation when Mothers View Their Own Child and Dog: An fMRI Study

Neural substrates underlying the human-pet relationship are largely unknown. We examined fMRI brain activation patterns as mothers viewed images of their own child and dog and an unfamiliar child and dog. There was a common network of brain regions involved in emotion, reward, affiliation, visual processing and social cognition when mothers viewed images of both their child and dog. Viewing images of their child resulted in brain activity in the midbrain (ventral tegmental area/substantia nigra involved in reward/affiliation), while a more posterior cortical brain activation pattern involving fusiform gyrus (visual processing of faces and social cognition) characterized a mother''s response to her dog. Mothers also rated images of their child and dog as eliciting similar levels of excitement (arousal) and pleasantness (valence), although the difference in the own vs. unfamiliar child comparison was larger than the own vs. unfamiliar dog comparison for arousal. Valence ratings of their dog were also positively correlated with ratings of the attachment to their dog. Although there are similarities in the perceived emotional experience and brain function associated with the mother-child and mother-dog bond, there are also key differences that may reflect variance in the evolutionary course and function of these relationships.     

Transcriptomic Identification of ADH1B as a Novel Candidate Gene for Obesity and Insulin Resistance in Human Adipose Tissue in Mexican Americans from the Veterans Administration Genetic Epidemiology Study (VAGES)

Type 2 diabetes (T2D) is a complex metabolic disease that is more prevalent in ethnic groups such as Mexican Americans, and is strongly associated with the risk factors obesity and insulin resistance. The goal of this study was to perform whole genome gene expression profiling in adipose tissue to detect common patterns of gene regulation associated with obesity and insulin resistance. We used phenotypic and genotypic data from 308 Mexican American participants from the Veterans Administration Genetic Epidemiology Study (VAGES). Basal fasting RNA was extracted from adipose tissue biopsies from a subset of 75 unrelated individuals, and gene expression data generated on the Illumina BeadArray platform. The number of gene probes with significant expression above baseline was approximately 31,000. We performed multiple regression analysis of all probes with 15 metabolic traits. Adipose tissue had 3,012 genes significantly associated with the traits of interest (false discovery rate, FDR ≤ 0.05). The significance of gene expression changes was used to select 52 genes with significant (FDR ≤ 10^-4) gene expression changes across multiple traits. Gene sets/Pathways analysis identified one gene, alcohol dehydrogenase 1B (ADH1B) that was significantly enriched (P < 10^-60) as a prime candidate for involvement in multiple relevant metabolic pathways. Illumina BeadChip derived ADH1B expression data was consistent with quantitative real time PCR data. We observed significant inverse correlations with waist circumference (2.8 x 10^-9), BMI (5.4 x 10^-6), and fasting plasma insulin (P < 0.001). These findings are consistent with a central role for ADH1B in obesity and insulin resistance and provide evidence for a novel genetic regulatory mechanism for human metabolic diseases related to these traits.     

Fish scale shape follows predictable patterns of variation based on water column position,body size,and phylogeny

Evolutionary Ecology - The influence of environment and phylogeny on morphological characteristics of organisms is well documented. However, little is known about how these factors influence scale...     

Hox patterning of the vertebrate rib cage

Unlike the rest of the axial skeleton, which develops solely from somitic mesoderm, patterning of the rib cage is complicated by its derivation from two distinct tissues. The thoracic skeleton is derived from both somitic mesoderm, which forms the vertebral bodies and ribs, and from lateral plate mesoderm, which forms the sternum. By generating mouse mutants in Hox5, Hox6 and Hox9 paralogous group genes, along with a dissection of the Hox10 and Hox11 group mutants, several important conclusions regarding the nature of the ;Hox code' in rib cage and axial skeleton development are revealed. First, axial patterning is consistently coded by the unique and redundant functions of Hox paralogous groups throughout the axial skeleton. Loss of paralogous function leads to anterior homeotic transformations of colinear regions throughout the somite-derived axial skeleton. In the thoracic region, Hox genes pattern the lateral plate-derived sternum in a non-colinear manner, independent from the patterning of the somite-derived vertebrae and vertebral ribs. Finally, between adjacent sets of paralogous mutants, the regions of vertebral phenotypes overlap considerably; however, each paralogous group imparts unique morphologies within these regions. In all cases examined, the next-most posterior Hox paralogous group does not prevent the function of the more-anterior Hox group in axial patterning. Thus, the ;Hox code' in somitic mesoderm is the result of the distinct, graded effects of two or more Hox paralogous groups functioning in any anteroposterior location.     

Stage of the Estrous Cycle Does Not Influence Myocardial Ischemia–Reperfusion Injury in Rats (Rattus norvegicus)

Even though cardiovascular disease is the leading cause of death for men and women, the vast majority of animal studies use male animals. Because female reproductive hormones have been associated with cardioprotective states, many investigators avoid using female animals because these hormones are cyclical and may introduce experimental variability. In addition, no studies have investigated the specific effects of the estrous cycle on cardiac ischemic injury. This study was conducted to determine whether the estrous cycle stage influences the susceptibility to ischemic injury in rat hearts. Estrous cycle stage was determined by using vaginal smear cytology, after which hearts underwent either in vivo (surgical) or ex vivo (isolated) ischemia–reperfusion injury. For in vivo studies, the left anterior coronary artery was ligated for 25 min of ischemia and subsequently released for 120 min of reperfusion. Infarct sizes were 42% ± 6%; 49% ± 4%; 40% ± 9%; 47% ± 9% of the zone-at-risk for rats in proestrus, estrus, metestrus, and diestrus, respectively. For ex vivo studies, isolated, perfused hearts underwent global ischemia and reperfusion for 25 and 120 min, respectively. Similar to our in vivo studies, the ex vivo rat model showed no significant differences in susceptibility to infarction or extent of cardiac arrhythmia according to estrous stage. To our knowledge, these studies provide the first direct evidence that the stage of estrous cycle does not significantly alter cardiac ischemia–reperfusion injury in rats.Abbreviations: VF, ventricular fibrillation; VT, ventricular tachycardiaCardiovascular disease remains the leading cause of morbidity and mortality throughout the industrialized world, with ischemic heart disease being a major manifestation of cardiovascular disease. Many investigators use animal models to advance our understanding of the etiology and mechanisms involved. Although ischemic heart disease is the leading cause of death for both men and women, the overwhelming majority of studies use male animals. Perhaps the most common reason for this practice is that physiologic fluctuations in female reproductive hormones such as estrogen may be a confounding variable, given the influence of female reproductive hormones on various organ systems.²⁵ Despite the assertion that cyclical variations in female reproductive hormones may confound experimental studies, few data are available that support estrous-cycle–dependent variations in susceptibility to ischemic heart injury.Epidemiologic studies suggest that, compared with men, women have lower cardiac mortality prior to undergoing menopause.⁴⁰ Consistent with human studies, experimental models in several species commonly show that the degree of cardiac injury in young female animals is lower than that in male counterparts.^7,9,21,22,42 Exogenous administration of estrogen has a clear effect in reducing injury,^14,15 but whether endogenous cyclical variations in female reproductive hormones affect cardiac injury is not known.Rats and mice are commonly used species to examine cardiac ischemia–reperfusion injury. Unlike humans, rodents do not undergo menstruation, during which the uterine endometrium sloughs off and is expelled through the vagina, but rather the uterine lining of rodents is reabsorbed during an estrous cycle.²⁴ The rat estrous cycle is typically 4 to 5 d in length and is defined by 4 separate stages: proestrus, estrus, metestrus, and diestrus. Proestrus is characterized by increasing levels of estrogen. At the end of proestrus, ovulation (signaled by luteinizing hormone) occurs and marks the beginning of the estrus cycle. During metestrus and diestrus, the uterine lining regenerates, and the cycle starts again.^24,33 These stages induce changes in the composition of the epithelium of the vagina and the presence of inflammatory cells, which can easily be detected by using vaginal cytology.^18,35We conducted the current study to determine whether estrous cycle stage influences the susceptibility to ischemia–reperfusion injury in the rat heart. Because the stage of the estrous cycle may influence cardiac injury either directly (via a direct effect of circulating hormones), or indirectly (by inducing changes that are intrinsic to the heart), we used both in vivo and ex vivo models of injury.