Asymmetry of brain aromatase activity: region- and sex-specific developmental patterns.

Developmental patterns of aromatase activity (AA) were characterized in individual forebrain regions of the rat at gestational day (GD) 22 and postnatal days (PN) 6 and 15. Aromatase activity was measured separately in homogenates of left and right preoptic area, anterior amygdaloid area, medial amygdaloid nucleus, anterior hypothalamic area and posterior hypothalamic area, by the tritiated water method with [1 beta-3H]-androstenedione as a substrate. Region- and sex-dependent asymmetries of AA with either left-to-right or right-to-left gradients were found. They change between GD22 and PN6 and PN15 according to region-specific patterns. Thus, AA of the male medial amygdaloid nucleus of the left side is higher at GD22, lower at PN6 and equal to the right side at PN15; in females, AA of the left side is lower than AA of the right side at GD22 and higher at PN6 and PN15. In preoptic area, a side difference (left side higher) was only detected in males. Asymmetries may result from differences in the expression of the enzyme by individual cell groups, or from differences in the number of cells per area expressing the enzyme. In either case, the stage-dependent patterns of asymmetry in AA would be expected to influence sex steroid-dependent differentiation processes in individual forebrain areas.     

Courtship in Drosophila mosaics: sex-specific foci for sequential action patterns.

Mosaic fate mapping is used to locate the foci determining sex-specific steps in the mating behavior of Drosophila. Male performance of following females and displaying wing vibration toward them requires that a focus inside the head be constituted of male tissue, regardless of the sex of the head sense organs, the legs, the wings, or the thoracic ganglion. For attempted copulation to occur, a second focus in the thoracic region must also be male. Courtship by males is induced by a posteriorly located focus in the female, but an anterior female focus determines receptivity to attempted copulation. The interplay of male and female foci in the complex behavioral sequence is delineated.     

Origin of variability in quantal size in cultured hippocampal neurons and hippocampal slices.

The size of synaptic quanta has been found to display considerable variation in cultured hippocampal neurons, but the source of this variability was previously unknown. We have now compared the properties of locally evoked miniature excitatory postsynaptic currents in cultured hippocampal neurons and in thin hippocampal slices using whole-cell patch-clamp recordings. The variability in miniature excitatory postsynaptic current size was similar in both preparations and occurred in cultured neurons when only one or a few synaptic boutons were stimulated. Thus, the variability in miniature excitatory postsynaptic current amplitude is not an artifact of cultured neurons and arises predominantly from variability within a single bouton. Possible origins of this variability are discussed.     

Serum cortisol levels predict infarct size and patient mortality.

We have investigated prospectively the serum cortisol response to acute myocardial infarction in 70 consecutive patients admitted to a coronary care unit and we have shown that the levels are significantly raised early in the course of the illness and prior to elevation of the cardiac specific enzyme fraction, creatine kinase MB. The magnitude of the cortisol response is related to the size of the ensuing infarction (rs = 0.54) as calculated from the total creatine kinase MB release (P < 0.001) and very high levels (> 2000 mumol/l) are predictive of mortality (P < 0.05). Serum cortisol levels may have a role in the early identification of myocardial infarction and in predicting those patients with a poor prognosis.     

Tuberculosis transmission patterns in a high-incidence area: a spatial analysis.

SETTING: In the Cape Town suburbs of Ravensmead and Uitsig, tuberculosis has reached epidemic levels, with notifications of 1340/100,000 in 1996. These suburbs are characterised by overcrowding, high unemployment and poverty. It is traditionally believed that tuberculosis transmission takes place mainly in households after close contact with an infectious person. Studies have recently linked tuberculosis transmission to locations outside the household, and have associated these places with a particular high-risk lifestyle. Anthropological studies in some suburbs of Cape Town, in which a very high number of local drinking places (shebeens) were identified (17 per km2), have suggested that social drinking is part of such a lifestyle. OBJECTIVE: To investigate various risk factors and places of transmission of tuberculosis using a geographical information system (GIS). RESULTS AND CONCLUSION: The 1128 bacteriologically-proven cases of tuberculosis studied over the period 1993-1998 were investigated using spatial epidemiological techniques of exploratory disease mapping. Point pattern analysis and spatial statistics indicated clustering of cases in the areas of high incidence. Significant associations of tuberculosis notifications were found with unemployment, overcrowding and number of shebeens per enumerator sub-district. High tuberculosis notifications with unemployment and its associated poverty emerged as the strongest association.     

Evolution of behavior by density-dependent natural selection.

Theories of density-dependent natural selection predict that evolution should favor those genotypes with the highest per capita rates of population growth under the current density conditions. These theories are silent about the mechanisms that may give rise to these increases in density-dependent growth rates. We have observed the evolution of six populations of Drosophila melanogaster recently placed in crowded environments after nearly 200 generations at low-population density in the laboratory. After 25 generations in these crowded cultures all six populations showed the predicted increase in population growth rates at high-population density with the concomitant decrease in their growth rates at low densities. These changes in rates of population growth are accompanied by changes in the feeding and pupation behavior of the larvae: those populations that have evolved at high-population densities have higher feeding rates and are less likely to pupate on or near the food surface than populations maintained at low densities. These changes in behavior serve to increase the competitive ability of larvae for limited food and reduce mortality under crowded conditions during the pupal stage of development. A detailed understanding of the mechanisms by which populations evolve under density-dependent natural selection will provide a framework for understanding the nature of trade-offs in life history evolution.     

Gene-expression patterns predict phenotypes of immune-mediated thrombosis

Antiphospholipid antibody syndrome (APS) is a complex autoimmune thrombotic disorder with defined clinical phenotypes. Although not all patients with elevated antiphospholipid antibody (aPLA) levels develop complications, the severity of these potential events mandates aggressive and extended lifelong anti-thrombotic therapy. One hundred twenty-nine patients (57 patients with APS and venous thromboembolism [VTE], 32 patients with VTE without aPLA, 32 patients with aPLA only, and 8 healthy patients) were enrolled. RNA from peripheral-blood collection was used for DNA microarray analysis. Patterns of gene expression that characterize APS as well as thrombosis in the presence of aPLA were identified by hierarchical clustering and binary regression methods. Gene-expression profiles identify and predict individuals with APS from patients with VTE without aPLA. Importantly, similar methods identified expression profiles that accurately predicted those patients with aPLA at high risk for thrombotic events. All profiles were validated in independent cohorts of patients. The ability to predict APS, but more importantly, those patients at risk for venous thrombosis, represents a paradigm for a genomic approach that can be applied to other populations of patients with venous thrombosis, providing for more effective clinical management of disease, while also reflecting the possible underlying biologic processes.     

Evolution of altruistic behavior by kin selection: an alternative approach.

The evolution of altruistic and selfish behavior by kin selection has been analyzed previously by asking which types of behavior are favored by natural selection. A type of behavior is defined as a given cost/benefit ratio, c/b, in terms of Darwinian fitness. An alternative approach is to consider c/b itself as a quantitative character subject to natural selection and evolving toward an equilibrium. This approach allows consideration of a continuum of behavioral options as opposed to just two alternatives as in the previous work. Environmental restrictions on the availability of opportunities for fitness transactions are imposed so that the total benefit an individual can provide for or take from his relatives increases with his c/b ratio. General conditions for stable equilibria are derived. These depend only on the coefficient of relationship between donor and recipient (r) and the function describing the availability of benefit. They are independent of the heritability and variance in the population. Under weak selection, the equilibrium c/b ratio will be r/2 for altruistic behavior and 1/(2r) for selfish behavior. By contrast, standard theory predicts that all altruistic acts with c/b ratios less than r will be favored, and no equilibrium can be predicted except under certain special conditions where only two behavioral options are available. In general, these results show that evolution of the donor's behavior (altruism) tends to maximize the quantity rb--c, and evolution of the recipient (selfish behavior) maximizes b--rc.     

Family history of cardiovascular disease does not predict risk-reducing behavior.

BACKGROUND: Family history is one of the main risk factors for cardiovascular disease, especially in the younger population. These individuals, being closely related to young symptomatic patients, are anticipated to have a high rate of risk factors but also to control them aggressively. The aim of the study was to evaluate the association between family history of cardiovascular disease and risk factors that control as well as reduce risk-reducing behavior among young, healthy adults. DESIGN AND METHODS: Demographic, clinical and lifestyle parameters of career service personnel of the Israeli Defense Forces, who were checked at the staff periodic examination center, were evaluated. Behavioral and clinical parameters of participants, with and without cardiovascular family history, were compared. RESULTS: The study cohort comprised 41,099 patients (36,236 men and 4863 women). Of those, 3802 men and 628 women with a family history of cardiovascular disease were identified. Male individuals had a higher rate of treatable risk factors like, obesity (P<0.0005), high blood pressure (P<0.0005), high plasma glucose (P<0.0005) and dyslipidemia (P<0.0005) than individuals without a family history. Among the women, the rate of these risk factors was higher than in the control groups but was statistically significant only for obesity, high blood pressure and high glucose levels. Risk-reducing behavior like regular physical activity and nonsmoking status in both the sexes did not differ between the groups. CONCLUSION: Members of the young population with a family history of cardiovascular disease is easily identified but remains largely uncontrolled. Special attention and continued education are required to modify their behavioral and medical parameters.     

Evolution of neuroendocrine mechanisms that regulate sexual behavior.

Whiptail lizards provide a unique system to study evolution of brain mechanisms because both ancestral (sexual) and descendant (parthenogenetic) species exist. Parthenogenetic whiptails enable us to avoid the two major confounds in sex differences research - males and females that differ both genetically and hormonally. Parthenogens are females that reproduce clonally, yet display alternately female-like and male-like pseudosexual behavior. Thus, the neural circuitry underlying male and female sexual behavior can be examined within the 'same' brain (same genome), enabling us to see how neuroendocrine mechanisms controlling mounting behavior change. In ancestral males, testicular androgens control sexual behavior, whereas male-like pseudocopulatory behavior is controlled by ovarian progesterone in parthenogens, revealing that progesterone is important in regulating sexual behavior in male vertebrates, including mammals.     

Understanding hippocampal activity by using purposeful behavior: place navigation induces place cell discharge in both task-relevant and task-irrelevant spatial reference frames

Continuous rotation of an arena in a cue-rich room dissociates the stationary room-bound information from the rotating arena-bound information. This disrupted spatial discharge in the majority of place cells from rats trained to collect randomly scattered food. In contrast, most place cell firing patterns recorded from rats trained to solve a navigation task on the rotating arena were preserved during the rotation. Spatial discharge was preserved in both the task-relevant stationary and the task-irrelevant rotating reference frames, but firing was more organized in the task-relevant frame. It is concluded that, (i) the effects of environmental manipulations can be understood with confidence only when the rat's purposeful behavior is used to formulate interpretations of the data, and (ii) hippocampal place cell activity is organized in multiple overlapping spatial reference frames.     

Evolution of patterns on Conus shells

The pigmentation patterns of shells in the genus Conus can be generated by a neural-network model of the mantle. We fit model parameters to the shell pigmentation patterns of 19 living Conus species for which a well resolved phylogeny is available. We infer the evolutionary history of these parameters and use these results to infer the pigmentation patterns of ancestral species. The methods we use allow us to characterize the evolutionary history of a neural network, an organ that cannot be preserved in the fossil record. These results are also notable because the inferred patterns of ancestral species sometimes lie outside the range of patterns of their living descendants, and illustrate how development imposes constraints on the evolution of complex phenotypes.     

Evolution meets biopsychosociality: an analysis of addictive behavior

Evolutionary theory can inform the biopsychosocial approach to addictive behavior through the use of adaptationist thinking, or how natural selection has shaped the mechanisms and processes underlying addiction. Covering how evolutionary theory relates to biology, psychology and sociality, this paper examines three components to drug use and abuse: a biological mechanism (mesolimbic dopamine), a developmental trajectory (attachment) and a social phylogeny (dominance, submission, social dependence). The paper argues for a salience (or wanting) view of the function of dopamine; outlines how attachment affects time perspective, closure of internal models and self-regulation; and examines how inequality affects drug abuse and how social dependence and manipulative behaviors can play a role in relationships with drugs. The article concludes with an analysis of how the adaptive approach applies to interventions against addictive behavior.     

空间插值法在人群包虫病患病率预测中的应用

目的探索不同空间插值方法在人群包虫病患病率预测中的应用并比较其效果。方法以四川、西藏、甘肃和青海四省(区)青藏高原地区2012年全国包虫病流行情况调查获得的124个藏区县的人群包虫病患病率数据为基础,使用Arcgis10.0软件,采用局部多项式插值法、反距离权重插值法和kriging插值法进行空间插值,比较青海省治多县和玛多县人群包虫病患病率推算的效果。结果 3种方法预测的精度各有优势,对青海省治多县和玛多县人群包虫病患病率误差最小的为Kriging插值方法,预测的患病率分别为2.04%和5.28%。结论空间插值方法可用于青海省治多县和玛多县人群包虫病患病率预测,以Kriging插值法的预测效果较好。     

Short-term plasticity constrains spatial organization of a hippocampal presynaptic terminal

Although the CA3-CA1 synapse is critically important for learning and memory, experimental limitations have to date prevented direct determination of the structural features that determine the response plasticity. Specifically, the local calcium influx responsible for vesicular release and short-term synaptic facilitation strongly depends on the distance between the voltage-dependent calcium channels (VDCCs) and the presynaptic active zone. Estimates for this distance range over two orders of magnitude. Here, we use a biophysically detailed computational model of the presynaptic bouton and demonstrate that available experimental data provide sufficient constraints to uniquely reconstruct the presynaptic architecture. We predict that for a typical CA3-CA1 synapse, there are ～70 VDCCs located 300 nm from the active zone. This result is surprising, because structural studies on other synapses in the hippocampus report much tighter spatial coupling. We demonstrate that the unusual structure of this synapse reflects its functional role in short-term plasticity (STP).     

The effect of childhood trauma on spatial cognition in adults: a possible role of sex

Although animal evidence indicates that early life trauma results in pervasive hippocampal deficits underlying spatial and cognitive impairment, visuo-spatial data from adult humans with early childhood adversity are lacking. We administered 4 tests of visuo-spatial ability from the Cambridge Neuorpsychological Test Automated Battery (CANTAB) to adults with a history of childhood trauma (measured by the Childhood Trauma Questionnaire) and a matched sample of healthy controls (trauma/control?=?27/28). We observed a significant effect of trauma history on spatial/pattern learning. These effects could not be accounted for by adverse adult experiences, and were sex-specific, with prior adversity improving performance in men but worsening performance in women, relative to controls. Limitations include the small sample size and reliance of our study design on a retrospective, self report measure. Our results suggest that early adversity can lead to specific and pervasive deficits in adult cognitive function.     

Criminal behavior patterns of female addicts: a comparison of findings in two cities.

A great deal of the literature on addiction is devoted to analyses of the relation between drugs of addiction and crime among males. The few studies which have undertaken to describe the relationship between crime and addiction in females have generally concluded that addicted females either become prostitutes or they commit crimes against property. This study of addicted female arrestees in Denver (N = 153) and Philadelphia (N = 227) concluded that the hypothesized either-or pattern of addicted female criminal behavior is overly simplistic. Rather, four criminal behavior patterns of female arrestees are found: (1) prostitutes without a history of serious crimes, (2) females with a history of serious crimes who are not prostitutes, (3) females who are both prostitutes and commit serious crimes, and (4) females who are not prostitutes and who commit only minor offenses. The utility of the four-pattern typology is borne out by analyses which indicate that these patterns are typical of different groups of female addicts and are not stages in a unitary socialization pattern involving drugs, prostitution, and crime.