1,720,987 research outputs found
An introduction to the Special Issue on “Sports Science: Evolutionary Perspectives and Biological Mechanisms”
No full textThe goal of the special issue on “Sports science: evolutionary perspectives and biological mechanisms” was to build a bridge to help the development of a coherent and unifying approach to the study of sport science within an evolutionary framework. By focusing specifically on the biological and psychological dynamics of sport performance and competition, we asked if sports can be used to study the evolution of human behavior, biology and psychology. Likewise, we asked whether this evolutionary approach could improve our understandings of the physical and psychological limits of human athletic performance and health
The Influence of Endogenous Opioids on the Relationship between Testosterone and Romantic Bonding
No full textThe endogenous opioid system has received attention and extensive research for its effects on reward, pleasure, and pain. However, relative to other neurochemicals, such as oxytocin, vasopressin and dopamine, the function of opioids in regulating human attachment, sociosexuality, and other aspects of human sociality has not received much consideration. For example, nonapeptides (oxytocin and vasopressin) have been extensively studied in animals and humans for their possible roles in mother-offspring attachment, romantic attachment, fatherhood, and social cognition. Likewise, others have proposed models wherein oxytocin and vasopressin are moderators of the relationship between steroid hormones and human social behaviors. Recently, opioids have generated renewed interest in relation to social pain, and importantly, the brain opioid hypothesis of social attachment (BOTSA), which suggests that endogenous opioids are a key implementer in primate and human bonding, has received some support. Here we focus on romantic bonds by proposing that endogenous opioids are an important mechanism mediating reproductive trade-offs through their inhibitory effects on testosterone production
Prenatal exposure of mice to an environmental estrogen alters sex differences in brain and behavior
No full text56. PRENATAL EXPOSURE OF MICE TO A LOW-DOSE
ENVIRONMENTAL ESTROGEN ALTERS SEX DIFFERENCES IN
BRAIN AND BEHAVIOR. Palanza; P:; Ponzi, D., Gioiosa, L., Flugge, G.,
Parmigiani, S., and Fuchs, E. Dipartimento di Biologia Evolutiva,
Universita` di Parma. Laboratory of Neurobiology, German Primate
Center, Goettingen.
The presence in the environment to a large number of environmental
and industrial compounds that have estrogenic activity (Environmental
Estrogens, EE) raises major health concerns. Sexually dimorphic behaviors
are particularly useful to study the effects of low concentrations of EE,
similar to environmental contamination, because they are highly sensitive to
alterations of the endocrine mileu. Behavior is the endpoint of complex,
integrated systems and therefore is a good biomarker of neuroendocrine and
neurobiological alterations. We investigated the effects of prenatal exposure
(via maternal treatment) to an environmental-like, low dose of bisphenol A
(BPA, an estrogenic compound used in food industry) on mice behavioral
response to novelty and on the noradrenergic system in the brain. Mice
were tested in a free-choice novelty preference test at adolescence, in a freeexploratory
open field and elevated plus-maze (EPM) as adults. Both
adolescent and adult mice exposed to BPAshowed either a decrease or a
reversion in sexual differences in response to novelty. Contrary to the
control profile, BPA-exposed males and females did not differ in exploration,
an effect due mainly to changes in BPA-exposed females relative to
controls. As adults, mice were sacrificed and their brain were analyzed for
alpha2 adrenergic receptor system in locus coeruleus (LC) and preoptic area
(PO). Control mice showed a sexually dimorphic profile of receptor density
in the PO, while prenatal BPA-exposure lowered such sex differences;
BPA-exposed males showed increased receptors number, thus resulting
more similar to the control females’ profile. In both the PO and LC of
exposed animals, a decreased affinity of alpha2-adrenergic receptors was
observed
Day-to-day variation of salivary cortisol and dehydroepiandrosterone (DHEA) in children from a rural Dominican community
Full text linkThis study examines day-to-day patterns of salivary cortisol and dehydroepiandrosterone (DHEA) under baseline conditions and in response to mild stress among 59 children residing in a rural Caribbean village. Cortisol secretion showed the typical circadian variation with high levels in the morning. Children showed significant increases of cortisol before and during a videotaped interview when compared to routine days. DHEA levels were positively associated with cortisol levels; however, within-day secretion of salivary DHEA was more stable than cortisol and DHEA levels did not change significantly during the day. Average DHEA concentrations were positively associated with age but did not show the sharp increase that is usually observed at the onset of adrenarche. These results highlight both similarities and differences in the secretion of cortisol and DHEA during childhood among rural and industrialized human populations
Proximate and ultimate causes of ritual behavior
No full textRitual behaviour, intended as a specific, repetitive and rigid form of action flow, appears both in social and non-social environmental contexts, representing an ubiquitous phenomenon in animal life including human individuals and cultures. The purpose of this contribution is to investigate an evolutionary continuum in proximate and ultimate causes of ritual behavior. A phylogenetic homology in proximal mechanisms can be found, based on the repetition of genetically programmed and/or epigenetically acquired action patterns of behavior. As far as its adaptive significance, ethological comparative studies show that the tendency to ritualization is driven by the unpredictability of social or ecological environmental stimuli. In this perspective, rituals may have a “homeostatic” function over unpredictable environments, as further highlighted by psychopathological compulsions. In humans, a circular loop may have occurred among ritual practices and symbolic activity to deal with a novel culturally-mediated world. However, we suggest that the compulsion to action patterns repetition, typical of all rituals, has a genetically inborn motor foundation, thus precognitive and pre-symbolic. Rooted in such phylogenetically conserved motor structure (proximate causes), the evolution of cognitive and symbolic capacities have generated the complexity of human rituals, though maintaining the original adaptive function (ultimate causes) to cope with unpredictable environments
Testosterone, Cortisol and Empathy: Evidence for the Dual-Hormone Hypothesis
No full textThe dual hormone hypothesis posits that basal cortisol and testosterone have a joint effect on motivational and behavioral systems implicated in dominance and aggression, such that traits generally associated with high testosterone manifest more in individuals with low basal cortisol levels. Whether this hypothesis applies to behavioral systems other than dominance remains unclear. In the present study, we investigated the association between basal testosterone, basal cortisol, and empathy in a large population of MBA students. Empathy was assessed with a short version of the Davis’s Interpersonal Reactivity Index and with the Reading the Mind in the Eyes Test (RMET). Higher testosterone was predictive of lower empathy scores among men and women with low basal cortisol, while this association was reversed among individuals with high cortisol levels. In other words, a high-testosterone profile was found to be predictive of both high and low empathic dispositions depending on the concomitant HPA state. The effect was limited to self-reported empathy as no association was found with the RMET. This pattern of results, which emerged when data for men and women were analyzed together, remained significant only for men when analyses were run separately for the two sexes. These results add empathy to the list of behaviors regulated by the joint action of testosterone and cortisol, as outlined by the dual hormone hypothesis
Vardenafil Long-Term Administration Improves Episodic Memory in Aging Female Mice
No full textAge-dependent cognitive decline is associated with a downregulation of the cyclic nucleotide cascade. Through their regulation of the cGMP pathway, phosphodiesterase 5 inhibitors have been proven to enhance episodic memory in rodents and mice and have been proposed as drugs with the potential to counteract aging-dependent cognitive and neurodegenerative disorders. One caveat of this line of research is that these studies have been carried out in male rodents, leaving unknown their effects on female cognition. With the present study, we aim to fill this methodological gap. Twenty-four-month-old female mice were exposed to a continuous 33-day treatment with 2 mg/kg of Vardenafil and tested in the object recognition test, the elevated plus maze, and the open field test. The results show that, compared to females from the control group, Vardenafil-exposed females showed higher discrimination between familiar and novel objects compared to controls both at 1 h and 24 h delays, indicating that Vardenafil enhances episodic memory. No effects of Vardenafil on anxiety-like behaviors were found
The relevance of the evolutionary approach for understanding health and disease of the human body and mind
No full text: Ultimate and proximate levels of analysis offer synergistic explanations can improve the search for causes of disease and their cures. Here we review how several principles of evolutionary biology such as historical contingencies, mismatches, trade-offs, sexual selection and genomic conflict are applied to problems in medicine and psychiatry. The application of evolutionary principles to many other domains of medicine, among them mental disorders, have not received the same reception from preclinical and clinical researchers. The lack of a well-coordinated interdisciplinarity may be one reason for the slow application of evolutionary principles to biomedicine and psychiatry. This is exemplified by the case of ethopharmacology, an evolutionary approach to psychopharmacology strongly proposed and applied by ethologists but apparently unknown to many evolutionary minded scholars. Another reason has to do with the lack of efforts from many medical schools to integrate evolution and its principles in their curriculum studiorum. Interestingly, this Darwinian approach is generating an important evolutionary epistemology for the study of body and human mind health and diseases
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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