Although the concept of allostasis was proposed some 30 years ago, doubts persist about its precise meaning and whether it is useful. Here we review the concept in the context of recent studies as a ...strategy to efficiently regulate physiology and behavior. The brain, sensing the internal and external milieu, and consulting its database, predicts what is likely to be needed; then, it computes the best response. The brain rewards a better-than-predicted result with a pulse of dopamine, thereby encouraging the organism to learn effective regulatory behaviors. The brain, by prioritizing behaviors and dynamically adjusting the flows of energy and nutrients, reduces costly errors and exploits more opportunities. Despite significant costs of computation, allostasis pays off and can now be recognized as a core principle of organismal design.
Allostasis – brain-centered predictive regulation – starts with a hypothalamic clock that synchronizes clocks in every tissue.On this diurnal cycle of metabolic variation, the brain superimposes an episodic rest–activity cycle that coordinates change in key systems (respiration, heart rate, blood pressure, body temperature, and physical activity).The brain predicts upcoming needs for food, water, salt, warmth, or cooling and satisfies them by adjusting physiology and behavior to prevent errors that would require homeostatic correction.The brain rewards a better-than-predicted result with a pulse of dopamine, thereby encouraging the organism to learn effective regulatory behaviors.
Glucocorticoids and corticotropin releasing hormone (CRH) underlie the physiology of change and adaptation. Both the steroid and peptide are quite ancient. The genes that underlie the production of ...these information molecules stretch back millions of years. The regulatory mechanisms of glucocorticoids have both restraining and enhancing capabilities on CRH gene expression. While restraint of CRH by glucocorticoids is a fundamental physiological feature of limiting CRH expression from over-use and exhaustion, CRH is also enhanced by glucocorticoids at both the level of extra-hypothalamic CRH sites and at the level of the placenta and fetal programming in the brain. This latter function of glucocorticoids increasing CRH gene expression underlies the physiology of change that underlies diverse adaptive functions.
Effort Schulkin, Jay
2007, 2020, 2006, 2020-08-26
eBook
Earlier views associated cognition with the cortex, and effort with sub-cortical, non-cognitive structures. In this intriguing volume, Jay Schulkin explains an emerging perspective, that cognition ...runs throughout the central nervous system, and the perceptual/effector systems are pregnant with cognitive resources. One neurotransmitter, dopamine, underlies the diverse tasks that require effort, or the will. As Schulkin notes, one adaptation is to pre-commit oneself to future recursive actions consistent with one’s plans. Diverse brain regions are tied to the conflicts of competing interests that require willpower to persevere towards our longer-term goals. While it is debatable to what extent we are conscious of our willpower and our causal efficacy, the concept of the will is a fundamental category in understanding our mental architecture and is also a piece of our evolutionary history.
Cognitive scientists, neuroscientists, psychobiologists, evolutionary psychologists, philosophers, social psychologists, and anyone curious about how humans persist will be interested in Effort.
Running is not unique to humans, but it is seemingly a basic human capacity. This article addresses the evolutionary origins of humans running long distances, the basic physical capability of ...running, and the neurogenesis of aerobic fitness. This article more specifically speaks to the conditions that set the stage for the act of running, and then looks at brain expression, and longer-term consequences of running within a context of specific morphological features and diverse information molecules that participate in our capacity for running and sport. While causal factors are not known, we do know that physiological factors are involved in running and underlie neural function. Multiple themes about running are discussed in this article, including neurogenesis, neural plasticity, and memory enhancement. Aerobic exercise increases anterior hippocampus size. This expansion is linked to the improvement of memory, which reflects the improvement of learning as a function of running activity in animal studies. Higher fitness is associated with greater expansion, not only of the hippocampus, but of several other brain regions.
Social regulation of the internal milieu is a fundamental behavioral adaptation. Cephalic capability is reflected by anticipatory behaviors to serve systemic physiological regulation. Homeostatic ...regulation, a dominant perspective, reflects reactive responses; allostatic regulation, the physiology of change, emphasizes longer-term anticipatory, and feedforward systems. Steroids, such as cortisol, and peptides such as corticotrophin releasing hormone are but one example of such anticipatory regulatory systems. The concept of "allostasis" is in part to take account of anticipatory control amidst diverse forms of adaptation underlying this regulatory adaptation that supports social contact and the internal milieu.
Human beings are susceptible to sustained weight gain in the modern environment. Although both men and women can get fat, they get fat in different ways, and suffer different consequences. We review ...differences between men and women in the incidence of obesity, fat deposition patterns, fat metabolism, and the health consequences of obesity, and examine potential evolutionary explanations for these differences. Women generally have a larger proportion of body mass as fat, and are more likely to deposit fat subcutaneously and on their lower extremities; men are more likely to deposit fat in the abdominal region. Excess adipose tissue in the abdominal region, especially visceral fat, is associated with more health risks. Women have higher rates of reuptake of NEFA into adipose tissue; however, they also have higher rates of fat oxidation during prolonged exercise. Oestrogen appears to underlie many of these differences. Women bear higher nutrient costs during reproduction. Fat and fertility are linked in women, through leptin. Low leptin levels reduce fertility. Ovarian function of adult women is associated with their fatness at birth. In our evolutionary past food insecurity was a frequent occurrence. Women would have benefited from an increased ability to store fat in easily metabolisable depots. We suggest that the pattern of central obesity, more commonly seen in men, is not adaptive, but rather reflects the genetic drift hypothesis of human susceptibility to obesity. Female obesity, with excess adiposity in the lower extremities, reflects an exaggeration of an adaptation for female reproductive success.
Objective To identify gaps in polycystic ovary syndrome (PCOS) knowledge and practice patterns among physicians in North America in response to significant dissatisfaction identified among women with ...PCOS regarding their diagnosis and treatment experience. Design Online survey conducted via American College of Obstetrics and Gynecology of gynecologists (ObGyn) and American Society of Reproductive Medicine of reproductive endocrinologists (REI-ObGyn) in 2015–16. Setting Not applicable. Patient(s) None. Intervention(s) None. Main Outcome Measure(s) Diagnostic criteria used, key features of PCOS, management practices. Result(s) Of the 630 surveys completed, 70.2% were ObGyn and 64.4% were females. Overall 27.7% respondents did not know which PCOS diagnostic criteria they used. In a multivariable analysis including physician type, age, gender, and number of patients with PCOS seen annually, REI-ObGyn were less likely compared with ObGyn to report not knowing which criteria they used (adjusted odds ratio, 0.08; 95% confidence interval, 0.04, 0.16). REI-ObGyn were more likely to use the Rotterdam criteria (odds ratio, 2.26; 95% confidence interval, 1.33, 3.82). The majority of respondents recognized the clinical features associated with PCOS; however, over one-third associated “cysts on ovaries” with PCOS. The majority of responders (>85%) were aware of cardiometabolic comorbidities; however, fewer ObGyn were aware of associated depression, anxiety disorders, and reduced quality of life. More REI-ObGyn recommended lifestyle changes compared with ObGyn (56.4% vs. 41.6%). Conclusion(s) Our large-scale PCOS survey, conducted in response to patient concerns regarding diagnosis and treatment, highlights opportunities for physician education. Focus areas include targeting knowledge of internationally accepted Rotterdam criteria and ensuring consistent care informed by evidence-based guidelines across the reproductive, metabolic, and psychological features of PCOS.
Corticotropin-releasing factor (CRF)-mediated mechanisms in the bed nucleus of the stria terminalis (BNST) have a pivotal role in stress-induced anxiety and hyperalgesia. Although CRF is known to ...activate two receptor subtypes, CRF1 and CRF2, attempts to delineate the specific role of each subtype in modulating anxiety and nociception have been inconsistent. Here we test the hypothesis that CRF1 and CRF2 receptor activation in the anteriolateral BNST (BNSTAL) facilitates divergent mechanisms modulating comorbid anxiety and hyperalgesia. Microinfusions of the specific antagonists CP376395 and Astressin2B into the BNSTAL were used to investigate CRF1 and CRF2 receptor functions, respectively. We found that CRF1 and CRF2 receptors in the BNSTAL had opposing effects on exploratory behavior in the elevated plus-maze, somatic mechanical threshold, and the autonomic and endocrine response to stress. However, CRF1 or CRF2 receptor antagonism in the BNSTAL revealed complementary roles in facilitating the acoustic startle and visceromotor reflexes. Our results suggest that the net effect of CRF1 and CRF2 receptor activation in the BNSTAL is pathway-dependent and provides important insight into the CRF receptor-associated circuitry that likely underpins stress-induced pathologies.
Children become oriented to the world, in part, by coming to understand something of the experiences of others. The facial expressions that people make are an avenue for understanding something about ...them, as are the diverse forms of bodily responses emitted and interpreted by individuals. People with autism often find bodily communications to be aversive, thereby limiting what they can learn from others during social interactions. The amygdala is an important area of the brain, amongst others, for integrating the internal milieu with the social ambiance. Individuals with autism consistently demonstrate dysregulation of amygdala function. Diverse regions of the amygdala, which contain neuropeptides, figure in the appraisal systems that underlie behavioral approach and avoidance responses. One neuropeptide linked to social recognition and approach behaviors is oxytocin (which is known to be decreased in autistic individuals) and another neuropeptide corticotropin releasing hormone is tied to avoidance behaviors. A neuroendocrine hypothesis is suggested to account for some of the features associated with autism.
Modern neuroscience is beginning to substantiate Darwin's notion that the roots of human morality lie in social instincts, present in several species. The role of primitive motivational–emotional ...systems in human morality still remains under-recognized, however. Based on recent experimental evidence and classic neuroanatomical data, we here portray a view of how “ancient” limbic–neurohumoral systems of social attachment and aversion are crucially involved in human moral behaviors, including altruism, empathic concern and aggression. Rather than being a mere evolutionary remnant of our ancestors, such limbic–neurohumoral systems are tightly integrated with cortical mechanisms to enable complex moral sentiments and values, which powerfully influence our choices in socio-cultural settings. Exploring the underlying mechanisms of human social attachment and aversion will provide new insights and foster novel experimental paradigms for the study of moral cognition and behavior.
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