Stress physiology

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Stress Physiology and Behavior Problems

Stress Physiology and Behavior Problems

The findings also have policy implications, particularly for treatment evaluation research. Frist, as shown in the findings, individuals have different susceptibility in their stress physiology to environmental influences. Understanding what biological features moderate the intervention outcome is beneficial because we can better evaluate the efficacy of interventions and design interventions catered to subgroups of individuals with distinctive biological characteristics. There are some great attempts in recent years of investigating treatment moderators. For example, Albert and colleagues (2015) identified sources of genomic variations in the effects of the Fast Track Randomized Control Intervention Trial. The Fast Track Intervention is a ten-year long randomized controlled prevention program designed in part to improve emotion regulation and self-control in the context of social stress with the ultimate goal to reducing persistent externalizing problems. Albert and colleagues found that variants of the gene NRC31, a gene that encodes glucocorticoid receptor protein for inhibitory signaling in the HPA axis, moderate the treatment outcomes of Fast Track Intervention. This finding highlights the key role that HPA axis plays in influencing individuals’ response to environment.
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The effect of working on-call on stress physiology and sleep: A systematic review

The effect of working on-call on stress physiology and sleep: A systematic review

On-call work is becoming an increasingly common work pattern, yet the human impacts of this type of work are not well established. Given the likelihood of calls to occur outside regular work hours, it is important to consider the potential impact of working on-call on stress physiology and sleep. The aims of this review were to collate and evaluate evidence on the effects of working on-call from home on stress physiology and sleep. A systematic search of Ebsco Host, Embase, Web of Science, Scopus and ScienceDirect was conducted. Search terms included: on-call, on call, standby, sleep, cortisol, heart rate, adrenaline,
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Upper thermal limits of growth in brook trout and their relationship to stress physiology

Upper thermal limits of growth in brook trout and their relationship to stress physiology

of 6.5 – 20°C when compared with more moderate daily oscillations and constant temperature controls. However, redband trout subjected to 8°C oscillations of 8 – 16°C or 18 – 26°C did not exhibit elevated plasma cortisol levels (Cassinelli and Moffitt, 2010). It is also possible that there was an endocrine stress response induced during our growth study and that we missed the signal due to the timing of our sampling. In Atlantic salmon, plasma cortisol and glucose have been shown to return to baseline levels within hours following an acute crowding stressor (Carey and McCormick, 1998). In our growth study, we sampled fish in the morning when water temperatures had been below 21°C for at least 9 h, potentially giving them time to recover from any thermal stress experienced during the previous day. However, in our acute exposures we sampled after 1 h at peak temperatures and still did not observe elevated plasma cortisol or glucose, suggesting that these oscillating temperature treatments were not severe or long enough to induce an endocrine stress response. It is possible that plasma cortisol will only be elevated (or detectably different) when temperatures are high enough to induce severe and long-term reductions in food consumption and growth. It should also be noted that there are diurnal (circadian) rhythms in plasma cortisol in fish that are independent of temperature (Audet and Claireaux, 1992) that may have affected our ability to detect temperature impacts on cortisol. In addition to thermal impacts on brook trout growth and stress physiology we also explored the influence of elevated temperature on osmoregulation. Gill NKA activity (50%) and abundance (80%) decreased with temperature and were lowest at 24°C. The greater impact on abundance than activity suggests that the activity per unit molecule NKA is greater at elevated temperatures. Despite this, there were no differences in plasma Cl – levels in our temperature treatments, and no effect of oscillating temperature on gill NKA activity. Elevated temperature has been shown to reduce the length of the smolt window, as characterized by decreased gill NKA activity and seawater tolerance, in anadromous salmonids (McCormick et al., 1996, 1999), although this may be more related to temperature impacts on development than it is to temperature effects on osmoregulation per se. Similarly, elevated temperature also reduces survival and gill NKA activity in sockeye salmon during their spawning migration (Crossin et al., 2008). An inverse relationship between temperature and gill NKA activity has been observed in cod (Staurnes et al., 1994), halibut (Jonassen et al., 1999) and pupfish (Stuenkel and Hillyard, 1980), but not in turbot (Burel et al., 1996). It is plausible that changes in enzyme kinetics or alterations in behavior at elevated temperatures lessen the demand for both gill NKA activity and abundance, although more exploration in these areas is clearly needed.
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Surviving in a frozen desert: environmental stress physiology of terrestrial Antarctic arthropods

Surviving in a frozen desert: environmental stress physiology of terrestrial Antarctic arthropods

Abiotic stress is one of the primary constraints limiting the range and success of arthropods, and nowhere is this more apparent than Antarctica. Antarctic arthropods have evolved a suite of adaptations to cope with extremes in temperature and water availability. Here, we review the current state of knowledge regarding the environmental physiology of terrestrial arthropods in Antarctica. To survive low temperatures, mites and Collembola are freeze-intolerant and rely on deep supercooling, in some cases supercooling below –30°C. Also, some of these microarthropods are capable of cryoprotective dehydration to extend their supercooling capacity and reduce the risk of freezing. In contrast, the two best-studied Antarctic insects, the midges Belgica antarctica and Eretmoptera murphyi, are freeze- tolerant year-round and rely on both seasonal and rapid cold- hardening to cope with decreases in temperature. A common theme among Antarctic arthropods is extreme tolerance of dehydration; some accomplish this by cuticular mechanisms to minimize water loss across their cuticle, while a majority have highly permeable cuticles but tolerate upwards of 50–70% loss of body water. Molecular studies of Antarctic arthropod stress physiology are still in their infancy, but several recent studies are beginning to shed light on the underlying mechanisms that govern extreme stress tolerance. Some common themes that are emerging include the importance of cuticular and cytoskeletal rearrangements, heat shock proteins, metabolic restructuring and cell recycling pathways as key mediators of cold and water stress in the Antarctic.
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Similarities in stress physiology among patients with chronic pain and headache disorders: evidence for a common pathophysiological mechanism?

Similarities in stress physiology among patients with chronic pain and headache disorders: evidence for a common pathophysiological mechanism?

In the recovery period, FMS and SNP patients had more vasoconstriction than migraine patients. Previously, we had reported increased vasoconstriction in TTH patients compared to migraine patients in the recovery period after stress [32]. Chronic pain patients also continued to have decrease in BF during the recovery period, while the episodic pain/control group seemed to stabilise. This finding is especially interesting in conjunction with the theoretical models of Eriksen and Ursin [19, 20] and McEwen [21, 22]. Both these models focus on subjects’ inability to turn off a stress response, i.e. a lack of recovery, as a cause of health complaints. Repeated inability to recover from stress, for instance caused by the subject’s inability to cope with the demands in his/her working environment, may create a vicious circle resulting in pain or other health complaints in some subjects. This model is supported by a study of Sluiter et al., who reported a connection between the need for recovery from work-related fatigue (presumably caused by stress and other work-environmental factors) and subjective health
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Physiological trade offs in self maintenance: plumage molt and stress physiology in birds

Physiological trade offs in self maintenance: plumage molt and stress physiology in birds

Behavioral, energetic or resource-based conflicts between maintenance processes such as molt and the stress response may have influenced the evolution of life cycle schedules. Species dealing with high exposure to environmental challenges may, for example, have been forced to minimize the rate of resource allocation to feather growth in order to maintain full hormonal stress responsiveness. Red crossbills (Loxia curvirostra) and zebra finches (Taeniopygia guttata) are two passerine species that exhibit protracted molts. They are both temporally opportunistic breeders that experience relatively high environmental unpredictability. Thus, if a trade-off is mediating investment in molt and hormonal stress responsiveness, we predict that both species will show little suppression of CORT secretion during feather molt. However, zebra finches in different parts of Australia encounter different degrees of seasonality and resource predictability. If stress suppression is either locally adaptable or relatively flexible, then we expect zebra finch populations in more predictable habitats to show greater stress response suppression and/or faster molts. To test these predictions we measured baseline and induced levels of CORT during and outside molt in free-living red crossbills and zebra finches. We also measured CBG to determine whether binding protein capacity and thereby unbound, or free, CORT concentrations change during molt. Finally, to determine whether a relationship exists between molt duration and CORT secretion we then calculated phylogenetically independent contrasts of the 13 species for which data are now available. We also formalize several hypotheses for the resulting patterns, including energetic, molecular and behavioral trade-offs, and discuss these results in the context of these hypotheses as well as possible non-trade-off alternatives.
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Working Memory Impairments in Chromosome 22q11.2 Deletion Syndrome: The Roles of Anxiety and Stress Physiology

Working Memory Impairments in Chromosome 22q11.2 Deletion Syndrome: The Roles of Anxiety and Stress Physiology

deficits. Consistent exposure to stressful stimuli leads to increased blood pressure and heart rate will later lead to heart disease, hypertension, and a weakened immune system, among other outcomes (Baum & Posluszny, 1999; McEwen, 2003). Cognitively, increased allostatic load is associated with synaptic and dendritic changes and suppressed neurogenesis, which results in a weakened ability for the body to properly respond to stressors (Arnsten, 2009; Brown, Rush, & McEwen, 1999; Juster, McEwen, & Lupien, 2010). Interleukin 6 (IL-6), a pro-inflammatory cytokine, acts to incite immune response after trauma. It plays a crucial role in preparing the body to react to illness as it mediates fever by increasing the body’s temperature. In response to chronic stress exposure, though, the body overproduces IL-6. As an individual increases in age, this exaggerated production is associated with osteoporosis, arthritis, type 2 diabetes, and certain cancers (Kiecolt-Glaser et al., 2003). Inflammation is seen in a variety of patient populations including schizophrenia, autism spectrum disorder, Alzheimer’s disease, and in those with chronic anxiety, depression, and stress (de Pablos et al., 2006; Maes et al., 1998; Rojo,
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Extending the 2% rule: the effects of heavy internal tags on stress physiology, swimming performance, and growth in brook trout

Extending the 2% rule: the effects of heavy internal tags on stress physiology, swimming performance, and growth in brook trout

Beyond the challenges of tag attachment, the primary concern for researchers using biotelemetry is tag burden, the ratio of transmitter weight to fish weight [5]. Most researchers adhere to the guideline that tags should not weigh greater than 2% of the body weight of the fish in air [3], a practice that is often referred to as the ‘2% rule’. Despite its ubiquity, the 2% rule is not fully credited to a single author or citation and appears to be the result of a general consensus based on several studies of buoy- ancy control in fishes published between 1966 and 1984. Initial morphological studies reported that the swim bladder of typical freshwater teleosts is about 7% of the body volume, and that these fish have the capacity to ad- just approximately 25% of that total volume [6]. Based on these findings, it was argued that the maximum tag weight in water should not exceed 1.75% of the body weight of the fish, reflecting the 25% adjustment volume of the total 7% swim bladder volume [7]. Experimental evi- dence indicated that bluegills (Lepomis cyanellus) could maintain neutral buoyancy when burdened with weights of up to 2% of the weight the fish in air [8], and subsequent authors argued that weights of transmitters in water should be less than 1.5% of the fish weight [9]. In 1983, Winter [10] recommended that as a rule of thumb, fish should not be tagged with transmitters that weighed more than 1.25% in water or 2% in air of the fish’s weight out of water. In support of this guideline, Mellas et al. [4] reported no dif- ference in swimming performance of rainbow trout im- planted with tags that were <1.7% body weight. Though intended as a ‘rule of thumb’ , this recommendation was republished by the American Fisheries Society in 1996 [11] and is now widely accepted and used in many studies. Despite its ubiquity, several studies have challenged the 2% rule and shown that much heavier tags can be used without detriment to the physiology or swimming performance of the fish. In one study of juvenile rainbow trout (Oncorhynchus mykiss), intraperitoneal implantation of transmitters that weighed 6% to 12% of the fish’s body weight in air did not adversely affect the critical swimming velocity [12]; however, physiological measures of stress were not quantified. Additionally, studies of pre-smolt coho salmon (O. kisutch) tagged with internal tags weigh- ing up to 8% body mass and observed for 300 days showed no significant effect of tag size on growth, swimming per- formance, or likelihood of survival in the wild [13].
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SHODHANA CHIKITSA IN COMPARISON WITH STRESS PHYSIOLOGY    A BIOMEDICAL VIEW .......

SHODHANA CHIKITSA IN COMPARISON WITH STRESS PHYSIOLOGY A BIOMEDICAL VIEW .......

This concept can be elaborated under the purview of Stress which is defined as a physiological reaction by an organism to an uncomfortable or unfamiliar physical or psychological stimulus. This stress is of two kinds – Eustress and Distress 5 . The one whose outcome is a negative response is called Distress whereas the one capable of generating a positive beneficial response is called as Eustress. To be more precise, SC is a sort of Eustress which alerts the body’s corrective mechanisms by stimulating the controlling systems of the body, thereby, exhibiting their influence through the working systems of the body to achieve a normal homeostasis i.e., the state of normal cell health.
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A Review on Stress Physiology and Herbal Approaches of Treatment

A Review on Stress Physiology and Herbal Approaches of Treatment

Stress that is, any type of stimulus that challenges the organism‘s normal internal balance—induces a physiologic response involving a variety of hormones and other signaling molecules that act on, among other organs, the brain. The most recent research on the relationship between the mind and body involves research in the field of psych neuroendocrinology, which is the study of the relationship between the brain, thoughts and emotions, and the endocrine system. These studies demonstrate a connection between the central nervous system and the endocrine system that were until recently believed to act independently. The autonomic nervous system controls bodily functions which we are largely unaware of and do not consciously control. The part of the autonomic nervous system that is activated during emergencies is the sympathetic nervous system, which speeds up systems needed for survival. The other part of the autonomic nervous system, the parasympathetic nervous system, plays an opposing role. It mediates passive activities and promotes growth and energy storage. Parts of this system are also called into play during stress to slow down systems not required for survival. Ayurvedic literature mentions several herbs exerting favourable influence on brain function in general and memory in particular.
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Pre  and post natal stress in context: effects on the stress physiology in a precocial bird

Pre and post natal stress in context: effects on the stress physiology in a precocial bird

offspring HPA axis may be different from those caused by post- natal stress. While maternal pre-natal stress often results in HPA hyper-responsiveness, with pre-natally stressed offspring exhibiting enhanced and prolonged stress hormone release in response to stress (Henry et al., 1994; Barbazanges et al., 1996; Kapoor et al., 2006), post-natal exposure to stressors, such as ‘neonatal handling’, can produce dampened stress responsiveness (Levine, 1967; Meaney and Aitken, 1985; Vallée et al., 1996; Liu et al., 1997; Macrì et al., 2004). Importantly, several post-natal manipulations in rat pups are known to cause changes in the amount of maternal care provided by the dams, which, to a certain degree, can buffer or counteract the effects of previous pre- and post-natal stressors (Maccari et al., 1995; see also review by Macrì and Würbel, 2006). On the one hand, these data raise the question, surprisingly understudied, of interactive influences between pre- and post-natal experiences. On the other hand, they also draw attention to the difficulties in determining whether the observed effects are mediated by an altered maternal HPA axis, direct changes in the offspring HPA reactivity or an interaction of both, as has been recently proposed (Macrì and Würbel, 2006). Birds offer advantages over mammalian species in terms of experimentally manipulating pre- and post-natal environments, minimising interactions with the mother’s physiology (see reviews by Henriksen et al., 2011; Schoech et al., 2011; see also Spencer et al., 2009; Love and Williams, 2008). Precocial birds in captive conditions can be reared without post-natal maternal contact, thereby excluding the potential confounding factor of maternal care. Furthermore, avian and mammalian neuroendocrine systems are highly conserved (Wingfield, 2005a), facilitating comparative approaches in a more evolutionary framework (Groothuis et al., 2005). The few studies conducted in birds to date have demonstrated that pre
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Biology, physiology and gene expression of grasshopper Oedaleus asiaticus exposed to diet stress from plant secondary compounds

Biology, physiology and gene expression of grasshopper Oedaleus asiaticus exposed to diet stress from plant secondary compounds

We studied the role of plant primary and secondary metabolites in mediating plant-insect interactions by conducting a no-choice single-plant species field experiment to compare the suitability, enzyme activities, and gene expression of Oedaleus asiaticus grasshoppers feeding on four host and non- host plants with different chemical traits. O. asiaticus growth showed a positive relationship to food nutrition content and a negative relationship to secondary compounds content. Grasshopper amylase, chymotrypsin, and lipase activities were positively related to food starch, crude protein, and lipid content, respectively. Activity of cytochrome P450s, glutathione-S-transferase, and carboxylesterase were positively related to levels of secondary plant compounds. Gene expression of UDP-glucuronosyltransferase 2C1, cytochrome P450 6K1 were also positively related to secondary compounds content in the diet. Grasshoppers feeding on Artemisia frigida, a species with low nutrient content and a high level of secondary compounds, had reduced growth and digestive enzyme activity. They also had higher detoxification enzyme activity and gene expression compared to grasshoppers feeding on the grasses Cleistogenes squarrosa, Leymus chinensis, or Stipa krylovii. These results illustrated Oedaleus asiaticus adaptive responses to diet stress resulting from toxic chemicals, and support the hypothesis that nutritious food benefits insect growth, but plant secondary compounds are detrimental for insect growth.
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EFFECT OF SIMULATED WATER STRESS ON THE PHYSIOLOGY OF LEAF SENESCENCE IN THREE GENOTYPES OF COWPEA VIGNA UNGUICULATA (L.) WALP)

EFFECT OF SIMULATED WATER STRESS ON THE PHYSIOLOGY OF LEAF SENESCENCE IN THREE GENOTYPES OF COWPEA VIGNA UNGUICULATA (L.) WALP)

photosynthesis, root and nodule respiration, and relative water content and water retension in the leaves of water stress imposed at preflowering genotypes of Pigeon pea (Cajanus cajan L.), while Pic et al. (2002) studied the leaf senescence induced by mild water deficit and observed that this kind of induced senescence follows the same sequence of macroscopic, biochemical, and molecular events as monocarpic senescence in Pigeon pea. Recently Garg et al. (2004) studied the effect of water stress on six genotypes of moth bean (Vigna acontifolia) and compared the metabolic alterations among them. However, it is evident from the published literature that so far no such attempt has been made to elucidate the impact of drought condition on the physiology of leaf senescence in the varieties of cowpea. Hence the present investigation is undertaken with a view to elucidate the biochemical changes associated with the water stress induced leaf senescence in the three selected genotypes of cowpea.
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Adolescent Development Determines the Effects of Agonistic Social Stress on Rat Behavior and Locus Coeruleus Physiology

Adolescent Development Determines the Effects of Agonistic Social Stress on Rat Behavior and Locus Coeruleus Physiology

Bockstaele et al., 1997; Van Bockstaele et al., 2010). Curtis and colleagues have shown that one of the prominent functions of the mu-opioid system in the LC is to functionally counteract, or balance the post-synaptic effects of stress-induced CRF release. In an interesting study, they found that hypotensive stress initially caused an increase in LC firing rate, followed by suppression. If a CRF antagonist was locally applied to the LC during stress, the initial increase in LC discharge rate was blocked, but the post-stress inhibition component was amplified and prolonged. However, if naloxone, a mu-opioid receptor antagonist was applied instead of the CRF antagonist, the post- stress inhibition was selectively blocked and LC neurons took longer to return to baseline levels of firing when the stressor was terminated (Curtis et al., 2001). This counter-CRF effect is especially intriguing in light of the data presented in this thesis that social defeat increases CRF-induced LC activity only in early adolescent rats. Besides glucocorticoid regulation, another plausible mechanism for the loss of CRF influence in adulthood could be latent development of an opposing system, like the mu-opioids. However, this would only oppose the increase in tonic rate associated with CRF release and could not account for the increase in phasic response, suggesting that another system would be have to be involved.
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Effects of early nutritional stress on physiology, life histories and their trade offs in a model ectothermic vertebrate

Effects of early nutritional stress on physiology, life histories and their trade offs in a model ectothermic vertebrate

following a period of food restriction. Low-diet animals did not quite catch up in size with their normal-diet conspecifics. We found immediate, but not lasting, effects of early-life diet on immune function and physiological state. Traits in which the two sexes responded differently to early-life stress included mating success and long-term survival. Males differed in reproductive success in relation to early-life experiences such that low-diet males exhibited reduced success. Although females did not differ in their propensity to mate, low-diet females gave birth to smaller offspring. Early-life food restriction had long-term effects not only on female reproduction, but also on survival, with low-diet females exhibiting lower survival than their normal-diet conspecifics. Resource availability, especially during periods of development, is important in determining the life-history trajectory of an organism. It has been widely hypothesized that accelerated growth rates, particularly when following periods of reduced resource availability, may trade off with longevity (Metcalfe and Monaghan, 2001, 2003). Our results suggest that, at least for females, current reproduction may be prioritized over future survival when exposed to adverse early-life conditions such as resource limitation.
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Water Stress Mediated Changes in Morphology and Physiology of Gossypium arboreum (Var FDH-786)

Water Stress Mediated Changes in Morphology and Physiology of Gossypium arboreum (Var FDH-786)

It has been established that drought stress is a very important limiting factor at the initial phase of plant growth and establishment. It affects both elongation and expansion growth [9-11]. Stem length was significantly affected under water stress in potato [18], Abelmoschus esculentus, [12]. Water stress greatly suppresses cell expansion and cell growth due to the low turgor pressure. Osmotic regulation can enable the maintenance of cell turgor for survival or to assist plant growth under severe drought conditions in pearl millet [11]. The reduction in plant height was associated with a decline in the cell enlargement and more leaf senescence in A. esculentus under water stress [12]. The root dry weight was decreased under mild and severe water stress in Populus species [13]. An increase in root to shoot ratio under drought
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Physiology & Pharmacology Physiology 4730B: Cell Signaling in Tissue Injury & Repair

Physiology & Pharmacology Physiology 4730B: Cell Signaling in Tissue Injury & Repair

Cellular and molecular physiology is an exciting and rapidly changing area of biology. Physiology 4730B is a one-term half-course designed to introduce students to advanced concepts and current research focused on cell signaling pathways that regulate cellular function and promote survival, repair and regeneration. The models studied will include the nervous system and various peripheral systems and relevant pathologies with an emphasis on therapeutic approaches. Reference to published scientific literature will be used as appropriate. The format of the course will be a series of lectures on the selected topics introduced by two faculty members. Students are expected to be able to recall and critically evaluate facts, recognize general concepts, use new information to solve problems, be aware of the historical development of the research field, and be familiar with current literature and research methods. Students will also be responsible for presenting, critiquing and discussing research papers in group formats.
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The physiology of follicle selection

The physiology of follicle selection

During the luteal phase of the menstrual cycle, pre- ovulatory follicular development is curtailed because the corpus luteum, via its secretions of estrogen, progesterone and possibly in[r]

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Endocrinology and physiology of pseudocyesis

Endocrinology and physiology of pseudocyesis

Neuroendocrine/endocrine pathways of pseudocyesis Most pseudocyetic women suffer from mild to major depression, anxiety and/or emotional stress due to psychologic conflicts or needs, such as women who simultaneously wish for children and fear becoming pregnant (for reviews, see Small [31], O’Grady and Rosenthal [9] and Whelan and Stewart [88]) or women who have an overwhelming desire to become pregnant because of societal pressures [3,7]. In this context, we should mention that patients with major depression have a deficit in brain dopamine and norepinephrine activity [89], and increased sympathetic nervous system activity associated with a higher rate of entry to plasma of norepinephrine released from sympathetic nerves (norepinephrine spillover rate) [90,91] and elevated plasma levels of norepinephrine [92]. In rodents, chronic psycho- social stress is also associated with reduced brain dopamine and norepinephrine activity and elevated plasma levels of norepinephrine (for reviews, see Goddard et al. [93] and Rasheed and Alghasham [94]). PCOS women also show low dopamine hypothalamic tone (for review, see Hernández et al. [95]).
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Integrative Physiology

Integrative Physiology

Objective: To develop a clinically translatable therapy, we hypothesized that in a preclinical ovine model of myocardial infarction, the modified endothelial progenitor stem cell chemo[r]

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