Stress Affects the Health of Physiologically and Psychologically

Stress is very well known for just what it means: STRESS. Its effect on human beings from a local and a global standpoint is far greater than any of us imagine. Stress can overtake one’s body physically, mentally, emotionally, as well as behavioral aspects. This is not something to take lightly. This is actually very serious. If you notice, it’s not just older people that die this day and time with heart attacks, suicide, and things of this nature. People of all ages. Older people, younger people, and even really young people. Children, yes, I said children. Don’t automatically think that stress only affects older people that have lived a longer

However, invasive methods and stress causing techniques are still used in animal research today as evident in a study by Meaney et al. (2011) which involved both socially raising rats and isolating others. Further, the investigation involved the killing of the rats in order to obtain brain tissue for the study of differences in the development of the glucocorticoid receptor (GR) systems in various parts of the brain. The study found the GR was enhanced due to prolonged single stress exposure in the prefrontal cortex and the hippocampus. Early handling of the rats protected them against ongoing stress-induced of GR expression of the prefrontal cortex, but not in the hippocampus. The study highlights the importance that the early life upbringing

The brain develops in such a way that it leaves itself vulnerable to these negative influences. The prenatal brain develops an overabundance of neurons, some of which are then carefully eliminated before age 4 (5). In a process similar to this, the amount of synapses between neurons is built up during early childhood and then pruned back for the next 30 years of life (5). These two processes are both disturbed by elevated levels of stress hormones (5). The two centers of the brain with the most postnatal changes, including the growth of new neurons after birth, are the hippocampus, which is part of the limbic system, and the cerebellar vermis (6). The hippocampus is in charge of creating and retrieving memories, working together with the other parts of the limbic system, such as the amygdala, which records the emotions for each memory. The vermis controls the production and release of two of the catecholamine neurotransmitters, dopamine and norepinephrine (6). Both the vermis and the limbic system have higher concentrations of receptors for the stress hormone cortisol than anywhere else in the brain (6). Due to this fact, these still-developing areas are the most vulnerable to the damage done by elevated levels of stress hormones.

The research contributions of this project could greatly contribute to positive social change in the areas of clinical treatment and early intervention. By contributing to the knowledge and understanding of how types of stressors during certain periods of neuronal development create dysregulation in the hippocampus, the effectiveness of therapeutic interventions could significantly be improved. According to Dr. Perry (2009), when clinical interventions are linked specifically to the area where dysregulation originated, in this instance, to the injured area of the brain, treatment would be in alignment with the stages of neuronal development and interventions will become more precisely attuned with the innervating sources of dysfunction. Once

The PVT has shown to have implications in stress processing due to its diverse population of neurons, holding a variety of functions. People are still discovering more about the PVT and its roles, but it is important to be able to categorize the neurons directly involved in stress. To discover more, I worked with c-fos, a protein which is a promoter for previous neuronal activity for the two restraint-stress experiments. For the first experiment, I used immunohistochemistry to label neurons expressing c-fos in both control and restraint mice. The raw data shows that with restraint there is an increase of c-fos expression in the PVT. In addition, the stainings show that there are two groups of neurons activated during times

Several limbic brain regions, including prefrontal cortex, hippocampus, amygdala, and nucleus accumbens (NAc), have been implicated in mediating key symptoms of depression and anxiety (Keedwell et al., 2005; Krishnan and Nestler, 2008; Mayberg et al., 2005). Chronic exposure to physical or psychological stress impairs the structure and function of neurons in prefrontal cortex (Radley et al., 2006), hippocampus (Surget et al., 2011) and amygdala (Mozhui et al., 2010). These changes depend on de novo synthesis of proteins involved in neural and synaptic plasticity. Synaptic proteins such as synaptophysin (SYP) and drebrin play a critical role in synaptic plasticity (Aoki et al., 2009; Janz et al., 1999). SYP is a major integral protein of the synaptic vesicle membrane and is required for vesicle

Stress is defined as the symptom resulting from exposure to a situation or environment that is not normal for an animal resulting in the production of stress hormones, catecholamine’s and glucocorticoids, leading to changes in cardiovascular function, energy producing mechanisms, digestion, immunity and reproduction (Foreman, 1996).

They were then tested on the morris water maze and found the distance taken to travel and find the platform decreased from first trials to second trials indicating better short term spatial learning while the measurement in long term spatial learning the socially stressed rats were swimming longer distances to get to the platform between first and second sessions. Which suggests that long term spatial memory in the morris water maze was impaired. This experiments indicate that exposure to social insabilty stress only impaired long term spatial memory and not short term spatial memory in the morris water maze. This current study after rats were exposed to the stress were placed back into their housing with another rat that was also exposed to the stress procedure but exposure the rat may be some sort of coping mechanism for the rats and that might be as to why the stress didn’t effect short term spatial memory in the morris water maze. As well this study is focusing on social stress by isolating the rats but by exposing them to another rat in the same housing they were before exposure to the stress may make the rats bond as they both were exposed to the stress which could mitigate the prior stress exposure. In addition short term memory might not have been effected due to stresses ability to effect distinct memory systems

The research focuses on observing the mice in a hippocampus-dependent spatial learning task, the Active Place Avoidance Task, to show that adult-born immature neurons are necessary in order for a subject to successfully obtain spatial learning. This article is useful to the research topic as the same animal model is used for the observation of the importance of microglia on anxiety in rats. A limitation of the study is that the results obtained during the spatial recall portion of the study were not supported by previous studies on the role of immature neurons in the adult brain in spatial memory recall, and should be further investigated. Overall, the authors observed that immature, adult-born neurons are important in spatial task learning however, their presence does not appear to have a significant effect on the recall ability of the subjects following their depletion. This article does not form the basis of the research topic however, it is useful as the animal model created here is that which the research methods will be modifying for use.

Chronic stress is known to cause detrimental effect on various forms of learning and memory. The basolateral amygdala (BLA) plays a crucial role in modulation of stress and related physiological effects including learning. This study was designed to evaluate the effects of excitotoxic lesion and temporary inactivation of the BLA on chronic stress-induced hippocampal-dependent spatial learning using partially baited radial arm maze task. The principal neurons in the BLA were either ablated using ibotenic acid or temporary inactivated using lidocaine prior to chronic immobilization stress. Chronically stressed rats showed impaired spatial learning with declined percentage correct choices and enhanced reference memory errors. We also observed the enhanced working memory errors although it was not consistent during all the blocks. The neurotoxic lesion and temporary inactivation of the BLA prior to stress prevented the impaired spatial learning with an increase in percentage correct choices and reduction in reference memory errors compared to stress group. During the retention, lesion and inactivation of BLA prior to stress, was able to preclude the chronic stress-induced enhanced reference memory errors and poor performance. Interestingly, stress-induced spatial learning deficits were associated with enhanced plasma corticosterone levels, which were partially prevented by the neurotoxic lesion and temporary inactivation of the BLA. Further, the partial reductions in plasma corticosterone levels were correlated with prevention of spatial learning and memory deficits. These results demonstrate that amygdala modulates chronic

The anatomical data suggest that there is widespread connectivity between amygdala and hippocampus, which is crucially affected during chronic stress. In contrast to hippocampus, amygdala positively regulates the HPA axis and undergoes hypertrophy following stress (vyas). The dendritic hypertrophy of amygdala especially in BLA has been observed during chronic stress. Interestingly, the excitotoxic or electrical lesion of amygdala prevents the stress-induced analgesia (Helmstetter, 1992), gastric ulceration (see in kim and diamond paper), anxiogenesis (Adamec et al., 1999) and spatial learning deficits (kim and diamond 2001). Additionally excitotoxic lesion of BLA prevented the stress-induced declined LTP in Schaffer collateral–commissural CA1 region of hippocampus (Kim and diamond 2001).The BLA lesion also blocked the deleterious effects of adrenalectomy and dexamethasone administration (Roozendaal et al., 1996, Roozendaal et al., 1998 and McGaugh, 2000). (Kim et al., 2001 and Kim et al.,

Stress can be broadly defined as any stimulus that disrupts homeostasis, with the stress response referring to physiological and behavioral reactions to such a stimulus (Selye, 1950).In vertebrates the stress response is an evolutionary conservative process mediated by the HPA axis that allows organisms to respond rapidly to unpredictable changes in their environment. It is initiated when higher brain centers perceive endogenous or exogenous noxious stimuli that threaten homeostasis and culminates in the release of glucocorticoids from the adrenal cortex. Elevated levels of circulating glucocorticoids exert a variety of catabolic, antireproductive, anti-growth, and immunosuppressive effects that mobilize and repartition under detailed organisms

Besides NPY, there are other neurobiological mechanisms that are believed to play a role in resilience. One factor, the brain-derived neurotrophic factor (BDNF), is important in studying stress responses. BDNF is a nerve growth factor that has been observed to be affected by stress. The BDNF expressed in the hippocampus decreases when exposed to stress, but in the nucleus accumbens, stress increases BDNF levels. (Feder, 2009) A study on BDNF levels in rats exposed to chronic stress established there was a relationship between hippocampal BDNF expression and resilience to chronic stress. (Taliaz, 2011)

Psychological stress is pressure placed on a person to adapt, cope, or adjust to a situation (Rathus, 2016, p.284). The result of prolonged stress can affect a person’s mood, pleasure experience, and have harmful effects on physical health (Rathus, 2016, p.284). Society in the twenty first century places high demands on people. Technology makes it very difficult to separate work life, school life, and home life. Today, society places a high value on a busy lifestyle for individuals. For example, many places of business are open twenty-four hours a day. In addition to societal pressures, attending a university adds to the stressors a person may experience. Going to school not only includes classroom time but it also includes homework,

Stress can influence the way the brain develops. During, fetal brain development, a very long process starts after the tenth gestational week when organs, begin to form, during this time the body is extremely vulnerable to the excessive maternal stress hormones which can change the cognitive function and behavior of the baby. (Lefmann,2014) The hippocampus is related to memory and