Animal models have made numerous progresses in the last century. This type of research has made a difference in the way we look at psychological issues such as depression. This paper is a review of the literature on animal models of depression. The issue of what advances have been made will be explored. The effects of serotonin on many issues have been studied. In this paper stress, learning, memory, brain derived neurotrophic factor, ovarian hormone withdrawal, and effects of certain drugs will be looked at. Let’s look at stress and serotonin first.
Stress
A study done by Grippo, Sullivan, Damjanoska and colleages (2004) shows that chronic mild stress provokes behavioral and physiological changes and may change serotonin receptor function in rats. In this study sixty four Sprague-Dawley rats were used. Half were male and the other half were female. The following stimuli were used as stressors which include:
Continuous light for 2 12 hour periods
Forty degree tilt along vertical axis of cage for 6 hour period
Paired housing for a 16 hour period and 4 hour period
Damp bedding with 300 mL water spilled on bedding for 16 hour period
Water deprivation for 16 hour period
Empty water bottle following 16 hour water deprivation for 1 hour
Stroboscopic light with 300 flashes a minute for a 6 hour period and 4 hour period
White noise at approximately 90 dB for 4 hour period of continuous noise and a 3 hour period with random intermittent noise
All the stressors were given over a period of one week, and randomly presented for 3 additional weeks for a total of 4 week trial. All the rats were injected with a receptor agonist and were decapitated 15 minutes after the injection for the trunk blood. The 4 week trial resulted in the rats showing signs of depression, and satisfied adrenocorticotropic hormone (ACTH) responses to the receptor agonist. The trials also sparked a lack of pleasure in both male and female rats.
Another studied related to stress was done by Gregus, Wintink, David and Lalynchik (2005). This study looked at corticosterone injections and stress and how this relates to depression. Sixty naïve Long-Evans male rats were used. The rats were randomly assigned to 4 groups and were given corticosterone injections (CORT), vehicle injections, repeated restraint stress and repeated handling. These treatments were given for 21 days. The CORT group and vehicle group were given injections at random times during the light and dark cycles.
Munoz was considered medically brain dead. She did not have any noted brain or brain stem activity. This meant that Marlise’s rights were terminated. The rights, then, should remain with the fetus, as it was considered alive. The hospital acting as a surrogate as the patient was unable to let his or her needs be known. Although the fetus had “abnormalitieis” didn’t mean that the fetus’s life was not worth living. Whether this is considered murder is far reaching, in my opinion. We should continue to preserve the life of the baby, whether it is handicap or not. We cannot preserve the life of Marlise, because there is no life to preserve. Taking Marlise off the support means that her own body will be unable to maintain life. What happened to the sanctity of the baby’s life is this particular
Although historically depression has been considered a character condition, evidence has accumulated suggesting the role of a biological substrate, namely serotonin, in subgroups of depressed patients. This accumulated evidence supports the indoleamine hypothesis of depression, which suggests that major depression results from a deficiency of available serotonin or inefficient serotonin. (16). We see that depletions of serotonin from certain regions of the brain such as the hypothalamus, amygdala, and cortical areas involved in cognition and other high processes, can have a great impact in contributing to depression.
To a great extent, stress can be a helpful response, especially for prehistoric humans. During this era, our species needed to react quickly to outside stimuli through a response of “fight or flight”. Through stress, certain hormones are released to help the individual resist the stressor, which may have meant running away from a natural predator. Thus, stress is a positive response that ensures the survival of the species. However, stress over a prolonged period of time causes exhaustion in the individual. Consequently, although stress can be helpful for individuals today, many often experience chronic stress, inflicting varying degrees of damage to their bodies.
One of the most common sensations in all humans is that of stress. This may be induced by everything from more serious life-or-death situations, to more mundane concern over deadlines or relationships. The body has a somewhat graded response to these events depending on their severity, but its response, regardless of severity, is rooted in the same neuroendocrine response of the hypothalamic-pituitary-adrenal axis (HPA Axis). This response is characterized by the feedback interactions and influencing of three of the bodies endocrine glands: the hypothalamus, the pituitary gland, and the adrenal glands (1). In response to stress, the hypothalamus releases corticotropin-releasing factor (CRF), which travels through the hypophyseal portal system
The receptors involved in serotonin are 5-HT pre and postsynaptic receptors. Understanding the mechanism of serotonin aids in various treatments for depression. For example, understanding the levels of cerebrospinal fluid regarding serotonin has significantly aided scientists in understanding the root cause for depression. These levels are much lower in depressed individuals, as well as depressed individuals who attempted suicide (Holtzeimer et al., 2006). In addition to lower cerebrospinal fluid metabolites of serotonin, abnormalities with serotonin binding and reduced amounts of tryptophan have also lead to an understanding of the causes of depression.
History has caused a shift from psychological treatment of mental health to a biological and more specifically pharmacological approach to treatment. Boniwell and Rostron, (2010) suggested that the latter approach can provide a better understanding for mental illness. For example, understanding the biological function of stress response, has allowed specialists to develop mechanisms that can control the level of chemicals in the body, thus control development of mental illnesses (Datta,
The One Minute Manager by Kenneth Blanchard, Ph.D. and Spencer Johnson, M.D., seems like a practical simple plan on managing people and there for other areas of one’s life, however I must admit I am a little skeptical. The three philosophies do make sense especially once analogies are used to put them into more simple terms. Being in the work force for more than fourteen years I have witnessed many types of mangers. I have worked for hostile managers, calm caring managers and managers who fit somewhere in between. My skepticism with this theory is simply applying its use. On paper this method sounds great and makes a lot of key points, but again after seeing first hand the types of people in management positions I think the challenge comes from undoing current behavior. My observation of people in general, is that they unwelcome change and find it uncomfortable.
In The One Minute Manager, Kenneth Blanchard and Spencer Johnson outline three vital secrets to guarantee efficient and productive management. The techniques of one minute management involve a young man seeking the ideal management and leadership skills. The One Minute manager places a lot of emphasis on focus, rather than being a one minute manager. Blanchard & Spencer (2005) consider the one minute manager as a vulnerable leader, who is mostly spoken of by his or her subordinates; however, the identified three secrets are the key to successful management and leadership. The book was first published during the 1980s, which makes it a classic material in the business context. The comprises of a business parable of sorts, wherein a fictional
The One Minute Manager is a book written by Ken Blanchard and Spencer Johnson. It is a powerful tool not only for managing people but for modifying our behaviors to be a better person. It is a story of a young man and a successful manager who has effectively manage his subordinates and able to influence them on a One Minute Management.
Reverse supply chain refers to the movement of goods from customer to vendor. This is the reverse of the traditional supply chain movement of goods from vendor to customer. Reverse logistics is the process of planning, implementing and controlling the efficient and effective inbound flow and storage of secondary goods and related information for the purpose of recovering value or proper disposal. There are various types of reverse supply chains, and they arise at different stages of the product cycle; however, most return supply chains are organized to carry out five key processes:
For example, glucocorticoids are released in response to situations that are not normally regarded as stressful, including courtship, copulation and hunting. (Mostl & Palm) Selye noted that a principal characteristic of this response is an elevation in cortisol level. As a result of this early work and of more recent laboratory-based research, cortisol is now often regarded as a "stress hormone" and as an objective marker of stress (Pollard 1995) Cortisol and corticosterone have been used for assessing physical and psychological stress in variety of animals and matrices such as blood, bird eggs, feces, saliva, feathers, liver and gonad tissue, and hair. (To et al) During times when an organism undergoes physiologic duress, cortisol acts to mobilize energy stores and modulate the immune system. (Russell) High cortisol level has potential deleterious effects. For example it cause prolonged wound healing as well as a significant degree of cognitive impairment (Karlen et al. 2011) Cortisol assistant organism to cope effectively with threat by enhancing organisms ability to respond to homeostatic challenge and assisting the body to defend itself against infectious agents. (Sharpley et al
Somni, R. W., Crismon, M. L. & Bowden, C. L. Fluoxetine: a serotonin-specific, second-generation antidepressant, Pharmacotherapy, Jan.-Feb. 1987, 7(1): 1-15.
In my memory, my grandparent’s house looks lively and surrounded by garden. The front door of the house was connected with the gate of the garden by cobblestone. Along both
The common effects of stress on the body are “headache, muscle tension or pain, chest pain, fatigue, stomach upset, and sleep problems.” (Mayo clinic staff). Also, there other stress symptoms. The stress effect not just on the heath of the body, but also on the mood and emotions. Therefore, the stress symptoms on the mood are “restlessness, lack of motivation or focus, irritability or anger, and sadness or depression” (Mayo clinic staff). When the stress will hurt the person physically, mentally, and emotionally. The human being naturally will look and search for pain reliever. Some people will look for a good treatment, but the other will not care if the treatment is good or bad, they just want a pain reliever. So, there research will deviates to wrong paths. For example they will use the drugs to reduce their pain or someone will not use these really bad stuff, but they may acquire bad habit or do something else will effect badly on the body and mood. Therefore, the effect of the stress on the behavior are “drug or alcohol abuse, tobacco use, social withdrawal, angry outbursts, and overeating or undereating.” (Mayo clinic staff). There are more other effects on the behavior. Actually, the stress symptoms on the behavior depends on the personality of the
Karlberg, J., Karlberg, P., Klackenber-Larsson, I., Lambert, W.W., and MacEvoy, B. (1987). The relation of stress hormone excretion to type A behavior and to