How animal research has advanced the understanding of depression :: essays research papers

Animal models gull 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 report card is a review of the literature on animal models of depression. The issue of what advances have been made will be explored. The effect of serotonin on umpteen issues have been studied. In this paper dialect, learning, memory, brain derived neurotrophic factor, ovarian hormone withdrawal, and effects of certain drugs will be looked at. Lets look at stress and serotonin first.StressA study done by Grippo, Sullivan, Damjanoska and colleages (2004) shows that chronic mild stress provokes behavioral and physiological metamorphoses and may change serotonin receptor function in rats. In this study sixty four Sprague-Dawley rats were utilize. Half were virile and the other half were female. The following stimuli were used as stressors which includeContinuous light for 2 12 instant resultsForty d egree tilt along vertical axis of detain for 6 moment periodPaired housing for a 16 moment period and 4 hour periodDamp bed with 300 mL water spilled on bedding for 16 hour periodWater privation for 16 hour period put down water bottle following 16 hour water deprivation for 1 hourStroboscopic light with 300 flashes a minute for a 6 hour period and 4 hour period colour noise at approximately 90 dB for 4 hour period of continuous noise and a 3 hour period with random intermittent noiseAll the stressors were disposed over a period of one hebdomad, and helter-skelter presented for 3 additional weeks for a count of 4 week trial. All the rats were injected with a receptor agonist and were decapitate 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 nave 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.