Alterations in the Endocannabinoid System; an Animal Model of Depression
Alterations in the Endocannabinoid System; an Animal Model of Depression Depressive illness is widespread and exhibits a lifetime prevalence rate of 16% (Kessler et al. 2003). Depressive illnesses can be characterized by an array of disturbances, emotional behavior, memory, neuro-vegetative functions and hedonic processing. The neurobiological mechanisms subserving the development, manifestation and treatment of depression are complex, and there is ample evidence that disturbances in monoaminergic signaling, glucocorticoid activity and neurotrophic/neuroplastic processes are involved (Ressler and Nemeroff 2000; Holsboer 2000; Duman and Monteggia 2006; McEwen 2005). A wide range of people I know suffer from depression and currently use prescribed medication in order to alleviate the symptoms; for this reason, I chose this article. Cannabinoids are a diverse class of compounds that activate cannabinoid receptors CB1 and CB2. I want to explore the effect of cannabinoids on people who have been subjected to Chronic Unpredicted Stress (CUS). This CUS is one of the leading causes of depression in teenagers. This article really discovers the effects of cannabinoids on rats which have had a prolonged exposure to CUS. The colleagues tested Long-Evans rats who were 70 days old with an independent variable as the amount of cannabinoids used on a CUS induced rat and the dependent variable as the amount of depression the rats had. A main method the researchers used to analyze the depression in rats was their sexual activity. All the behavioral testing was performed during the middle of the third light cycle. They found that this resulted in a significant increase in CB1 receptor binding site density in the prefrontal cortex and a decrease in CB1 receptor binding site density in the hippocampus, hypothalamus and ventral striatum. Besides the
References: Hill, M. N., Carrier, E. J., McLaughlin, R. J., Morrish, A. C., Meier, S. E., Hillard, C. J., & Gorzalka, B. B. (2008). Regional alterations in the endocannabinoid system in an animal model of depression: effects of concurrent antidepressant treatment. Journal Of Neurochemistry,106(6), 2322-2336. doi:10.1111/j.1471-4159.2008.05567.x