The Effects of Stress on the Brain

Both the hippocampus and the prefrontal cortex react when a body becomes stressed. This reaction is then directed to the amygdala. Stress targets the amygdala as well, although its structural plasticity is different from that of the hippocampus in that it causes its neurons to grow rather than to retract as in the case of the hippocampus (Hermans, Henckens, Joëls & Fernández, 2014). Further changes occur in the way neurons are excited; this is controlled by repeated stress and adrenal steroids. Many sensory inputs converge in the amygdala, which makes up brain components that aid in decoding sensations (feelings) that pose threats to organisms. The information is availed directly to the amygdala from a number of sensory cortexes and sensory thalamus. However, other regions like the hypothalamus, reticular of the brainstem, and septum also have their axons on the amygdala (Duman, Aghajanian, Sanacora & Krystal, 2016).

This zone receives several connections to the hippocampus since it’s attributed to storing and retrieving overt memories. In addition to that, the prefrontal cortex forms connection to the amygdala. These connections help in the extinction process in which the external stimulus sends information to the amygdale a number of ways. This essay aims at discussing the various parts of the brain and how they are affected by stress (Melanie, 2012). Glucocorticoids have a number of effects which includes damage of the brain neurons. The damage caused further leads to stress or rather trauma to an individual (Hermans et al., 2014). Consequently, this stress or traumatic experiences causes the hippocampus, which is responsible for the building of new and time-sequenced memories. On the hand, the prefrontal cortex is destroyed by too much stress. This affects to a great extent its functioning, which includes regulation ad control of impulse, processing of emotions, problem-solving, and adaptation to the challenges (Melanie, 2012).

According to the recent studies, Duman et al. (2016) suggested that Hippocampus is a vulnerable region of the brain affected by the stress hormones. Furthermore, the damage on the normal plasticity caused by head trauma, seizures, and ischemia are exhibited by the excitatory amino acids. Due to these changes, the hippocampal-dependent memory functions decrease while the amygdala related aggression and fear increase. Additionally, the prefrontal cortex is highly targeted by the chronic stress that later shows numerous dendrites. The hippocampus concentrates on dispensing array of stimuli or rather context of a certain situation. These has effects on the amygdala studies in that the decoding of emotions threatening to the organism is perfectly done and hence grouping many of our bodies’ alarm circuits (Neville, Stevens, Pakulak, Bell, Fanning, Klein & Isbell, 2013).

When the structures of these particular regions change, they swiftly adjust to the current condition to allow them help the brain to cope up with the arising problem. Neurogenesis is the production of neurons from the neural stem cells and progenitor cells. The process occurs in the sub-granular zone of dentate gyrus found in the hippocampus and sub-ventricular zone of lateral ventricles (Hermans et al., 2014). The regeneration of the Hippocampal cells regulates neurogenesis, which affects its growth. The process follows a defined mechanism, this occurs when amygdala relays a signal, which alerts the organism of the presence of the threat. The cortisol hormone released momentarily enables the organism to fend off from the attacking event (The Brain from Top to Bottom, n.d.).

Conclusion

Considering the action of cortisol hormone, the hippocampal volume rather decreases in relation to PTSD. This leads to hypothalamic-pituitary-adrenal and release of cortisol hormones activation. It’s the presence of the hormone that suppresses the functioning of the hippocampus in the activation pathways and consequently resulting in depression. There are several methods which can be used to counteract chronic stress (Melanie, 2012). First is taking a daily Docosahexaenoic acid (DHA) supplement which makes the work effectively (Neville et al., 2013). Moreover, exercising often strengthens the brain cells and neuronal connections.

References

Hermans, E.J., Henckens, M.J., Joëls, M., & Fernández, G. (2014). Dynamic adaptation of large-scale brain networks in response to acute stressors. Trends in neurosciences, 37(6), 304-314.

Neville, H.J., Stevens, C., Pakulak, E., Bell, T.A., Fanning, J., Klein, S., & Isbell, E. (2013). Family-based training program improves brain function, cognition, and behavior in lower socioeconomic status preschoolers. Proceedings of the National Academy of Sciences, 110(29), 12138-12143.

Duman, R. S., Aghajanian, G. K., Sanacora, G., & Krystal, J. H. (2016). Synaptic plasticity and depression: new insights from stress and rapid-acting antidepressants. Nature medicine, 22(3), 238.

Melanie. G. (2012). How to Prevent Stress from Shrinking your Brain. Retrieved from https://www.psychologytoday.com/blog/the-mindful-self-express/201208/how-prevent-stress-shrinking-your-brain The Brain from Top to Bottom. (n.d.). The Amygdala and Its Allies. Retrieved from: http://thebrain.mcgill.ca/flash/d/d_04/d_04_cr/d_04_cr_peu/d_04_cr_peu.html