Researcher(s)
- Aryan Mehta, Neuroscience, University of Delaware
Faculty Mentor(s)
- Dayan Knox, Psychological and Brain Sciences, University of Delaware
Abstract
The Stress Circuit(s) in the brain is among one of the most studied circuits and among one of the most coveted circuits to understand to advance treatments in Anxiety, PTSD, and Chronic Stress. The dangers of stress are not only psychologically relevant, but physiologically, as these stress disorders are often associated with Depression, Weight Mismanagement, Cardiovascular Disease, and more. One of the regions in the brain that is highly active in contextualizing stimuli relative to the stress they produce is the Ventral Hippocampus (vHPC), a subregion of the part of the brain heavily involved in memory formation and recollection. The VHPC renders us capable of avoiding fear generalization, or in other words, not being scared of 1 stimulus in every single context. Changes in brain size are often a key marker of strengthening/weakening of a circuit or a behavior. Previous studies have discovered that exposure to Single Prolonged Stress, an Animal Stress model which induces PTSD-like Symptoms, can prevent expansion of the Hippocampus; interestingly, artificially inhibiting the VHPC can have the same effect. But, what of the other areas that the vHPC projects to, such as the Prelimbic Cortex, and the Amygdala. This research targets the inhibition of the VHPC in Rats and exposing the rats, along with a group of control rats, to a stress protocol involving Fear Extinction. The research focuses on analyzing the changes in Brain Volumes in these certain brain regions that the VHPC forms connections with in order to discern how VHPC inhibition physiologically affects the size of these related brain regions. Research revealed that inhibition of the vHPC did not produce significantly decreased changes in anatomical volumes in the Prelimbic Cortex, Basolateral Amygdala, and Central Amygdala, but there was a significant difference in the change in the Medial Amygdala’s volume.