Thesis
Dissecting a neural circuitry from ventral hippocampus to lateral septum in the overcome of fear
Master of Science (M.S.), Drexel University
Aug 2019
DOI:
https://doi.org/10.17918/00000985
Abstract
Fear is an essential instinct for survival and everyday life; however, excessive fear such as those associated with posttraumatic stress disorder interferes with daily activities, job performance and relationships. Therefore, understanding the neural mechanism that underlies overcoming fear can provide insight into better treatment of such maladaptive fear behaviors. Multiple brain regions including the lateral septum (LS) and ventral hippocampus (vHPC) have been implicated in fear processing, however, how they interact with each other and how the overcome of fear is achieved remains unclear. Previous studies have shown that activation of the LS reduces fear responses, and, conversely, inhibition of the LS enhanced fear responses, indicating a potential role of the LS in the overcome of fear. On the other hand, the vHPC is responsible for processing spatial and contextual information, and thus is considered a pivotal site in providing fear related contextual information. Here we employed optogenetics, immunostaining techniques and a fear conditioning procedure to determine how the vHPC may communicate with the LS in the regulation of fear. We found that optogenetic activation of the vHPC-to-LS pathway robustly reduced the contextual fear responses, and interestingly, it also reduced cued fear responses. In addition, preliminary results revealed that vHPC neurons that project directly to the LS showed increased activity in the fear context. Together our results suggest that the vHPC-to-LS pathway plays an important role in regulation of conditioned fear, namely the overcome of fear, which could have clinical implications for treatment of pathological fear and anxiety disorders.
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Details
- Title
- Dissecting a neural circuitry from ventral hippocampus to lateral septum in the overcome of fear
- Creators
- Jie Jiang
- Contributors
- Dong V. Wang (Advisor)
- Awarding Institution
- Drexel University
- Degree Awarded
- Master of Science (M.S.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Number of pages
- x, 77 pages
- Resource Type
- Thesis
- Language
- English
- Academic Unit
- College of Medicine; Pharmacology and Physiology; Drexel University
- Other Identifier
- 991014695544604721