Neural Mechanisms of Juvenile Aggression
Abstract/Contents
- Abstract
- Aggression in juveniles is an evolutionarily adaptive behavior documented in many species, but the neural mechanisms behind these displays are poorly understood. In humans, the importance of knowing what is happening in the brain during maladaptive aggression is especially key in instances of psychiatric disorders that display as aggressive tendencies in childhood, such as autism spectrum disorders (ASD), schizophrenia, and borderline personality disorder. Mimetic poison frog (Ranitomeya imitator) tadpoles live in small pools with limited resources and have evolved offensive aggressive tendencies towards conspecific tadpoles in defense of these resources. Tadpoles will attack, kill, and cannibalize other tadpoles as a primary resource defense mechanism. I examined the neural basis of neonate aggression in these tadpoles by comparing individuals that were placed in aggressive encounters and individuals placed in an environment with a non-threatening stimulus. I first did a longitudinal study to determine that the tadpoles were most aggressive when they were around five or six weeks old. I then compared patterns of generalized neural activity using immunohistochemical detection of phosphorylated ribosomes and a candidate neuropeptide, arginine vasotocin, which has been implicated in aggression in other vertebrates. Vasotocin cells in the preoptic area of the hypothalamus were not more active in aggressive tadpoles. I then examined neural activation across several brain regions suspected to be involved in aggression, and found that the anterior amygdala had the most neural activation in aggressive tadpoles compared to controls and the other brain regions. Through molecularly profiling active neurons using phosphoTRAP, I identified proopiomelanocortin (POMC), a precursor polypeptide with multiple post-translational peptides, as enriched in active neurons during aggression. Through pharmacological manipulations with the peptides of POMC (aMSH, ACTH, and B-endorphin), I found that a B-endorphin antagonist significantly increased aggressive behavior in tadpoles. Overall, this project is advancing understanding of how aggression is regulated in the juvenile brain.
Description
| Type of resource | text |
|---|---|
| Date modified | December 5, 2022 |
| Publication date | May 6, 2022; May 2022 |
Creators/Contributors
| Author | McKinney, Jordan |
|---|---|
| Thesis advisor | O'Connell, Lauren |
| Thesis advisor | Luo, Liqun |
| Researcher | Ludington, Sarah |
| Editor | Butler, Julie |
| Degree granting institution | Stanford University, Department of Biology |
Subjects
| Subject | violence, development, neuroethology, POMC, B-endorphins |
|---|---|
| Genre | Text |
| Genre | Thesis |
Bibliographic information
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- User agrees that, where applicable, content will not be used to identify or to otherwise infringe the privacy or confidentiality rights of individuals. Content distributed via the Stanford Digital Repository may be subject to additional license and use restrictions applied by the depositor.
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 4.0 International license (CC BY-NC).
Preferred citation
- Preferred citation
- McKinney, J. and O'Connell, L. (2022). Neural Mechanisms of Juvenile Aggression. Stanford Digital Repository. Available at https://purl.stanford.edu/dc783sw6928
Collection
Undergraduate Theses, Department of Biology, 2021-2022
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