Date of Completion

2023

Document Type

Honors College Thesis

Department

Neuroscience

Thesis Type

Honors College, College of Arts and Science Honors

First Advisor

John Green

Second Advisor

Jeremy Barry

Third Advisor

Donna Toufexis

Keywords

mTOR, ASD, PTEN, Spatial Accuracy, Neophobia, Raptor

Abstract

The Pten gene is a critical part of the mTOR pathway, encoding for cell growth. Mutation of the Pten gene in children results in enlargement of the head, epilepsy, and cognitive deficits on the Autistic Spectrum. The animal model was created to selectively knockout (KO) the gene in hippocampal granule cells and to observe their developmental growth characteristics and integration into the entorhinal cortex-hippocampal pathway. A recent study showed that this animal model also exhibited difficulties in reconciling new information and associating a familiar goal cue with novel spatial locations. We studied a genetic rescue of this phenotype through double KO (DKO) of Pten and Raptor genes in the mTOR pathway, which has been shown to rescue neuronal hypertrophy associated with Pten KO. We hypothesized that correction of Pten KO associated dendritic overgrowth in dentate gyrus granule cells will also rescue spatial cognitive deficits. However, Pten/Raptor DKO mice exhibited significantly worse performance than controls on the spatial accuracy task, most notably during the hidden cue session. One likely reason for this poorer performance is that DKO mice showed thigmotaxic behavior in the open arena in response to elimination of olfactory cues and removal of the hidden cue, suggesting neophobia. As morphological rescue was not found to rescue cognitive deficits, this strongly suggests that non-canonical mechanisms of mTOR may significantly affect entorhinal-hippocampal network activity and emotional responses to spatial novelty in the DKO model.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Available for download on Sunday, May 04, 2025

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