Department or Program

Neuroscience

Abstract

The accessory olfactory bulb (AOB) is a sensory brain region critical for detecting and discriminating between socially relevant chemical signals from conspecifics. Additionally, the AOB is a well-established locus of social memory, with long-lasting, well-localized, and stimulus-specific physiological changes capable of decreasing AOB output upon reactivation by a specific odor. I investigated whether such plastic changes in the AOB are selectively induced by the odors of dominant, but not subordinate individuals, to characterize a hypothesized, but unidentified memory for signals conveying social rank. I established social hierarchies in male mice using the tube test to identify dominant and subordinate individuals. Female mice were reared for nine days on bedding from the cages of dominant or subordinate males. Following rearing, in vitro whole-cell recordings from female AOB slices were used to determine how dominant vs. subordinate male odors alter intrinsic and synaptic properties of AOB principal neurons (mitral cells). I found that exposure to both dominant and subordinate male odors is sufficient to induce long-term changes in synaptic properties, namely recurrent inhibition. Additionally, dominant odor exposure tended to decrease neuronal excitability while subordinate odors increased excitability. Together, these results indicate that pre-exposure to dominant male pheromones tends to diminish mitral cell firing, which is known to constitute a particular form of memory, while subordinate pheromones may increase the responsiveness of mitral cells, suggesting that the AOB may selectively prioritize odors from dominant individuals.

Level of Access

Restricted: Archival Copy [No Access]

First Advisor

Castro, Jason

Date of Graduation

5-2013

Degree Name

Bachelor of Science

Number of Pages

72

Components of Thesis

1 pdf file

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