ORCID

https://orcid.org/0009-0004-2136-4839

Date of Award

2026

Document Type

Thesis

Degree Name

MS in Neuroscience

Department

Biological Sciences

First Advisor

Robert R Kozol

Second Advisor

Javier Juarez

Third Advisor

Roberto Rodriguez

Abstract

Kinematic analysis pipelines now provide temporal and geometric resolution for determining a variety of body movement. These machine-learning trained programs allow behavioral neuroscientists to dissect complex behaviors and relate changes in those movements to conserved neural assemblages. These analyses are common in model organisms, but a lack of ethologically driven kinematic work in non-models has hampered our understanding of how evolution shapes behavior through sensorimotor circuits. Astyanax Mexicanus is a unique model organism that allows us to understand how evolutionary divergence as a result of adaptation to environmental conditions leads to genotypic and associated phenotypic changes in brain development and behavior. In this study, we analyzed the kinematic movements in open-arena assays of 1 to 2 week old larvae of wildtype and hybrid genotypes of surface and cave fish populations (Molino, Tinaja, Pachon) (n=40 for each population) (n=80). 10-15 second videos of open arena conditions were recorded at 200 fps, specifically aimed to identify behavioral differences in white light and infrared light conditions. Bout transition probabilities were analyzed using spectral gap and spectral entropy metrics. Analysis of bout transition probabilities in cave and surface populations reveals that all populations exhibit a conserved dominant exploratory scaffold, but differ in how they allocate probability mass across subsidiary motor programs. Baseline flexibility across all conditions for surface fish is generally higher while cavefish depict more stereotypy in behaviors. In general, transition from IR to white light resulted in increased mixing of behavioral states. These results suggest that central sensorimotor architectures are preserved, with the process of evolution exerts change upon bout dynamics through genetic variation and environmental variability.

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