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Date of Award
5-2025
Document Type
Restricted Thesis: Campus only access
Degree Name
Bachelor of Arts
Department
Psychology
First Advisor
Dr. Kelly Lambert
Abstract
Although an animal's environment significantly impacts the brain, minimally stimulating environments are often used in laboratory investigations of neurobiology. Our lab is interested in behavioral and neural differences between wild-trapped and laboratory-bred rats to emphasize the importance of ecological relevant environments in preclinical research. Previously, we reported that wild rats exhibit increased stress reactivity as well as higher neuronal densities in the cerebellum compared to laboratory rats (Jacob et al., 2022). Given the physical and emotional demands of rats in the wild versus the laboratory, the present study investigated neurobiological differences in brain regions implicated in movement and defensive behavior in wild and laboratory rats. To investigate this, Nissl staining was used to quantify neural versus glial cells in the motor cortex (MC) and the zona incerta (ZI; a subthalamic structure implicated in the integration of motor, sensory and emotional responses (Ricci et al., 2024) in urban-wild and laboratory rats. Further, the morphology of neurons in the motor cortex (MC) was quantified using Golgi-cox stained tissue. Immunofluorescence was also used to visualize and quantify dopaminergic cells in the ZI of rural-wild and laboratory rats. Results indicated a nonsignificant trend for habitat in apical dendrite length (N = 6, p = 0.097), with the wild rats exhibiting longer dendritic length than the laboratory rats. In the ZI, nonsignificant trends also suggested higher neuron counts in the wild rats (N = 6, p = 0.062), and higher densities of dopamine-immunoreactive tissue (N = 8, p = 0.078) when compared to laboratory rats. There was also a main effect of sex in the ZI projection data, indicating that male rats have significantly higher ZI projections than female rats (N = 8, p = 0.042). Together, these findings highlight the impact of habitat on brain areas critical for sensorimotor integration in rats, offering insights into mechanisms of environmental adaptation in rodents.
Recommended Citation
DiLandro, Isabel, "The Cage Versus the Canopy: How Environment Shapes Neuromotor Mechanisms in Male and Female Rattus norvegicus" (2025). Honors Theses. 1810.
https://scholarship.richmond.edu/honors-theses/1810
