Theses and Dissertations

Issuing Body

Mississippi State University


Krishnan, Natraj

Committee Member

Harris, Jeffrey W.

Committee Member

Goddard, Jerome

Committee Member

Farnell, Yuhua

Date of Degree


Document Type

Graduate Thesis - Open Access



Degree Name

Master of Science (M.S.)


College of Agriculture and Life Sciences


Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology


Dopamine (DA) is a catecholamine that is involved in several neural functions such as modulation of locomotor behaviors, arousal states to appetitive aversive learning and memory. The relationships between DA, stress response and aging are unclear. This thesis examines numerous physiological, behavioral and biochemical parameters following perturbations in DA synthesis and transport in the Drosophila melanogaster model system. Intriguingly, elevated DA pools appear to confer protection, while depleted DA levels or transport increase susceptibility to oxidative insult. Resistance to oxidative stress in mutants with elevated DA levels was attributed to a significant up-regulation of glutathione S-transferase Omega-1. A sexually dimorphic response in aging and senescence characteristics was also recorded among the mutants tested, but no discernable role of DA in these characteristics was observed. Taken together, these results point to a key role played by DA in stress response, which might have implications to age-related neurodegenerative diseases.