Date of Award


Degree Type


Degree Name

Master of Science


Psychological Science


Psychological Science (MS)

First Advisor/Chairperson

Dr. Adam Prus


Systemic administration of the NTS1 receptor agonist PD149163 has exhibited anxiolytic effects in male rats. The present study sought to further evaluate the potential anxiolytic effects of PD149163 by assessing this compound in both male and female C57BL/J6 mice using the fear-potentiated startle (FPS) paradigm. Startle chambers were equipped with a shock-grid floor, fluorescent light, and an acoustic startle speaker. Conditioning took place between the light and floor shock, and test sessions measured startle to a 90 dB noise burst while the light was on (FPS) or off. Startle magnitude did not differ between the male and female mice. PD149163 produced a significant difference between male and female mice startle response and a significant reduction in FPS in females. The NTS2 receptor agonist β-Lactotensin produced a sex difference at an intermediate dose. The anxiolytic and partial 5-HT1A agonist buspirone did not produce a significant difference in FPS. The reduction in FPS by PD149163 coincides with previous studies conducted in male rats. The reduction in FPS found in female mice suggests that more research is needed to examine the neurotensin system and sex differences. Overall, these findings support targeting the neurotensin system for the development of novel strategies for treating anxiety disorders.

Access Type

Open Access