Steroid Hormone Effect on Neurons of the Amygdala and the Preoptic Area in the Brain of Green Anole Lizards

Presenter Information

Mohamed Alhuwaish, Minnesota State University, Mankato
Georgia Meulken, Minnesota State University, Mankato
Spencer Savannah, Minnesota State University, Mankato

Location

CSU Ballroom

Start Date

2-4-2019 10:00 AM

End Date

2-4-2019 11:30 AM

Student's Major

Biological Sciences

Student's College

Science, Engineering and Technology

Mentor's Name

Rachel Cohen

Mentor's Department

Biological Sciences

Mentor's College

Science, Engineering and Technology

Description

Testosterone has distinct effects on seasonal brain morphology and behavior. The seasonally breeding green anole lizard, Anolis carolinensis, has distinct behaviors during the breeding season, such as reproductive displays and territorial behaviors. Interestingly, these behaviors are not observed during the non-breeding season. We are examining two forebrain areas, the preoptic area (POA) which facilitates masculine reproductive behavior under androgen treatment, and the amygdala (AMY) which plays a role in fear behaviors. These areas are also known to change volume seasonally, but the specific mechanism is unknown. Our experiment seeks to understand the mechanism by which steroid hormones act on nuclei in the forebrain to induce seasonal differences using gonadectomized breeding season males. Each individual was treated with testosterone, dihydrotestosterone, estradiol, or vehicle. We expect to see soma size and cell numbers in steroid hormone treated lizards to be restored to breeding season levels within the POA and the AMY, as has been shown in previous work. Overall, our experiment suggests that steroid hormones can impact brain morphology. Future studies may investigate different factors that may contribute to the increase in POA or AMY volumes in the breeding season like glial cell count or measuring the distances between neurons.