Event Title

The Role of Steroid Hormones on Neuron Number and Size in the Green Anole Lizard

Location

CSU Ballroom

Start Date

20-4-2015 10:00 AM

End Date

20-4-2015 11:30 AM

Student's Major

Biological Sciences

Student's College

Science, Engineering and Technology

Mentor's Name

Rachel Cohen

Mentor's Email Address

rachel.cohen@mnsu.edu

Mentor's Department

Biological Sciences

Mentor's College

Science, Engineering and Technology

Description

Gonadal steroid hormones are important in maintaining reproductive behaviors, as well as brain morphology. Seasonally breeding animals, such as the green anole lizard (Anolis carolinensis), display dramatic seasonal changes in both brain morphology and reproductive behavior. Previous work supports the idea that anole lizards in the breeding season have an increased volume of brain regions that control reproductive behavior, such as the preoptic area (POA), and ventromedial hypothalamus (VMH). The amygdala (AMY), another region important for reproduction, has fewer neurons in breeding animals. These results suggest that steroid hormones are important in maintaining some of the breeding-like structures in the brain. In the current study, we used tissue from breeding male lizards that had been gonadectomized and treated with capsules filled with testosterone (T), dihydrotestosterone (DHT), estradiol (E2), or left empty as a control. Brain tissue was sectioned on a cryostat, mounted onto slides, and stained with Thionin. We counted neuron number and determined neuron soma size in the brain regions that control reproductive behavior (POA, AMY, and VMH). We expect to see an increase in soma size along with total cell number in brain regions that control reproductive behavior in lizards. This is most likely due to an increase in testosterone and testosterone metabolites (E2 and DHT) during the breeding period.

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Apr 20th, 10:00 AM Apr 20th, 11:30 AM

The Role of Steroid Hormones on Neuron Number and Size in the Green Anole Lizard

CSU Ballroom

Gonadal steroid hormones are important in maintaining reproductive behaviors, as well as brain morphology. Seasonally breeding animals, such as the green anole lizard (Anolis carolinensis), display dramatic seasonal changes in both brain morphology and reproductive behavior. Previous work supports the idea that anole lizards in the breeding season have an increased volume of brain regions that control reproductive behavior, such as the preoptic area (POA), and ventromedial hypothalamus (VMH). The amygdala (AMY), another region important for reproduction, has fewer neurons in breeding animals. These results suggest that steroid hormones are important in maintaining some of the breeding-like structures in the brain. In the current study, we used tissue from breeding male lizards that had been gonadectomized and treated with capsules filled with testosterone (T), dihydrotestosterone (DHT), estradiol (E2), or left empty as a control. Brain tissue was sectioned on a cryostat, mounted onto slides, and stained with Thionin. We counted neuron number and determined neuron soma size in the brain regions that control reproductive behavior (POA, AMY, and VMH). We expect to see an increase in soma size along with total cell number in brain regions that control reproductive behavior in lizards. This is most likely due to an increase in testosterone and testosterone metabolites (E2 and DHT) during the breeding period.

Recommended Citation

Booker, Nicholas and Nicholas Hart. "The Role of Steroid Hormones on Neuron Number and Size in the Green Anole Lizard." Undergraduate Research Symposium, Mankato, MN, April 20, 2015.
http://cornerstone.lib.mnsu.edu/urs/2015/poster_session_A/15