Dose Response Study of Masculinizing Effects of Estradiol (E 2 ) Student Goals: -to see if we can replicate sex differences -to gauge the sensitivity of the female zebra finch song system to E 2 -to investigate if masculinization was an all-or-none event once a threshold was reached or show a graded response -to determine if different parts of the song system show differential sensitivity to E 2 -to determine if any of our doses of E 2 fully sex reversed the song system

Groups one group of control males (implants, no hormone) one group of control females (implants, no hormone) one group of females treated with 5 μg of E 2 one group of females treated with 15 μg of E 2 one group of females treated with 50 μg of E 2

Birds were implanted on the day they hatched and sacrificed at 100 days of age when they are fully adult.

Dependent Variables Volume of Area X Volume of HVC Volume of RA

What sort of design is this? Between or within? How many factors? –Is sex a factor? –Is estrogen treatment a factor? How many levels?

Anterior Posterior

Anterior Posterior

Anterior Posterior

Summary Lab 1 Our study will examine 4 different doses of E 2 (including zero) administered at hatching to females. A group of control males will also be included. Birds were sacrificed in adulthood at 100 days. Dependent variables are volumes of song nuclei Area X, HVC, and RA. We will use an ANOVA with post-hoc tests.