Figure 4.
a) Plasma dehydroepiandrosterone (DHEA) levels in wild adult male song sparrows in the non-breeding season (autumn and winter). Plasma levels of DHEA were significantly higher than plasma testosterone (T) and estradiol (E2) levels. Plasma concentrations of T and E2 were non-detectable (< 0.1 ng/ml). From Soma et al. (2001); b) Effect of DHEA treatment on adult song system neuroanatomy. Compared to controls (CON), DHEA treatment significantly increases the volume of HVC. Overall telencephalon volume is not affected by DHEA treatment **p<0.01. (from Soma et al., 2002).