Arom+→AOB neurons express ERα and are sexually dimorphic. A, ERα (cyan) was labeled through fluorescent immunohistochemistry and colocalized with a subset of arom+ neurons (red) in the MEAv with TOPRO to identify all nuclei (purple). B, 59.0 ± 2.8 % of neurons that were labeled by either ERα antibodies or tdTomato were co-labeled for both—close to the expected joint probability of approximately 63% based on independent distributions. C, More arom+ neurons are found in the male MEAv than in the female MEAv (p = 0.039; two-sample t-test). D, The average cell body was larger in the female MEAv than in the male MEAv (p = 0.0042, two-way nested ANOVA).