. Author manuscript; available in PMC: 2012 May 16.

Published in final edited form as: Behav Brain Res. 2010 Dec 13;219(1):15–22. doi: 10.1016/j.bbr.2010.12.003

Table 3.

Pixel Area Measurements (without mean data substitution)

Brain Region	Nest box owners	Owners Pixel Area Mean +/− SEM	Nest box Non- owners	Non-Owners Pixel Area Mean +/− SEM
VTA^*	7	9103.66 +/− 3206.408	9	28010.14 +/− 6502.517
POM^**	7	4976.16 +/− 1366.120	8	11528.34 +/− 2227.134
BSTm^**	4	4859.77 +/− 1415.464	8	16397.77 +/− 5684.518
PVN	7	18342.13 +/− 4061.620	9	19848.47 +/− 2138.746
LS	6	7429.17 +/− 1527.734	9	12099.39 +/− 2271.638
CG	7	17085.27 +/− 5289.357	9	26433.04 +/− 5474.350

indicates a significant contribution of singing behavior to mu-opioid receptor labeling density based on multiple regression analysis (p < 0.05).

^**

indicates a significant contribution of nest box ownership to mu-opioid receptor labeling density based on multiple regression analysis (p < 0.05).