Table 1. Summary of gene expression specializations in budgerigar.

	NLC core	NLC shell	NLC motor	AAC core	AAC shell	AAC motor	MO core	MO shell	NAO core	NAO shell	MMSt
Baseline
PVALB	+++	++	++	+++	++	++	+++		+++		+
SLIT1				---
FOXP1	++	+
NR2A	+++	+
GLUR1	--
NADPH-d	+++	++	++	+++	++	++	+++		+++	+	++
AR	+++	+++		+++	+++		++		+++	++
mENK fiber	+++	++		+++	++	++	+++		+++	+	++
mENK cell	++	++		++
TH fiber	--	-		--	--		--	-	-		+
CGRP-LI fibers	++	++		+	+		+++		+++	+	+
Activity
DUSP1	+++	+++		+++	+++		+++	+	+++	++
C-FOS	+++	+++	+++	++	++	++	+++	+++	+++	+++	+++
EGR1	+++	+++	+++	+	+	+	+++	+++	+++	+++	+++

The data represent qualitative analyses of gene expression (mRNA or protein) labeling in the song nucleus relative to the surround of that same brain subdivision conducted in this and other studies. + = Relative level of expression higher than the surrounding non-vocal or non-motor areas;— = lower expression; no value entered means no difference relative to the surrounding areas. The other studies are: PVALB, Hara et al. [38]; SLIT1, Wang et al. [39]; FOXP1, Haesler et al. [54]; EGR-1, Feenders et al. [35]; NR2A, Wada et al. [56]; GLUR1, Wada et al. [56]; NADPH-d, Brauth et al. [57]; AR, Matsunaga and Okanoya [60]; mENK, Durand et al. [58]; TH, Roberts et al. [61]; CGRP-LI, Durand et al. [59]; DUSP1, Horita et al. [45], C-FOS, Jarvis [44]; EGR-1, Jarvis and Mello [24]. The NR2A mRNA levels are also consistent with protein levels detected by immunocytochemistry [85].