3E–E6) suggests that these cells first migrate caudally in the

lateral subpallium before turning, and migrating in the lateral-to-medial direction within the EA. In sum, our analysis revealed that scgn+ cells cytoarchitecturally resembling migrating neurons formed a continuous stream along the palliosubpallial boundary before reaching their final destinations in the OB or EA (Fig. 4). Next, we analyzed the distribution of scgn+ neurons BKM120 molecular weight in neonatal mouse brain. We observed that the migration of scgn+ cells concluded by birth and scgn+ neurons inhabited, in an anterior-to-posterior direction, the spatially interrelated nuclei of the BST, interstitial nucleus of the posterior limb of the anterior commissure (IPAC), ventral pallidum (VP), dorsal substantia innominata (SI), and the central and medial amygdaloid nuclei (CA and MA; Fig. 5A–A7). Morphometric analysis revealed that scgn identifies divergent neuron

subpopulations with different somatic diameters in the VP and EA (Fig. 5B). By using genetically tagged reporter mice we demonstrated that scgn+ neurons either adopted a GABA phenotype along the longitudinal axis of the EA (Fig. 5D and D1), similar to scgn+/GABA+ neurons in AZD5363 datasheet the embryonic OB (Fig. 5C and C1), or co-express ChAT when found in small-diameter cholinergic neurons of the dorsal SI (Fig. 5E and E1). Collectively, our data suggest that by E18 scgn+ neurons can acquire a distribution pattern resembling that in the adult brain, and differentiate into neurochemically distinct subtypes of EA

neurons. Systematic analysis along the longitudinal axis of the fetal primate brain revealed the first contingent of scgn+ neurons in the granular and glomerular layers of the OB (Fig. 6A). However, unlike in the adult primate brain (Mulder et al., 2009b), neuroblasts migrating in the prenatal rostral migratory stream (Pencea & Luskin, 2003) did not harbour scgn expression (Fig. 6A). Pallial areas were devoid of discernible new scgn immunoreactivity. In the basal forebrain, scgn+ neurons were seen in the horizontal diagonal band, nucleus accumbens, medial septum, VP, GP and SI (Fig. 6A1–A7). In contrast to scgn distribution in the neonatal rodent brain, scgn+ cells were only infrequently found in either the CA or MA. In the hypothalamus, substantial scgn+ neuron populations occupied the paraventricular and periverticular nuclei and the supraoptic nucleus (Fig. 6A5–A7). A morphological dichotomy of scgn+ neurons was evident in the basal telencephalon (Fig. 6B): small-to-medium-sized scgn+ neurons populated the horizontal diagonal band, SI and CA. In contrast, large-diameter scgn+ neurons were found in the IPAC and GP.