Neural stem cells in
the subventricular zone (SVZ) generate progenitors which in turn give rise to neuroblasts. These neuroblasts
then migrate along
the rostral migratory stream (RMS) in chains and reach
the olfactory bulb (OB), where
they mature into local interneurons. Interneurons in
the OB are heterogeneous, which are mainly located in
granular cell
layer (GCL), external plexiform
layer (EPL) and glomerular
layer (GL). In this study, we show that green fluorescent protein-expressing (GFP+) cells in
the SVZ and RMS
of the 5HT3aR-BAC
EGFP transgenic mouse exclusively express transcription factor
Sp8 which is expressed in lateral ganglionic embryonic eminence (LGE) and postnatal SVZ.
These GFP+ neuroblasts of the 5HT3aR-BACEGFP transgenic mouse migrate along the RMS to the OB where they differentiate into calretinin+ (CR+), parvabumin+ (PV+), vasoactive intestinal peptide+ (VIP+), somatostatin+ (Som+) and tyrosine hydroxylase+ (TH+), but not calbindin+ (CB+) interneurons. These GFP+ interneurons continuously express Sp8 in the OB. Furthermore, these results suggest that GFP-expressing cells are derived from LGE, and this transgenic mouse line will be a useful tool for studying the development and function of interneurons in both neocortex and OB.