Figure 4.

Topographic distribution of GFP immunofluorescence in the NAc of Drd3-Cre mice crossed with the Rosa26:loxP reporter line. (A) Single confocal sections were stitched together as a single image. Scale bar: 500 μm. DStr, dorsal striatum; aca, anterior commissure; ICjM, islands of Calleja major; Tu, olfactory tubercles. Note that GFP-positive cells are restricted to the caudomedial part of the NAc shell. Only sparse GFP-expressing cells were detected in the NAc core. (B) Schematic illustration of the accumbal subterritories analyzed (see Figure A1). Cyan in the diagram represents the distribution of GFP-expressing cells. A zone homogenously cyan means the GFP is homogenously distributed. White means lack of GFP expression throughout the zone and dots indicate that few GFP cells are detected throughout the zone. Single scan confocal images showing double stained for GFP (cyan) and DARPP-32 (red) in the dorsal caudomedial (GFP, B₁; DARPP-32, B₂; merge, B₃) and ventral (GFP, B₄; DARPP-32, B₅; merge, B₆) part of the shell of Drd3-Cre mice. Images shown are representative of all Drd3-Cre BAC transgenic mice analyzed (n = 2). Yellow asterisk identifies the D2R-expressing MSNs-poor zone. Yellow arrowheads identify the bundle-shaped area. Scale bar: 200 μm.