Detection of PHA-L and CTb in the BNST after injection in the prefrontal cortex and mesencephalon (diagram in A). B, Injection sites. Left, The anterograde tracer PHA-L was injected in the infralimbic cortex (ILCx): bregma + 3.0 mm; 0.5 mm from medial line and 4.5 mm from surface. Right, The retrograde tracer CTb was restricted to the VTA: bregma, −5.3 mm; 0.8 mm from medial line and 8.2 mm from surface. Scale bar, 100 μm. C, Immunofluorescence confocal image showing the ILCx projection to the BNST. C′, Note how some PHA-L positive axons (arrowhead) reach the neuropile and cell bodies of CTb-positive neurons (arrow). Scale bars: C, 100 μm; C′, 20 μm.