Figure 3.

Photomicrographs of PCREB immunostaining in the caudoputamen (A–C) and in the olfactory tubercle (A′–C′) of slice cultures treated for 8 hr with the dopamine D1-class receptor agonist (A and A′), forskolin (B and B′), or the L-type Ca²⁺ channel agonist, BAY K 8644 (C and C′). Eight hours after SKF-81297 stimulation of D1-class dopamine receptors, PCREB immunoreactivity is reduced to background levels in the caudoputamen (A), but persistent, weak PCREB immunostaining remains in the islands of the olfactory tubercle (curved arrow in A′). With 8-hr forskolin treatment, only weak PCREB immunoreactivity is found in the caudoputamen (B), but moderate levels of PCREB immunostaining are still present in the olfactory tubercle islands (curved arrow in B′). Only background levels of PCREB immunoreactivity are present in the caudoputamen (C) and olfactory tubercle (C′) 8 hr after BAY K 8644 stimulation. The arrowheads in A′–C′ mark the ventral edges of the tissue. fb, fiber bundles. [Bar in C (for A–C) = 100 μm; bar in B′ (for A′–C′) = 0.5 mm.]