Figure 6.

A history of self-administering slow cocaine injections (delivered over 90 vs 5 s) leads to a greater increase in agonist-stimulated [³⁵S]GTPγS binding in the caudate-putamen. Quinpirole-stimulated [³⁵S]GTPγS activity in the dorsomedial (a), dorsolateral (b), ventromedial (c), and ventrolateral (d) quadrants of the caudate-putamen, as well as in the nucleus accumbens core (e) and shell (f) 14 days after the last self-administration session in animals that had self-administered cocaine delivered over 5 or 90 s and in control rats. In panel (e), the inset shows data at +0.8 mm relative to Bregma. C, nucleus accumbens core; S, nucleus accumbens shell. Data represent mean±SEM. n=6–7/group. *P<0.05 relative to the 5-s group at corresponding rostro-caudal position. ^#P<0.05 relative to the control group at corresponding rostro-caudal position.