FIGURE 8. Blockade of Fos induction by SCH-23390. (A) Diagram of 
forebrain section illustrating region of caudate shown in B through 
F. (B) Saline-treated control. (C) 2 hours after cocaine 30 mg/kg 
IP. (D through F) High-power micrographs of caudate from rats 
2 hours after treatment with cocaine 30 mg/kg IP alone (D), or 
pretreated 30 minutes prior to cocaine with the D1 antagonist 
SCH-23390 at 10 pg/kg (E) and 50 pg/kg (F). The bar in all cases 
equals 100 pm; v-lateral ventricle. Preadsorption of the antibody 
with the antigenic peptide abolished all staining (not shown). 
SOURCE: Young etal. 1991 
cocaine, but there was not a clear dose-related inhibition of the cocaine-induced 
elevation of Fos-immunoreactive nuclei (figure 9, lower panel). Administration 
of the antagonists alone produced no significant effect on the number of Fos- 
immunoreactive cell nuclei. These data suggest that the main receptor 
mediating the induction of c -fos in striatal neurons is the D1 receptor. Since 
the D1 receptor is positively linked to adenylate cyclase, it suggests the cyclic 
193 
