Figure 2.

Repeated cannabinoid treatment during adulthood alters CB₁ immunostaining primarily within vocal-motor-related regions of zebra finch brain (HVC, RA, and DLM). Initial daily treatments over 25 days are indicated by first designations (VEH-, WIN-). Later, single acute treatments are indicated second (-VEH, -WIN, see Table 1). Basal staining levels are increased following repeated WIN exposure in adulthood in (B) HVC, (D) RA, and (F) DLM (compare VEH-VEH to WIN-VEH in these panels). Acute responsiveness is not modified following repeated treatments (compare VEH-WIN and WIN-WIN). Chronic treatment did increase responsiveness within the molecular layer of the cerebellum (double-dagger, panel G) Asterisks indicate differences from VEH-VEH treatment groups (p < 0.05, one-way ANOVA followed by SNK post-tests).