Handling altered cannabinoid receptor densities within the limbic input-output loop of the basal ganglia (see Fig. 4–5). Handled rats exhibited increased cannabinoid receptor densities in the lateral globus pallidus (Handling main effect: F1,23 = 6.57, P = 0.017; η2 = 0.197; Fig. 7a), cingulate cortex (Handling main effect: F1,23 = 10.06, P = 0.004; η2 = 0.272; Fig. 7b), and piriform cortex (Handling main effect: F1,23 = 4.79, P = 0.039; η2 = 0.165; Fig. 7c) relative to non-handled rats. By contrast, handling decreased cannabinoid receptor densities in CA1–3 and the dentate gyrus of the hippocampus compared to non-handling (Handling main effect: F1,24 = 4.38, P = 0.047; η2 = 0.143; Fig. 7d). Subsequent analysis revealed that handled rats exhibited decreased cannabinoid receptor densities in CA2 (Handling main effect: F1,24 = 5.95, P = 0.022; η2 = 0.183; Data not shown) and, to a lesser extent, in CA1–3 (Handling main effect: F1,24 = 4.10, P = 0.054; η2 = 0.136; Data not shown), compared to non-handled rats.
