Effect of chronic administration of WIN 55,212-2 on medial prefrontal cortex (mPFC) pyramidal neuronal morphology. Chronic administration of WIN 55,212-2 (3.0 mg/kg, 14 days) increased dendritic length of mPFC neurons in adult rats. Spine density was not affected by WIN 55,212-2 treatment, but was affected by age where adult rats present higher density of spines near the soma, *p < 0.05