After initial training in the radial arm maze rats were implanted with bilateral cannulae directed to the CA1 region of the rostral hippocampus. The CA1 region was selected based on previous findings demonstrating that intracerebral injections of cannabinoid agonists directed at this area disrupt memory performance in the radial arm maze (Egashira, et al 2002; Lichtman, et al 1995). Surgery was conducted under isoflurane anesthesia using a standard stereotaxic apparatus. The rat's fur on the head was shaved and cleaned with alcohol and Betadine, and ophthalmic gel was applied to each rat's eyes. An incision was made at the midline of the head with a scalpel blade to expose the skull. The coordinates for the intracerebral infusion sites from bregma (mm) were: 1) dorsal hippocampus: A/P: -3.3, L: +/-1.5, D/V: -3.0; 2) dorsal to the original target site: A/P: -3.3, L: +/-1.5, D/V: -2.0; and 3) ventral to the original target site: A/P: -3.3, L: +/-1.5, D/V: -4.0 (Paxinos and Watson 2007). Subjects were given a two week recovery period after cannulae implantation before commencing the experiments. Each intracerebral infusion
