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. 2012 Feb 13;109(9):3504–3509. doi: 10.1073/pnas.1200742109

Fig. 3.

Fig. 3.

Endocannabinoid and norepinephrine interactions in the dorsal hippocampus on retrieval of contextual fear memory. (A) The CB receptor agonist WIN55,212–2 (WIN, 10 or 30 ng in 0.5 μL) infused into the hippocampus 1 h before the retention test impairs retrieval of contextual fear memory. Concurrent infusion of the β-adrenoceptor antagonist propranolol (1.25 μg) blocks this WIN55,212–2-induced memory retrieval impairment. Results represent mean ± SEM. *P < 0.05, **P < 0.001 vs. vehicle (n = 10–14 per group). (B) Intrahippocampal infusions of norepinephrine (1 or 3 μg in 0.5 μL) administered 1 h before the retention testing impair retrieval of contextual fear memory. Concurrent infusion of the CB1 receptor antagonist AM251 (0.35 ng) does not block this impairment. Results represent mean ± SEM. *P < 0.05, **P < 0.01 vs. vehicle (n = 11–15 per group).