Figure 6.

The encoding but not the retrieval of associative recognition memory requires the activation of nicotinic and muscarinic cholinergic receptors in the NRe/Rh. A, Infusion of the muscarinic cholinergic receptor antagonist scopolamine. B, Infusion of the nicotinic cholinergic receptor antagonist mecamylamine into the NRe/Rh impaired performance in the object-in-place task when infusion occurred 15 min before the sample phase but not when infusion occurred 15 min before the test phase. Data are shown as mean ± SEM. n = 12. ***p < 0.001.