Skip to main content
. 2006 Jun 14;26(24):6458–6468. doi: 10.1523/JNEUROSCI.0707-06.2006

Figure 3.

Figure 3.

Activation or blockade of CB1 receptors with WIN 55,212-2 (0.05–0.5 mg/kg, i.v.) or AM-251 (0.1–1.0 mg/kg, i.v.) modulates emotional learning in BLA-responsive neurons of the mPFC. A, After a subthreshold dose of WIN 55,212-2 (0.05 mg/kg), mPFC neurons display associative responding to the CS+ at a similar magnitude to saline controls. A higher dose (0.5 mg/kg) causes a potentiation in the neuronal associative response to the CS+ presentation. Pharmacological inactivation of the BLA with muscimol (500 ng) before olfactory conditioning but after WIN 55,212-2 (0.5 mg/kg) administration prevents neuronal associative responding at testing. However, if the BLA is inactivated after conditioning in animals given WIN 55,212-2 (0.5 mg/kg) before conditioning, BLA-responsive mPFC neurons still display robust potentiation of associative responding to the CS+ presentation relative to saline control animals. Pre-Cond, Preconditioning; Post-Cond, postconditioning. B, Comparing preconditioning and postconditioning 10 s odor presentations demonstrates that CB1 receptor activation with WIN 55,212-2 (0.5 mg/kg) potentiates associative neuronal responding specifically to CS+ presentations relative to saline control or animals pretreated with a lower dose of WIN 55,212-2 (0.05 mg/kg). C, Blockade of CB1 receptors with a competitive CB1 receptor antagonist, AM-251, blocked neuronal associative learning in BLA-responsive neurons of the mPFC at an intravenous dose of 1.0 mg/kg. A lower dose (0.1 mg/kg, i.v.) had no effect on associative neuronal responding relative to saline control animals. Pretreatment with AM-251 (1.0 mg/kg, i.v.) blocks the associative learning potentiation induced by WIN 55,212-2 (0.5 mg/kg, i.v.). D, Comparing preconditioning and postconditioning 10 s odor presentations after AM-251 pretreatment (0.1 or 1.0 mg/kg, i.v.) demonstrates that CB1 receptor blockade at the higher dose (1.0 mg/kg) prevents neuronal associative responding in response to CS+ presentations. E, Neither administration of the CB1 antagonist AM-251 (0.1 and 1.0 mg/kg, i.v.) nor the CB1 receptor agonist WIN 55,212-2 (0.05–0.5 mg/kg, i.v.) caused any significant alterations in spontaneous neuronal activity after injection. Pre, Preconditioning; Post, postconditioning. Error bars indicate mean ± SEM.