Figure 3.

Intra-LA infusion of a PKG activator enhances ERK phosphorylation in the LA and MGm/PIN following fear conditioning. (A) Schematic of behavioral protocol. Rats were given intra-LA infusion of the vehicle (n =6) or 8-Br-cGMP (10 µg/side; n =8), followed 1 h later by fear conditioning. Rats were sacrificed 1 h following training. (B) Representative blots for both phospho-ERK (pERK) and total ERK in the LA. (C) Representative blots for both pERK and total ERK in the MGm/PIN. (D) Mean (± SEM) percent pERK immunoreactivity from LA punches taken from rats given intra-LA infusions of vehicle or 8-Br-cGMP. Here, pERK levels have been normalized to total ERK levels for each sample. (E) Mean (± SEM) percent total-ERK immunoreactivity from LA punches taken from rats given intra-LA infusions of vehicle or 8-Br-cGMP. Here, total ERK levels have been normalized to GAPDH levels for each sample. (F) Mean (± SEM) percent pERK immunoreactivity from MGm/PIN punches taken from the rats in D given intra-LA infusions of vehicle or 8-Br-cGMP. Here, pERK levels have been normalized to total ERK levels for each sample. (G) Mean (± SEM) percent total-ERK immunoreactivity from MGm/PIN punches taken from the rats in D given intra-LA infusions of vehicle or 8-Br-cGMP. Here, total ERK levels have been normalized to GAPDH levels for each sample. (H) Representative 10X photomicrograph of the LA of an animal given intra-LA infusion of vehicle, trained, and sacrificed 1 h later. (I) Representative 10X photomicrograph of the LA of an animal given intra-LA infusion of 8-Br-cGMP (10 µg/side), trained, and sacrificed 1 h later. (J) Representative 10X photomicrograph of the MGm/PIN of an animal given intra-LA infusion of vehicle, trained, and sacrificed 1 h later. (K) Representative 10X photomicrograph of the MGm/PIN of an animal given intra-LA infusion of 8-Br cGMP (10 µg/side), trained, and sacrificed 1 h later. (*) P< 0.05 relative to vehicle-infused rats.