Figure 1.

Recruitment of the auditory cortex, including the Te1 and Te2 cortex, in consolidating recent fearful memories to simple auditory stimuli. A, Localization of TTX injection in the Te1 (left) and Te2 (right) area. Plates are adapted from the atlas of Paxinos and Watson (1986). Te2 was defined according to the atlas of Zilles (1985). Plates were taken at the AP coordinates of 4.5 for Te1 and 6.6 for Te2 in millimeters from the bregma. The localization of injections was confirmed by Nissl staining. Representative histology of the needle track in the Te1 and Te2. Scale bar, 500 μm. Ent, Enorhinal cortex; PRh, peririnal cortex; S1, primary sensory cortex; V1, primary visual cortex; V2 secondary visual cortex. B, Experimental design of Te1 and Te2 blockade performed 1 d after CS–US pairing. C, Fear response measured as a percentage of total immobility (freezing) both at 2 min before (pre-CS) and during the overall CS presentation (CS) in saline- and TTX-injected rats and in TTX-treated rats after relearning. D, Similar results were observed by measuring overall freezing responses during CS presentation and intertrial time intervals. E, Experimental design of Te1 alone blockade performed 1 d after CS–US pairing. F, G, Te1 alone inactivation did not affect recent fear memories to the overall CS presentation (F) or to the total time spent freezing during CS presentation and intertrial intervals (G). H, Representative histology of the Te1 + Te2 excitotoxic lesions obtained though NMDA injection. Scale bars, 500 μm. I, J, Fear responses in Te1 + Te2 lesioned rats and in sham-operated animals toward CSs (I) and to the total time spent freezing during CS presentation and intertrial intervals. All values are reported as mean ± SEM.