Figure 3.
VNS enhances extinction of remote conditioned fear. Percent of conditioned freezing in sham and VNS-treated rats given delayed extinction training. Extinction trials began 2 weeks after fear conditioning. VNS or sham stimulation overlapped with the conditioned tone on treatment trials. Test trials were given on alternate days. Although both groups demonstrated remission of fear responding, VNS-treated rats reached the remission point more rapidly than sham-treated rats, indicating that remote memory is not resistant to VNS enhancement of extinction (p<.05).