Fornix transection: discrimination between neuropeptide effects on attention and memory

Transection of the fornix and the stria terminalis completely blocks the inhibitory action of ACTH 4-10 on extinction of a conditioned avoidance response (CAR), whereas this effect of the vasopressin analogue des-glycinamide-lysine-vasopressin (DG-LVP) is not affected. These data indicate that the behavioral effect of DG-LVP may be localized to certain anatomical substrates, while ACTH 4-10 needs an intact limbic system as a functional substrate for its effect on avoidance behavior. This differential effect of fornicotomy may also be interpreted as a discrimination between the effects of these neuropeptides on attention or on memory consolidation. Additionally, transection of the fornix and the stria terminalis induces an increase in motor responsiveness to an electric footshock (EFS) and a facilitation of acquisition of a CAR.