Participation of the central noradrenergic system in the mechanisms of latent inhibition

Male Wistar rats were learnt to conditioned reaction of passive avoidance 10 days after intraperitoneal administration of 50 mg/kg of specific neurotoxin DSP4. The character of conditioned reaction reproduction, duration of its conservation and its stability against amnestic processing were analyzed. It has been found that reduction of activity of noradrenergic coerulo-cortical system does not influence the conditioned reaction reproduction but inhibits its spontaneous extinction and prevents amnesia development. The obtained data are discussed in aspect of central noradrenaline participation in latent inhibition mechanisms.