Scopolamine prevents retrogade memory interference between two different learning task

BLAKE, MG; BOCCIA, MM; KRAWCZYK, MC; BARATTI, CM

PHYSIOLOGY AND BEHAVIOR

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2011 vol. 102 p. 332 - 337

0031-9384

Subjects exposed to learning experiences could store the new information through memory consolidation process. If consolidation is interfered by exposing the experimental subjects to another novel stimulus, memory of the first learning situation is sometimes disrupted. The cholinergic system is critically involved in acquisition of new information. Here, we use low doses of the muscarinic cholinergic receptor antagonist scopolamine (SCOP) to disrupt acquisition of new information, but sparing memory consolidation of previous memories. Mice were consecutively exposed to two learning situations: the inhibitory avoidance (IA) and the nose-poke habituation (NPH) tasks. The placement of mice on a hole-board (HB), after being trained in the IA apparatus, impairs consolidation of the avoidance memory in a manner related to the duration of the exposure to the HB. If the exposure to the HB occurred after memory reactivation of the IA task, memory reconsolidation was impaired. Blockade of acquisition of the NPH task by SCOP allowed consolidation and reconsolidation of the avoidance memory. The results indicate that the exposure and perception of a novel situation are not sufficient conditions to cause impairment of retention performance about previously learned information, but effective processing leading to acquisition of the NPH task information is necessary to cause the interference between both learning situations.