Retrograde amnesia in praying mantis after two successive learning processes

RESUMO

Learning and memory consolidation was investigated in the mantis Stagmatoptera biocellata, by two succesive trainings a) the attak (A) avoidance training in which animals were not allowed to catch a mobile star, fallowed by the deimatic reaction (DR) avoidance training of not displaying this defensive response, or b) DR-avoidance training followed by A-avoidance training. The results showed that the presence and the 1 of A-avoidance learning and DR-avoidance learning did not affect the learning of the other training. Total retention of A-avoidance memory was demostrated when A-avoidance training was given first, whereas DR-avoidance memory was significantly lost (716%) when the DR-avoidance training was given first. The retroactive forgetting of DR-avoidance memory is considered as retrograde amnesia rather than retroactive memory inhibition because it depends on the activity during A-avoidance training (number of attacks) and not the quantity of A-avoidance learning. The magnitude of the amnesia effect due to this distracting activity in the A-avoidance training appears to be remarkably similar to that reported in a previous work using nitrogen-induced anoxia as the amnesia factor