Cognition, Behavior, and Memory
Author: luciano cavallino | email: lcavallino@hotmail.com
Luciano Cavallino 1°, Maria Florencia Scaia 1°, Andrea Pozzi 1°, Maria Eugenia Pedreira 2°
1° Laboratorio de Neuroendocrinología y comportamiento en peces y anfibios, DBBE, IBBEA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CABA, Argentina
2° Laboratorio de Neurobiología de la Memoria, FBMC, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CABA, Argentina.
Aggressive encounters can cause injuries and require a significant energy investment. Recognizing and remembering a previous opponent can be beneficial since it can facilitate changes in fighting strategies. We demonstrate that, zebrafish males resolve a second encounter against the same opponent with lower levels of aggression, implying a recognition encounter memory. To analyze the memory consolidation, pairs of adult zebrafish males were allowed to participate in an agonistic encounter. After 30 minutes, individuals were separated and immediately exposed to 15 or 60 minutes of water or MK-801 (antagonist of NMDA receptor, 20 ?M). Same pairs were isolated again for 24 or 48 hours and exposed to a second fight against the same opponent. Total time of aggression and number of bites were compared between day 1 and 2. Results suggest that individuals exposed to water and to 15 min MK-801resolve the second encounter with significantly lower levels of aggression. Nevertheless, after 60 minute exposure to MK-801, no differences were found in aggression between day 1 and 2, regardless of the interval between fights (24 or 48 hours). These results suggest that individuals resolve subsequent encounters against the same opponent with lower aggression, but 60 minutes of drug treatment after the first encounter restores, at the second encounter, the levels of aggression of the first day. The results suggest that blocking NMDA receptors impairs the encounter-memory consolidation.