Two-trial long-term memory in the crab Neohelice

ANDINA ML; ROMANO A; FELD M

Mar del Plata, Buenos Aires

Congreso; XXX Reunión anual de la Sociedad Argentina de Investigaciones en Neurociencias; 2015

Sociedad Argentina de Investigaciones en Neurociencias

The repetitive presentation of a visual danger stimulus (VDS) in contingency with a light-driven context elicits the decay in the escape response of the crab Neohelice granulata. Following the training, animals retain the low response levels 24 hs later during a test session. This long-term memory (LTM) paradigm, known as Contextual Pavlovian Conditioning (CPC), has been exhaustively studied. Recently, we developed a new device to measure the crab´s escape response that allows more detailed measurements and a thorough description of the behavior. Moreover, it allows a reduction in the number of individuals tested. Using this device, we were able to validate the previously obtained results in our lab and to reduce the number of animals needed by half. Additionally, we have made progress in studying the effect of intensity and dynamics of VDS presentation on memory retention. 24 h-LTM was observed after a 2-trial training session in spite of the different inter-trial intervals used (e.g. 3; 45 or 60 minutes). We are currently seeking experimental conditions (e.g., water absence, total time spent on device, etc.) under which 2 trials are capable of eliciting LTM, as these results disagree with previous reports. These findings open the possibility to hound deeper into the molecular mechanisms that allow memory formation under such flexible training situations.