Temporal order recognition memory: behavioral characterization and ERK1/2 involvement in learning

D´HERS S; OJEA RAMOS S; GUIDOBONO JS; ROMANO A; FELD M

CABA

Congreso; XXXVII Reunion anual de la SAN; 2022

Sociedad Argentina de Investigaciones en Neurociencias

Recognition memory depends on identification and judgment of the prior occurrence ofevents. It is a very sensitive declarative memory and the use of the temporalcomponent of memory might have a relevant predictive power for early diagnosis ofAlzheimer´s disease (AD). Evidence suggests that medial prefrontal cortex (PFC) andhippocampus (HIP) are important for this memory. Here, we characterized a temporalorder recognition memory (TORM) induced by a two-session protocol in mice.Retention was assessed at 3 or 24 h in males and females. We also initiated the studyof molecular and cellular bases underlying learning of this task. Particularly, we studiedERK1/2 (extracellular-signal regulated kinase 1/2) activation, which was initiallyassociated to cell division and differentiation and was later shown to play a veryimportant role in learning and memory processes. However, its role in temporalmemories has not been elucidated yet. We found no significant differences inperformance between sexes at 2 months of age, but 3 month-old males expressed lesstotal exploration and better discrimination indexes than females in a 24 h test. Finally,although results are preliminary, we found clear tendencies in TORM-induced cytosolicERK2 activation kinetics in both structures. These promising results lead to furtherstudy the behavioral effects of local pharmacological intervention of the pathway inorder to understand its role in the formation of temporary memories.