CONICET | Buscador de Institutos y Recursos Humanos

We previously described that excessive consumption of sucrose in early stages of development has deleterious neurobiological and behavioral effects in adulthood. In the present study, we evaluated whether the short-term, long-term and consolidated memory are also compromised by early sucrose consumption. 25 days after unlimited sucrose access during youth or adulthood, animals were briefly exposed to two identical objects in a 75 cm x 55 cm arena, and memory was evaluated in consecutive test trials by exchanging one of the familiar objects for a novel one. Control and sucrose-exposed rats spent the same time exploring the two objects during the sample session T1. However, when the four groups were exposed 2 h later to a copy of the objects presented in the sample session and a novel object (short-term memory, T2), control animals or animals that drank sucrose during the adulthood, but not during youth, exhibited a clear preference to explore the novel object as shown by the significant interaction between age and treatment (two-way ANOVA; F(1,28) = 4.208, P = 0.0497). Control rats and rats treated in adulthood continued to exhibit a preference to explore the novel object over the familiar one 24 h (long-term memory, T3) and 7 days after the training session (consolidated memory, T4). In contrast, rats exposed to sucrose during youth were again unable to distinguish between the novel and the familiar objects. Two-way ANOVA indicated a significant age and treatment interaction, on the capacity to discriminate the novel from the familiar object (T3; F(1,32) = 11.908, P = 0.0015 and T4; F(2,21) = 4.932, P = 0.0370). Altogether these results suggest that unlimited sucrose exposure during the child-adolescence produced long-term alterations of the hippocampus, prefrontal and perirhinal cortex and/or their connections.