Effects of dietary n-3 fatty acid levels on gene expression of the molecular cascade of memory in mice hippocampus

SANTIAGO BIACONI; MARIA BELEN PORETTI; GIULIA MAESTRI; MARIA EMILIA SANTILLÁN; ROSARIO SOLIS; HELGI B. SCHIOTH; GRACIELA STUTZ; VALERIA PAOLA CARLINI

Córdoba

Congreso; XVII Jornadas de Investigación Científica; 2016

SECyT-FCM-UNC

Docosahexaenoic acid from the omega 3 (n-3) series is involved in neuronal growth, synaptogenesis and neurogenesis processes. Most of this substance accumulates in the nervous tissue during the perinatal period. Several studies have reported that n-3 fatty acids (FA) are able to produce changes on the behavioral expression of memory. The formation and consolidation of long term memory (LTM) rely on intracellular signals activity, gene expression and protein synthesis. In the present study we have explored the influence of different dietary levels of n-3 FA, from pregnancy to adulthood, on the gene expression of molecular mediators of the memory cascade. Three groups of albino Swiss female mice (during gestation-lactation) and then their male offspring (during weaning-adulthood) were fed with C (control, adequate in n-3 diet; 7% soya oil; n-3: 0.57%; n-6/n-3: 5.7), D (deficient in n-3 diet; 7% sunflower oil; n-3: 0%; n-6/n-3: 0) or E (excessive in n-3 diet; 7% blend oil: cod liver 60% + soya 40%; n-3: 1.25%; EPA 0.43% y DHA 0.32% n-6/n-3: 1.29). At postnatal day 63 the pups were sacrificed (12 per group) and their hippocampi were dissected to determine the gene expression of some mediators of the biochemical cascade of memory by RT-qPCR. Statistics: ANOVA and Bonferroni post hoc when appropriate. The n-3 deficiency reduces the expression of glutamate receptor NMDA isoform 1 when compared to C and E (F(32,2)=5.76; p<0.05). Moreover, the expression of cAMP response element-binding protein (CREB) was higher in E vs C (F(32,2)=4.5; p<0.05). These findings suggest that NMDA and CREB take part on the mechanism through which n-3 FA can modulate neuroplasticity and behavioral expression of memory, considering that NMDA is a membrane receptor which participates in the triggering of the memory signaling pathway and CREB is a transcription factor that regulates the acquisition and persistence of LTM in the hippocampus.