Conférence Guillaume Ferreira - Adolescent obesogenic diet impairs memory through hippocampal overactivation

The obesity pandemic is linked to cognitive disorders in humans. Growing prevalence of obesity during adolescence is particularly alarming since it is a critical period for maturation of brain structures, such as the hippocampus, required for shaping memory functions for the whole life duration.

Using rodent models, we showed seminal evidence that obesogenic high-fat diet (HFD) intake during adolescence has more detrimental impact on hippocampal memory functions and plasticity than HFD intake at adulthood. Recently we found surprising results indicating that HFD-induced memory deficits are associated with enhanced hippocampal neuronal activity. Interestingly, normalization of hippocampal aberrant activity, through chemogenetic silencing of glutamatergic principal neurons or efferent pathways to ventral striatum or prefrontal cortex, is able to rescue memory deficits in adolescent HFD-fed rodents. Similarly, manipulation of the hippocampal endocannabinoid system, a strong modulator of neuronal activity, restore HFD-induced memory and plasticity alterations.

Altogether these results will highlight that adolescence represents a period of increased vulnerability to the effects of diet-induced obesity that may promote maladaptive cognitive processing later in life.