High-fat diet consumption for a short period sensitizes SNC to mild immune challenge and impaired contextual fear memory.

Carlos Paz, Córdoba, Argentina

Congreso; XXXIV Congress of the Argentine Society for Research in Neuroscience; 2019

Sociedad Argentina de Investigación en Neurociencias (SAN)

Hippocampal neuroinflammation normally increases with age, but risk of neuroinflammation, cognitive impairment and neurodegenerative diseases is exacerbated by chronic consumption of high fat diets (HFD), that could underlay an increase of pro-inflammatory cytokines. Also, consumption of HFD for a short time period has been shown to sensitize the inflammatory response to a subsequent immune challenge. Moreover, neuroinflammation and astrocytes activation and proliferation represent a common link between neurodegenerative diseases and metabolic related disorders. α-MSH is a potent anti-inflammatory peptide and previous results of our group indicated that α-MSH could reverse the effect of the neuroinflammation induce by IL-1β on memory consolidation and reconsolidation.Here, we explored whether short-term (5 days) consumption of HFD (60% of calories from fat) can trigger a neuroinflammatory response in male rats that received a mild immune challenge (LPS 10µg/Kg), leading to cognitive deficits. Ingestion of a HFD for 5 days did not impair fear contextual (hippocampal dependent) memory. However, the intraperitoneal injection of LPS, in a dose that did not produce changes in contextual memory by itself, impaired memory consolidation in HFD rats. The treatment with α-MSH (0.1µg/0.25µl) in dorsal hippocampus reversed the effect of short term HFD+LPS administration in contextual fear memory. We are also studying astrocytes proliferation and activation.In summary, our present results indicate that HFD consumption for a short period sensitizes SNC to mild immune challenge and produces an impairment in the contextual fear memory that could be related to changes in glial cells.