Effect of short term high-fat diet in contextual fear memory and structural plasticity. Possible modulation by alpha-melanocyte stimulating hormone (α-MSH).

LASAGA M; SCIMONELLI T; HERRERA G

Congreso; Reunion Anual de la SAN 2021; 2021

SAN

Cognitive deficit and neurodegenerative diseases are associated with age, however environmental factors such as chronic consumption of a high-fat diet (HFD) aggravate them in young and adults. The effects of HFD on the central nervous system could be related to neuroinflammation, and consumption of HFD for a short period of time can exacerbate the inflammatory response to a mild immune challenge. Alpha-melanocyte stimulating hormone (α-MSH) mediates antiinflammatory and neuroprotective actions. We explored whether short-term (5 days) HFD consumption plus a mild immune challenge (LPS) would serve as a neuroinflammatory trigger, leading to cognitive deficits and possible changes in hippocampal structural plasticity. Our results show that short-term HFD does not affect body weight, however, produces change in total cholesterol. HFD impaired contextual fear (hippocampal dependent) memory in rats that received LPS (10µg/Kg). Besides, it was associated with a decrease in spine density in the dorsal hippocampus (DH). The treatment with α-MSH (0.1ug/0.25ul) in the DH reversed the effect of short-term HFD in both contextual fear memory and in spine density.Our present results indicate that HFD consumption for a short period sensitizes SNC to a subsequent immune challenge and produces impairment in the contextual fear memory that could be related to changes in hippocampal structural plasticity. α-MSH could have a protective effect.