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Title: Dietery walnut alters neurochemical and behavioral functions in young and old rats

Author
item Poulose, Shibu
item Fisher, Derek
item MILLER, MARSHALL - Jean Mayer Human Nutrition Research Center On Aging At Tufts University
item BIELINSKI, DONNA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University
item Ramirez, Francisco
item Shukitt-Hale, Barbara

Submitted to: Society for Neuroscience Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 6/25/2013
Publication Date: 11/9/2013
Citation: Poulose, S.M., Fisher, D.R., Miller, M.M., Bielinski, D.F., Ramirez, F., Shukitt Hale, B. 2013. Dietery walnut alters neurochemical and behavioral functions in young and old rats. Society for Neuroscience Abstracts and Proceedings. 2013. Program #252.02.

Interpretive Summary:

Technical Abstract: Diets rich in either polyunsaturated fatty acids or polyphenols have been shown to promote indices of brain functions, primarily with effects on the lipid microenvironment or neuronal signaling. Walnuts are known to contain high amounts of omega fatty acids such as alpha linoleic acid (ALA) and linolenic (LA), as well as neuroactive polyphenols and minerals. Previous studies from our laboratory have shown that feeding diets rich in walnuts protected against age-associated behavioral declines in rats, primarily via enhancing protective signaling, reducing inflammation and preventing accumulation of ubiquitinated inclusion bodies in key regions of the brain. In order to assess whether walnut diets affect age-associated changes in the epigenetic phenomenon, young (3 month) and old (18 month) rats were fed with walnut diets at concentrations of 0%, 6% or 9% w/w for 12 weeks, and subjected to a battery of motor and cognitive tests. Blood serum was collected to test for its exogenous protective effects at the beginning (baseline) and end of the feeding period. Brains were collected to examine global DNA methylation as well as gene-specific DNA methylation patterns in key areas of the brain affecting behavior. The behavioral tests showed significant effects of age. Positive effects of the diet were seen for the wire suspension test, with both 6% and 9% walnut groups performing significantly better than controls. The walnut-fed rats also made fewer errors in the radial arm water maze. BV2 microglial cells treated with serum from walnut-fed animals and then exposed to the endotoxin lipopolysaccharide (LPS) showed reduced stress-induced inflammatory signals compared to serum from control-fed rats. A correlation of serum effects from respective animals to their behavior is being done along with differential epigenetic patterns. Overall results indicate long-term benefits of a walnut diet rich in both polyphenols and omega fatty acids.