Marine omega-3 polyunsaturated fatty acids induce sex-specific changes in reinforcer-controlled behaviour and neurotransmitter metabolism in a spontaneously hypertensive rat model of ADHD

Profesjonsstudent Torbjørn H. Sandvik, har sammen med Terje Sagvolden, Kine S.Dervola, Bjørg Å. Roberg, Grete Wøien, Inger Lise Bogen, Christian A. Drevon, Espen Borgå Johansen og Sven Ivar Walaas skrevet en artikkel i Behavioral and Brain Functions

Abstract

Background: Previous reports suggest that omega-3 (n-3) polyunsaturated fatty acids (PUFA) supplements may reduce ADHD-like behaviour. Our aim was to investigate potential effects of n-3 PUFA supplementation in an animal model of ADHD.

Methods: We used spontaneously hypertensive rats (SHR). SHR dams were given n-3 PUFA (EPA and DHA)-enriched feed (n-6/n-3 of 1:2.7) during pregnancy, with their offspring continuing on this diet until sacrificed. The SHR controls and Wistar Kyoto (WKY) control rats were given control-feed (n-6/n-3 of 7:1). During postnatal days (PND) 25-50, offspring were tested for reinforcement-dependent attention, impulsiveness and activity as well as spontaneous locomotion. The animals were then sacrificed at PND 55-60 and their neostriata were analysed for monoamine and amino acid neurotransmitters with high performance liquid chromatography.

Results: n-3 PUFA supplementation significantly enhanced reinforcement-controlled attention and reduced lever-directed activity and impulsiveness in SHR males whereas the opposite or no effects were observed in females. Analysis of neostriata from the same animals showed significantly enhanced dopamine and serotonin turnover ratios in the male SHRs, whereas female SHRs showed no change, except for an intermediate increase in serotonin catabolism. In contrast, both male and female SHRs showed n-3 PUFA-induced reduction in non-reinforced spontaneous locomotion, and sex-independent changes in glycine levels and glutamate turnover.

Conclusions: Feeding n-3 PUFAs to the ADHD model rats induced sex-specific changes in reinforcement motivated behaviour and a sex-independent change in non-reinforcement associated behaviour, which correlated with changes in presynaptic striatal monoamine and amino acid signalling, respectively. Thus, dietary n-3 PUFAs may partly ameliorate ADHD-like behaviour by reinforcement-induced mechanisms in males and partly via reinforcement insensitive mechanisms in both sexes.

Behavioral and Brain Functions, 2012, DOI:10.1186/1744-9081-8-56

Published Dec. 21, 2012 8:45 AM