Abstract:

This study was aimed to investigate the effect of docosahexaenoic acid on learning and memory abilities in rats
and to explore the relevant molecular mechanism. A total of 32 neonatal male SD rats were randomly divided into 4 groups:
negative control group, positive control group, low (370 mg/(kg·d)) and high dose DHA group (740 mg/(kg·d)). After
8 weeks of feeding, the enzyme activities of acetylcholinesterase (AChE) and nitric oxide synthase (NOS) in brain tissue
of rats were analyzed. The mRNA expressions of N-methyl-D-aspartate receptor subunit (NR1), cAMP responsive element
binding protein (CERB), immediate early gene (c-fos) in the hippocampus of rats were determined by RT-PCR. Results
showed that compared to the negative control group, DHA at both doses was able to significantly increase AChE and NOS
activities in brain tissue as well as the mRNA expression levels of NR1, CREB and c-fos while the low dose presented
higher effect. In summary, DHA could remarkably improve learning and memory abilities in rats in a dose-dependent
manner. The mechanism might be involved with the upregulation of NR1, CREB and c-fos mRNA expression by DHA in the
hippocampus of rats.

Key words: DHA, learning and memory, N-methyl-D-aspartate receptor, cAMP responsive element binding protein, c-fos