N-3 fatty acid deficiency induced by a modified artificial rearing method leads to poorer performance in spatial learning tasks

• Published in: Pediatric research Vol. 58; no. 4; pp. 741 - 748
• Main Authors: LIM, Sun-Young, HOSHIBA, Junji, MORIGUCHI, Toru, SALEM, Norman
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 01.10.2005
• Subjects: Animal Nutritional Physiological Phenomena; Animals; Animals, Newborn; Arachidonic Acid - metabolism; Biological and medical sciences; Body Weight; Brain - metabolism; Docosahexaenoic Acids - metabolism; Fatty Acids, Omega-3 - metabolism; Fatty Acids, Omega-3 - pharmacology; Female; General aspects; Learning; Lipids - chemistry; Maze Learning; Medical sciences; Memory; Rats; Rats, Long-Evans; Spatial Behavior; Time Factors; Performance evaluation; Parental behavior; Pediatrics; Methodology; Deficiency; Polyunsaturated fatty acid; Lipids; Method; n-3 fatty acid; Learning; Acquisition process; Unsaturated fatty acid; Rearing; Mechanism of action; Performance
• ISSN: 0031-3998; 1530-0447
• DOI: 10.1203/01.pdr.0000180547.46725.cc

Docosahexaenoic acid (DHA) is a major structural component of the nervous system, and depletion may lead to losses in neural function. Our objective was to demonstrate a deficit in spatial task performance in rats with low brain DHA due to a low n-3 fatty acid intake using a first-generational artificial rearing technique. Newborn rat pups were separated on d 2 and assigned to two artificial rearing groups or a dam-reared control group. Pups were hand fed artificial milk via custom-designed nursing bottles containing either 0.02% (n-3 Def) or 3.1% (n-3 Adq) of total fatty acids as LNA. At d 21, rats were weaned to either n-3 Def or n-3 Adq pelleted diets and several behavioral tasks were evaluated at 9 wk of age. Brain DHA was lower (58% and 61%, p < 0.001) in n-3 Def in comparison to n-3 Adq and dam-reared rats, respectively. At adulthood, the n-3 fatty acid-deficient rats had a significantly greater moving time than the dam-reared group (p < 0.05), but there were no differences among the three groups in the elevated plus maze test. The n-3 fatty acid deficient rats exhibited a longer escape latency (p < 0.05) and poorer memory retention in the Morris water maze compared with n-3 fatty acid adequate and dam-reared rats. We concluded that artificial rearing can be used to produce n-3 fatty acid deficiency in the first generation. This deficiency was associated with significantly reduced spatial learning. Adequate brain DHA levels are required for optimal spatial learning.