Effects of Amino Acid Composition of Diet and Environment on RNA, Protein Content in Brain and Learning Ability in Rats

식이내 아미노산의 조성과 환경이 흰쥐의 두뇌중 RNA 단백질함량 및 학습능력에 미치는 영향

This study was performed to investigate the influence of the amino acid composition of diet and environment on RNA, protein content in brain and learning ability in rats. Forty-two Sprague-Dawley male rats were divided into six groups according to type of diet, casein, soybean meal, or corn gluten and rearing condition, isolated or enriched. They were fed foods ad libitum for 6 weeks. A water maze was used to test behavioral performance for 3 weeks from 4th week. The rats were sacrificed at 6th week and their whole brains were taken and frozen for assay of RNA and protein. The results were summarized as follows : 1) The body weight gain for the experimental periods of corn gluten group was significantly lower than the casein and the soybean meal group. 2) The brain weight of the corn gluten group was significantly lower than the casein and the soybean meal group and the environmental enrichment slightly increased it among rats fed the corn gluten diet. 3) The total RNA contents were the greatest in the environmentally enriched casein group. The brain protein contents of the isolated corngluten group was the smallest. However, the contents of the enriched corn gluten group were similar to those of the others. 4) In the water maze test, the isolated corngluten group spent significantly more time than the others. Environmental enrichment could decrease time to perform the task of the maze.