The Extraction Of Swim Bladder Of Miiuy Croaker Collagen And It's Effect On Learning And Memory In Mice

Miiuy crocker (Miichthys miiuy) is an economical marine fish in East Asia. The swim bladder of miiuy crocker (SBM) is a traditional food for increasing immunity, enhancing brain function and promoting learning and memory. However, the effect of SBM on brain function has not been scientifically verified. In this study, we first isolated the SBM collagen (SBMC) by acid hydrolysis from the swim bladder of miiuy crocker. Based on SDS-PAGE and Macro-prep CM column chromatography, we characterized the SBMC as typeⅠcollagen with a chain composition of [α1 (Ⅰ)]2α2 (Ⅰ). The SBMC hydrolysates were orally administrated for 28 days, followed by the measurement of learning and memory in the Morris water maze. Learning and memory were significantly enhanced in the SBMC-treated mice, especially the mice with higher SBMC doses, compared with the control. However, the SBMC treatment did not change the swim speed and visual acuity for performance in the Morris water maze of mice, indicating that the function of SBMC on learning and memory are specific. After the performance of water maze, the mRNA expressions of learning and memory related genes in hippocampus were examined using real time-PCR, including the gene of NR2A, NR2B, BDNF and CREB. As a result, the mRNA expressions of these genes were up-regulated and also the ratio of NR2A/NR2B improved in SBMC-treated mice. These results may partially explained the reasons how SBMC enhanced the learning and memory. This study provides a kind of new prospective food to possibly enhance learning and memory in human.