Department of Nutrition and Food Hygiene, The Ministry of Education Key Laboratory of Hazard Assessment and Control in Special Operational Environment, School of Public Health, The Fourth Military Medical University, Xi'an 710032, PR China.
Neuroscience. 2012 Jun 14;212:93-103. doi: 10.1016/j.neuroscience.2012.04.005. Epub 2012 Apr 16.
Previous research has demonstrated that diabetes induced learning and memory deficits. However, the mechanism of memory impairment induced by diabetes is poorly understood. Dietary fatty acids, especially polyunsaturated fatty acids (PUFA), have been shown to enhance learning and memory and prevent memory deficits in various experimental conditions. Sprague-Dawley rats were used in the present study to investigate the effect of fish oil supplementation on spatial learning and memory of streptozotocin (STZ)-induced diabetic rats with the Morris Water Maze. The excitability of CA1 pyramidal neurons and the related ionic currents was also examined. Diabetes impaired spatial learning and memory of rats. Diabetes decreased the sodium currents and increased the potassium currents, and further led to the reduction of excitability of CA1 pyramidal neurons, effects which may contribute to the behavioral deficits. Fish oil dietary supplementation decreased the transient currents and Kv4.2 expression in the hippocampus and partially improved learning performance of diabetic rats. The results of the present study suggested that sodium and potassium currents contributed to the inhibitory effect of diabetes on neuron excitability, further influencing learning and memory processing. Dietary fish oil may modulate the membrane excitability and is a possible strategy for preventing the impairments of diabetes on hippocampal function.
先前的研究表明，糖尿病可导致学习和记忆缺陷。然而，糖尿病引起记忆损伤的机制尚不清楚。膳食脂肪酸，尤其是多不饱和脂肪酸（PUFA），已被证明可增强学习和记忆，并预防各种实验条件下的记忆缺陷。本研究采用 Sprague-Dawley 大鼠，通过 Morris 水迷宫实验，探讨了鱼油补充对链脲佐菌素（STZ）诱导的糖尿病大鼠空间学习和记忆的影响。还检查了 CA1 锥体神经元的兴奋性及其相关离子电流。糖尿病损害了大鼠的空间学习和记忆能力。糖尿病降低了钠电流，增加了钾电流，进而导致 CA1 锥体神经元兴奋性降低，这些效应可能导致行为缺陷。鱼油饮食补充降低了海马中的瞬变电流和 Kv4.2 表达，并部分改善了糖尿病大鼠的学习表现。本研究结果表明，钠电流和钾电流有助于糖尿病对神经元兴奋性的抑制作用，进一步影响学习和记忆处理。膳食鱼油可能调节膜兴奋性，是预防糖尿病对海马功能损伤的一种可能策略。
