Effects of dietary fish oil on learning function and apoptosis of hippocampal pyramidal neurons in streptozotocin-diabetic rats

• Published in: Brain research 2012-05, Vol.1457, p.33-43
• Main Authors: Zhao, Chang-Hai, Liu, Han-Qiang, Cao, Rui, Ji, Ai-Ling, Zhang, Lei, Wang, Feng, Yang, Rui-Hua
• Format: Article
• Language: English
• Subjects: Adjuvants; Analysis of Variance; Animals; Apoptosis; Apoptosis - drug effects; Avoidance Learning - drug effects; Bax protein; bcl-2-Associated X Protein - metabolism; Biological and medical sciences; Blood Glucose - drug effects; Body Weight - drug effects; Caspase 3 - metabolism; Caspase-3; Diabetes; Diabetes mellitus; Diabetes Mellitus, Experimental - complications; Diabetes Mellitus, Experimental - diet therapy; Diabetes Mellitus, Experimental - pathology; Diabetes. Impaired glucose tolerance; diabetic complications; dietary fat; Dietary Supplements; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Fatty acids; Fish oil; Fish oils; Fish Oils - administration & dosage; Gene Expression Regulation - drug effects; Hippocampus; Learning; Learning and memory; Learning Disorders - diet therapy; Learning Disorders - etiology; Locomotion - drug effects; Male; Maze Learning - drug effects; Medical sciences; Memory; Microscopy, Electron, Transmission; Neurology; Neurons; Polyunsaturated fatty acid; Polyunsaturated fatty acids; Proto-Oncogene Proteins c-bcl-2 - metabolism; Pyramidal cells; Pyramidal Cells - drug effects; Pyramidal Cells - ultrastructure; Pyramidal neuron; Rats; Rats, Sprague-Dawley; Reaction Time - drug effects; Spatial discrimination learning; spatial memory; Streptozocin; streptozotocin; therapeutics; Time Factors
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2012.03.067

Abstract Previous research has demonstrated that diabetes induces learning and memory deficits. However, the mechanism of memory impairment induced by diabetes is poorly understood. Dietary fatty acids, especially polyunsaturated fatty acids, have been shown to enhance learning and memory and prevent memory deficits in various experimental conditions. The present study investigated the effects of fish oil supplementation on the neuron apoptosis in the hippocampus of streptozotocin (STZ)-induced diabetes rats. The effects of diabetes and fish oil treatment on the spatial learning and memory were also evaluated using the Morris Water Maze. Diabetes impaired spatial learning and memory of rats. Diabetes increased the expression of Bax and caspase-3, which led the apoptosis of the CA1 pyramidal neurons, and further contributed to the deficits in learning and memory processing. Fish oil dietary supplementation in diabetic rats conducts neuron-protective function through an anti-apoptotic pathway and significantly improves the ability of learning and memory. These results partially explain the mechanism of the effect of diabetes and fish oil treatment on learning and memory, supporting a potential role for fish oil as an adjuvant therapy for the prevention and treatment of diabetic complications.