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DOCOSAHEXAENOIC ACID‐INDUCED PROTECTIVE EFFECT AGAINST IMPAIRED LEARNING IN AMYLOID β‐INFUSED RATS IS ASSOCIATED WITH INCREASED SYNAPTOSOMAL MEMBRANE FLUIDITY
Author(s) -
Hashimoto Michio,
Hossain Shahdat,
Shimada Toshio,
Shido Osamu
Publication year - 2006
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.2006.04467.x
Subject(s) - membrane fluidity , chemistry , phospholipid , endocrinology , docosahexaenoic acid , medicine , lipid peroxidation , membrane , biophysics , fluorescence anisotropy , biochemistry , fatty acid , oxidative stress , polyunsaturated fatty acid , biology
SUMMARY1 In the present study, we investigated the relationship between the docosahexaenoic acid (DHA)‐induced protection of learning deficit of amyloid β (1−40) ‐infused Alzheimer's disease (AD) model rats and changes in synaptosomal plasma membrane fluidity of the cerebral cortex. 2 Synaptosomal membrane lateral and rotational fluidity were measured using pyrene excimer spectroscopy and fluorescence polarization of 1,6‐diphenyl‐1,3,5‐hexatriene (DPH), respectively. 3 Avoidance learning ability, as assessed by a two‐way active avoidance paradigm, decreased significantly in the AD model rats. 4 Pyrene‐determined annular/non‐annular fluidity ratio and the DPH‐determined bulk fluidity of the synaptosomal plasma membrane decreased in the amyloid β (1−40) ‐infused rats. Oral pre‐administration of DHA (300 mg/kg per day for 12 weeks) significantly increased both lateral and rotational fluidity. 5 The synaptosomal membrane DHA content increased and the cholesterol to phospholipid molar ratio and lipid peroxidation decreased. 6 The annular to non‐annular fluidity ratio of the synaptic plasma membrane was positively correlated with total avoidance learning. 7 The present results indicate that DHA‐induced alterations in synaptic plasma membrane fluidity may contribute to the synaptic plasma membrane‐related functions that constitute avoidance learning‐related memory in amyloid β (1−40) ‐infused rats.