The effect of diet upon the fatty acid composition of cranial and spinal nerve lipids.

The possible basal differences in lipid class and fatty acid composition between a cranial nerve (the trigeminal nerve) and two spinal nerves (the ulnar and sciatic nerves) as well as the effects of dietary lipids on the same nerves were studied. A basal (BD) and four experimental diets containing respectively hydrogenated coconut oil (HCO), grapestone oil (GSO), olive oil (OO) and linseed oil (LSO) were used. Trigeminal lipids fatty acid composition differs significantly from sciatic and ulnar ones in the percentages of 16:0, 16:1, 18:0, 18:2 n-6, 20:0, 20:1, 20:4 n-6, 24:0, 24:1 and 22:6 n-3. Also the proportions of triacylglycerols and free cholesterol strongly differ in trigeminal and spinal nerves whereas no significant difference was detected between ulnar and sciatic nerve lipids. Following the administration of the four experimental diets for 60 days, no significant change was observed in the fatty acid pattern of trigeminal lipids while the spinal ones showed a significant increase in the proportions of the fatty acids present in large quantities in the dietary oils used (i.e.: oleic acid in the OO samples). These changes are probably linked with the rapid metabolic turnover of triacylglycerols, present in larger amounts in spinal nerve lipids.