Brain synaptosomal aging: Free radicals and membrane fluidity

Choi, Jin-Ho; Yu, Byung Pal

doi:10.1016/0891-5849(94)00106-t

Cited by 145 publications

(74 citation statements)

References 37 publications

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“…In addition to PUFA, oxidative stress, which increases the level of free radicals [23], and which in turn induces a decrease in membrane fluidity [58], is yet another factor relevant for normal membrane composition. The incorporation of a restricted diet may overcome the damaging effects of the free radicals, and may offer a useful clinical intervention.…”

Section: Introductionmentioning

confidence: 99%

The role of polyunsaturated fatty acids in restoring the aging neuronal membrane

Yehuda¹,

Rabinovitz²,

Carasso³

et al. 2002

Neurobiology of Aging

353

200

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In addition to a gradual loss of neurons in various brain regions, major biochemical changes in the brain affect the neuronal membrane that is the "site of action" for many essential functions including long-term potentiation (LTP), learning and memory, sleep, pain threshold, and thermoregulation. Normal physiological functioning includes the transmission of axonal information, regulation of membrane-bound enzymes, control of ionic channels and various receptors. All are highly dependent on membrane fluidity, where rigidity is increased during aging. The significantly higher level of cholesterol in aging neuronal membrane, the slow rate of cholesterol turnover, and the decreased level of total polyunsaturated fatty acids (PUFA) may result from poor passage rate via the blood-brain barrier, or from a decreased rate of incorporation into the membrane, or a decrease in the activities of delta-6 and delta-9 desaturase enzymes. The added oxidative stress, which leads to an increase of free radicals leading to a decrease in membrane fluidity, may respond to a restricted diet, and thereby overcome the damaging effects of the free radicals. A central focus of this review is that a specific ratio of n-3/n-6 PUFA can restore many of these age-related effects.

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Section: Introductionmentioning

confidence: 99%

The role of polyunsaturated fatty acids in restoring the aging neuronal membrane

Yehuda¹,

Rabinovitz²,

Carasso³

et al. 2002

Neurobiology of Aging

353

200

View full text Add to dashboard Cite

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“…As summarized in Table 3, the same positive effect of FR on the physical-chemical properties of membranes was also demonstrated in other organs (23,(33)(34)(35)(36). Although in most of these studies membrane microviscosity was measured at a fixed temperature, the reported differences between AL and FR groups were so large that they cannot be compensated by the decrease of average body temperature occurring in FR animals.…”

Section: Studies On Membrane Microviscositymentioning

confidence: 67%

“…However, differences in membrane cholesterol content do not account for the difference in membrane microviscosity when comparing FR and AL-fed animals. In fact, it has been clearly shown that FR markedly attenuates the effect of age on fluidity without modulating the cholesteroltphospholipid ratios of the same membranes (23,35). However, as described below, FR selectively influences fatty acid composition in tissues as varied as liver (39)(40)(41), kidney (42), splenocytes, and bone marrow cells (43).…”

Section: Studies On Membrane Microviscositymentioning

confidence: 98%

Membrane properties and lipid peroxidation in food restricted animals

Pieri

1997

AGE

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Food restriction (FR) is a well-recognized method of extending mean and maximum longevity of rodents, but the mode of its action remains to be uncovered. This article reviews the effect of FR on the physicalchemical properties and lipid peroxidizability of cellular membranes. FR prevents the age-dependent increase in microviscosity and peroxidizability of cellular membranes. It has been suggested that a decrease in the body temperature occurring in undernourished animals may play a fundamental role in the process. Indeed, the lowering of average body temperature occurring in FR animals may induce a modification in membrane lipid composition, stimulating the cells to counteract the rigidifying effect of lower temperature. Thus, membranes are maintained in a proper functional state by a mechanism similar to that found in poikilotherm animals.

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“…On the basis of several experimental data, caloric restriction is currently claimed to modulate positively free radical metabolism by reducing the generation of reactive oxygen species and thus exerting its anti-aging effect (37)(38)(39). This action is of critical functional significance for the postmitotic nerve cells which are characterised by high lipid content and high oxygen consumption (40). On the basis of these concepts, a higher percentage of smaller junctional areas may be the outcome of the splitting of larger contact zones or of an improved preservation of the persisting contacts.…”

Section: Discussionmentioning

confidence: 99%

Dietary restriction modulates synaptic structural dynamics in the aging hippocampus

Bertoni–Freddari

Fattoretti

Caselli

et al. 1999

AGE

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A computer-assisted morphometric study has been carried out on the synaptic ultrastructural features in the hippocampus of 14-month old (DR14) and 27-month old (DR27) dietary restricted (-50% lipids and -35% carbohydrates) rats. Age-matched controls were maintained on an ad libitum (AL) feeding schedule. Synaptic numeric density (Nv), surface density (Sv) and average area (S) were the parameters measured. In old AL vs. adult AL animals, Nv decreased to a not significant extent, while S increased and Sv decreased significantly. In DR14 rats vs. AL littermates Nv increased significantly, but S and Sv were unchanged. DR27 rats vs. agematched AL controls showed a significant increase of Nv and Sv while S was significantly decreased. Comparing DR14 vs. DR27, no significant difference due to age was documented. Both in DR14 and in DR27 groups the percent distribution of S showed a marked increase of smaller contact zones. Despite reporting on discrete aspects of synaptic ultrastructure, Nv and S are supported to be in an inverse relationship which aims at maintaining Sv constant. Thus, these three ultrastructural parameters when taken together per experimental group, appear to provide information on synaptic morphological rearrangements. In this context, the percent increase of smaller synapses in DR animals is consistent with the idea of a marked remodelling process. Considering previous data from the same groups of rats reporting significant changes in neuronal membrane lipid composition and fluidity, we interpret our findings to account for a positive modulation of dietary restriction on the synaptic structural dynamics.

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Brain synaptosomal aging: Free radicals and membrane fluidity

Cited by 145 publications

References 37 publications

The role of polyunsaturated fatty acids in restoring the aging neuronal membrane

The role of polyunsaturated fatty acids in restoring the aging neuronal membrane

Membrane properties and lipid peroxidation in food restricted animals

Dietary restriction modulates synaptic structural dynamics in the aging hippocampus

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