x-linolenic acid dietary deficiency alters age-related changes of dopaminergic and serotoninergic neurotransmission in the rat frontal cortex.
x-linolenic acid dietary deficiency alters age-related changes of dopaminergic and serotoninergic neurotransmission in the rat frontal cortex.
Year: 1996
Authors: S Delion, S Chalon, D Guilloteau, J C Besnard, G Durand.
Publication Name: J. Neurochem.
Publication Details: Volume 66; 1582.
Abstract:
A progressive deterioration in CNS function including alterations in neurophysiological processes and memory deficits has been shown with aging. These changes are associated with monoaminergic neurotransmission systems involving dopamine and serotonin neuronal markers. Modifications in cell membrane lipid composition with subsequent alterations in membrane fluidity and function have been described in aging rats. It has been reported that ALA deficient diets alter the FA composition of the brain and lead to reductions in DHA. Chronic ALA deficiency has also been associated with alterations in monoaminergic neurotransmission which may explain cognitive and behavioral deficits experienced in animals fed such diets. This data suggests a relationship between modifications in brain lipid composition, alterations in monoaminergic function and cognitive and behavioral deficits that occur in both n-3 deficient rats and in aging. In this study, the effects of an ALA diet deficiency on rat dopaminergic and serotoninergic neurotransmission systems were investigated in the frontal cortex, striatum, and cerebellum of male rats 2, 6, 12 and 24 months of age. ALA deficiency resulted in a severe decrease in DHA levels and an increase in n-6 fatty acids in all regions of the brain. A recovery in the levels of DHA was observed in deficient rats between 2 and 12 months of age which did not continue past 12 months of age. The recovery in DHA levels was lower in frontal cortex than in striatum and cerebellum. In the striatum and the cerebellum, dopaminergic and serotoninergic receptor densities and endogenous dopamine and serotonin levels were affected by aging regardless of the diet. In contrast, a 40-75% lower level of endogenous dopamine in the frontal cortex occurred in ALA deficient rats. The authors suggested that this finding is significant because cortical areas of the brain are involved in behavioral processes such as memory and attention. ALA deficiency resulted in an 18-46% increase in serotonin 5-HT2 receptor density in the frontal cortex during aging, without changes in endogenous serotonin levels. ALA deficiency also resulted in a 10% reduction in density of dopaminergic D2 receptors. The authors concluded that their data suggests that a chronically ALA-deficient diet specifically affects the monoaminergic systems in the frontal cortex which may have significant negative effects on behavioral processes such as memory and attention. The data supports ALA supplementation in the diets of individuals who consume small amounts of omega 3 fatty acids.
