Abstract

INTRODUCTION

Regional and developmental data from rat

Ascorbate content and neuron density

Summary and significance

References

Discussion
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Compartmentalization of brain ascorbic acid (ascorbate) and glutathione (GSH) between neurons and glia has been a source of controversy. To address this question, we determined the ascorbate and GSH content of brain tissue with varying, but defined densities of neurons and glia. In developing rat cortex, GSH content rose during gliogenesis, while ascorbate fell. By contrast, in developing cerebellum, ascorbate, but not GSH, increased markedly during granule cell proliferation. In adult cortex, ascorbate content increased linearly with increasing neuron density in tissue from various species, with human < rabbit < guinea pig < rat < mouse. GSH content was species-independent. Taken together, these data permitted calculation of concentrations of ascorbate in neurons (10 mM) and glia (0.9 mM) and GSH in neurons (2.5 mM) and glia (3.8 mM). The high concentration of ascorbate in neurons suggests that it is a key component of the neuronal antioxidant network. It is often a neglected component, as well. The improved understanding of the neuronal antioxidant network afforded by these data should give new direction to the study of neurological disorders linked to oxidative stress, including cerebral ischemia and Parkinson's disease.

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Presentation Number SArice0783
Keywords: ascorbate, glutathione, neurons, glia, oxidative stress