Function and regulation of the pentose phosphate pathway in brain

Although the quantitative contribution of the pentose phosphate pathway to glucose metabolism in adult brain is small, numerous experiments using specific inhibitors and developmental studies (Table VI) confirm the importance and the "functional" role of this pathway in brain (for details, see reviews by Baquer et al., 1975, 1977). In this article, an attempt has been made to bring together the important findings regarding the localization, operation, and functional significance of the pentose phosphate pathway in nervous tissue. The presence of these enzymes in synaptosomes and their linkage with peroxidative mechanisms, monoamine oxidase, and glutathione pathways suggest that they may be serving an important role in brain in vivo. There are a number of aspects that require further study for an understanding of the role of the pentose phosphate pathway in brain, including its role in inhibitory and excitatory synapses, in the control of synaptic plasticity, and the relationship between the electroencephalogram and the pentose phosphate pathway in various neural populations.