ON THE NATURE AND DIFFERENTIAL DISTRIBUTION OF MESSENGER-RNAS IN HIPPOCAMPAL NEURITES - IMPLICATIONS FOR NEURONAL FUNCTIONING

Neurons are highly polarized cells with a mosaic of cytoplasmic and me mbrane proteins differentially distributed in axons, dendrites, and so mata. In Drosophila and Xenopus, mRNA localization coupled with local translation is a powerful mechanism by which regionalized domains of s urface or cytoplasmic proteins are generated. In neurons, there is sub stantial ultrastructural evidence positing the presence of protein syn thetic machinery in neuronal processes, especially at or near postsyna ptic sites. There are, however, remarkably few reports of mRNAs locali zed to these regions. We now present direct evidence that an unexpecte dly large number of mRNAs, including members of the glutamate receptor family, second messenger system, and components of the translational control apparatus, are present in individual processes of hippocampal cells in culture.