Fig. 7.1.36. These clusters (arrows) containing finely granulofilamentous material
are found either attached to granular endoplasmic reticulum, to postsynaptic densities, or
lying freely in the cytoplasm (inset). We do not know what their composition and significance
exactly are. However, according to their appearance, they perhaps could represent either
so called "RNA granules" containing mRNA and ribosomes (according to
Knowles et al., 1996, J Neurosci 16:7812-7820, similar formations represent a way by
which a specific mRNA and polyribosomes are transported from neuronal soma to dendrites
and their postsynaptic regions), or they could be a specific form of CaMKII protein kinase
(Dosemeci et al., 2000, J Neurosci 20:3076-3084).
Scale = 100 nm. (Human, neocortex.)
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