Figure 352 from Chapter 15 (Cytoplasmic Inclusions) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Glycogen concentrated in the presynaptic terminals of a mossy fiber from cerebellum of a winter turtle Chrysemys picta. Glycogen is relatively abundant in the brains of cold blooded vertebrates, especially in winter dormancy. Image by Enrico Mugnaini. A PDF copy of the accompanying chapter is available on the ASCB's BioEDUCATE website.