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Figure 2. Nucleolar membrane and nucleolonema in isolated rabbit lateral vestibular neuron(phase contrast, x 1200), from Hillman and Jarman (1991).A nucleolar membraneHydén (1959) took out cells bodies in 0.25 M sucrose solution, but, Hinton, Burge andHartman (1969) showed that sucrose inhibits a number of enzymes, so we decided to dissect outour cells in Krebs-Ringer bicarbonate buffered saline, or in normal saline. When we did this, wenoticed that the cell bodies became much more translucent. The nucleolus became much clearer,and the nucleolonema could be seen. This is a strand within the nucleolus first seen by lightmicroscopy in 1951 by Estable and Sotelo. It has almost disappeared from the literature, sincethe electron microscope was introduced, although it is occasionally seen as a blob. In our unfixedcell bodies, the nucleolonema could be seen moving around the nucleolus slowly,and occasionalpieces broke off and escaped into the nucleus (Sartory, Fasham and Hillman, 1971). Thesemovements ceased when 10% formalin was applied to the cells. As the nucleolus could now beseen clearly, we detected around it a nucleolar membrane in neurons from all the rabbit, rat,guinea pig, frog and human cells we examined (Hussain, Hillman and Sartory, 1974; Hillmanand Jarman, 1991, pps 23, 24, 53, 54) (Figure 2). We have also shown it as a demonstration atseveral meetings of the Physiological Society. At one place, J.R. Baker saw it, and agreed withour observation and our interpretation. When the cells are taken out in 0.25 M sucrose, or are14