At low magnification you can make out the architecture of the spinal column. The stain used for these slides does not stain much except the neuronal cell bodies. Find the white matter, grey matter, central canal and ventral fissure. At the higher magnification you can see individual motorneurons. The nucleus doesn't stain (a negative image) except for the nucleolus, which is very distinct. The cytoplasm is filled with small dark structures called nissl bodies, which represent endoplasmic reticulum.