Ramon-y-Cajal made drawings by injecting neurons with dye. The dye spread within the cell but could not cross the cell membrane. Neurons are naturally transparent and tightly packed together. Without a stain of some kind, one cannot see much in nervous tissue, using a light microscope. clenbuterol reviews With his dye injection technique, Cajal was able to see complex neural processes (dendritic trees and axonal arborizations) using only a light microscope. It is packed full of structures too small for scientists of Cajal’s era to see, including the cell’s nucleus, which regulates many aspects of the cell’s activity. The little black blob is the cell body or soma of the neuron. It is packed full of structures too small for scientists of Cajal’s era to see, including the cell’s nucleus, which regulates many aspects of the cell’s activity.
The gaps between neurons are so tiny that in the 1890s there was a tremendous controversy over whether the nervous system formed a continuous network (the reticular theory) or whether it consisted of separate cells (what was then called the neurone theory). Cajal finally resolved the issue. He showed that neurons were distinct cells, separated by gaps that—in those days—were too tiny for clenbuterol reviews microscopes to see.