Cajal Body - History

History

CBs were initially discovered by neurobiologist Santiago Ramón y Cajal in 1903 as small argyrophilic spots in nuclei of silver-stained neuronal cells. Because of their close association with nucleoli he named them nucleolar accessory bodies. Later on, they were forgotten and rediscovered multiple times independently which led to a state where scientists from different research fields used different names for the same structure. Names used for CBs included "spere organelles", "Binnenkörper", "nucelolar bodies" or "coiled bodies". The name coiled bodies comes from observation of electron microscopists Monneron and Bernhard. They described bodies as aggregates composed of coiled threads with thickness of 400-600 Å. When using higher magnification, they appear as tiny, 50 Å thick fibrils irregularly twisted along the axis of the threads. The bodies were even predicted to consist of ribonucleoproteins since treatment of cells with protease and RNase together, but not alone, caused dramatic changes to the structure of CBs.