[Histochemical study of the cholinesterase in the olfactory bulb of the frog, Rana temporaria]

In the olfactory bulb of Rana temporaria the distribution of cholinesterase was studied by the method of Karnovsky and Roots. When the butyrilthiocholine was used as a substrate the histochemical reaction was not obtained. The incubation with the acetylthiocholine showed the enzyme activity that was most pronounced in the mitral cells layer and in the nerve fibers area surrounding the granular cells layer. The addition of neostigmine to the incubation medium abolished the enzyme activity.