Cytochemical investigations on the localization of 5'-nucleotidase in the rat hippocampus with special reference to synaptic regions.

The fine structural localization of the 5'-nucleotidase was investigated in the CA3 region of the rat hippocampus. The attention was focussed on the occurrence of the enzyme in the synaptic region. The 5'-nucleotidase activity was demonstrated at the surface membranes of axons and dendrites. Prominent portions of enzyme activity were detectable in the nuclei and the nuclear envelope, whereas the cytoplasmic organelles were nearly devoid of reaction product. In synapses five types of 5'-nucleotidase localization were revealed. A participation of the enzyme in the process of neurotransmission is discussed.