[Morphologic changes in the axo-dendritic synapses of the leech following excitatory conduction block in a medium...

Reactive changes in the synaptic apparatus of the leech neuropile were studied in low ionic strength media using supravital methylene blue staining. Special preparation developed in the laboratory permitted obtaining clearly identified axodendritic synapses in the leech. It was shown that the reactive changes were pronounced during a decrease in the electrical conductance and block in the abdominal chain. Certain correlations between the structural alterations in axodendritic synapses and phasic reactive changes in axosomatic synapses were observed.