Pronase action on the sheath surrounding ventral nerve cord ganglia in Bombyx mori L.

1. Pronase action on ventral nerve cord ganglia in Bombyx mori L. larvae has been studied from different points of view. 2. Microelectrode penetration in the nervous cell is facilitated by exposure of the tissue to the enzyme. 3. Ultrastructural observations show that pronase action affects mainly the fibrous sheath of the tissue, leading to a partial desheathing of the ganglion. 4. Pronase treatment does not affect significantly the ionic concentrations in the nerve cord.