Synapses between neurons regenerate accurately after destruction of ensheathing glial cells in the leech.

Individual glial cells that ensheathe axons in the central nervous system of the leech were destroyed by intracellular injection of protease. The axons were then severed, and regeneration by particular neurons was studied physiologically and morphologically. Although certain axons sprouted more in the absence of the glial cell, functional synapses were accurately regenerated with normal frequency.