[Acetylcholinesterase activity in the nervous system of some Triclades (Planaria)]

By means of thiocholine method, ACHE activity has been revealed in cells of ganglia, ventral nerves, nervous plexuses of the pharynx and subepidermal layer of four planarian species. The products of ACHE activity appeared in the form of dark granules localized over cellular bodies and processes. Interspecific differences in the number and topography of ACHE-reactive cells were demonstrated.