Morphological and electrophysiological mapping of giant neurons in the suboesophageal ganglia of Helix pomatia

1. 1. To reveal the morphology of the suboesophageal ganglia of Helix pomcitia, the connective tissue was completely removed and the preparations stained whole-mount with methylgreen-pyronin G to display the relative locations of the neurons. 2. 2. Fifteen large cells which could be recognized as individuals in at least 75% of the preparations investigated, were morphologically identified by size, position and color. 3. 3. The cells were electrophysiologically characterized with respect to spontaneous activity, synaptic input from peripheral nerves, and response to application of drugs (e.g. ACh, DA and 5-HT). 4. 4. The peripheral axonal projections of eight of the major identified cells were investigated by intracellular CoCl2 injection and by cobalt backfillings of the peripheral nerves.