Mapping of nerve cells in the suboesophageal ganglia of Helix aspersa

Abstract

Abstract o 1. More than 100 different neurones have been investigated in three suboesophageal ganglia (left parietal, visceral and right parietal ganglia) of the snail Helix aspersa . 2. Diagrams and photographs of the ganglia are presented so that the cells may be identified and localized. 3. The responses following stimulation of the main peripheral nerve trunks are analysed and described, in terms of EPSP, IPSP and antidromic potentials. 4. The cells' responses to iontophoretic application of acetylcholine, dopamine, 5-HT and glutamate are described. The majority of responses to the drugs are as follows: H to ACh; H to dopamine; H to 5-HT and D to glutamate. 5. The anatomical position, spontaneous electrical activity and responses to stimulation of the main peripheral nerves and drug application make it possible to identify specific nerve cells from preparation to preparation. 6. The axons from some cells have been traced following intracellular injections of CoCl 2 and precipitation of CoS. This supported the electrophysiological method of tracing axons by recording antidromic spikes in the cell body following stimulation of a peripheral nerve. 7. It is suggested that some of the nerve cells will be homologous with other nerve cells throughout the Gastropod Molluscs.