Somatotopic representation of the head areas in the cerebral ganglion of the snail Helix pomatia.

This study gives a detailed description of the central representation of the head regions in the cerebral ganglion after parallel nickel-lysine and cobaltic-lysine backfilling of different pairs of cerebral nerves. The backfilling of the cerebral nerves demonstrate different groups of labelled neurons in the cerebral ganglion as in the procerebrum, mesocerebrum, metacerebrum, as well as in the pleural, pedal and commissural lobes of the postcerebrum. Each head area except the anterior and posterior tentacle is represented in each labelled cell group. The tentacles are not represented in the mesocerebrum and the pedal lobe of the post-cerebrum. The different head areas in the procerebrum, metacerebrum and the pleural lobe are represented in fronto-caudal a somatotopic order.