Peptidergic and aminergic centers in the Helix cerebral ganglia: somatotopy and immunocytochemistry.

In Helix cerebral ganglia the relationship between location of serotonin, dopamine, CARP, FMRFamide, Met-enkephalin, and substance P immunoreactive neurons and the different representation foci of the head areas was compared. The majority of immunoreactive neurons was located in representation foci, however, the extension of immunoreactive centers are larger than the representation foci. Therefore, the real extension of a representation focus with the additional non-efferent neurons might be larger than revealed by retrograde labelling.