neuron cerebral giant cell A pair of symmetrical, giant, serotonin-containing neurones have been found in the cerebral ganglia of the pulmonate molluscs Limax, Ariolimax, Helix, Planorbis and Helisoma and the opisthobranch molluscs Aplysia, Tritonia and Pleurobranchaea and in the snail Lymnaea stagnalis. BTO:0004262 BrendaTissueOBO CGC cell