LOCALIZATION OF AN EXTRACEREBRAL NSV-GANGLION IN THE CEPHALOPOD, SEPIA-OFFICINALIS

The neurosecretory system of the vena cava (NSV) of Sepia officinalis contacts the palliovisceral lobe with some axons that run parallel to the visceral nerves. Distal to the palliovisceral lobe the NSV-system widens to form a hitherto unknown extracerebral ganglion containing ap proximately 4200 perikarya. This is regarded as the primary origin of neurotransmitters. Distal to this nucleus area the volume and the numb er of cell bodies in the NSV-system is reduced. It contains neurosecre tory nerve cells, two glial cell types, large cell accumulations, conn ective tissue and capillaries. Histochemical, immunohisto- and immunoc ytochemical examinations show the existence of catecholamines, and the coexistence of serotonin and FMRFamide in the NSV-System. A HPLC anal ysis differentiated between dopamine, noradrenaline, and adrenaline.