APLYSIA HEMOLYMPH PROMOTES NEURITE OUTGROWTH AND SYNAPTOGENESIS OF IDENTIFIED HELIX NEURONS IN CELL-CULTURE

Hemolymph of adult Aplysia californica significantly affects neurite o utgrowth of identified neurons of the land snail Helix pomatia. The me tacerebral giant cell (MGC) and the motoneuron C3 from the cerebral ga nglion and the neuron B2 from the buccal ganglion of H. pomatia were i solated by enzymatic and mechanical dissociation and plated onto poly- l-lysine-coated dishes either containing culture medium conditioned by Helix ganglia, or pre-treated with Aplysia hemolymph. To determine th e extent of neuronal growth we measured the neurite elongation and the neuritic field of cultured neurons at different time points. Aplysia hemolymph enhances the extent and race of linear outgrowth and the bra nching domain of Helix neurons. With the hemolymph treatment the MGC n euron more consistently forms specific chemical synapses with its foll ower cell B2, and these connections are more effective than those esta blished in the presence of the conditioned medium.