INVITRO CONNECTIONS BETWEEN LYMNAEA AND HELISOMA IDENTIFIED INTERNEURONS AND THEIR FOLLOWER CELLS

The mechanisms that underly the specificity of synaptic connections ar e poorly understood. In this study we used two homologous interneurons , the giant dopamine cell. (GDC), in two species of pond snails, Lymna ea and Helisoma. We examined the ability of the Lymnaea GDC to form sp ecific synapses with known follower or non-follower cells in vitro. Si milar tests were performed for the Helisoma GDC. Both of these interne urons form appropriate connections not only with homologous follower n eurons, but also with follower neurons from the alternative species. T hese results suggest that common mechanisms of cell recognition and sy napse formation exist in the nervous systems of these two different fa milies of molluscs.