The importance of cnidarian synapses for neurobiology

Despite being the most primitive organisms to possess a nervous system, cnidarians afford rare opportunities for studying various, general aspects of chemical synaptic transmission. This is made possible by the unique organization of their nervous systems and by the fact that in certain species the neurons and synapses are readily accessible for intracellular recordings and voltage clamp. The results obtained from such studies are summarized here, with particular emphasis on work with two species, Cyanea capillata (Scyphozoa) and Polyorchis pennicilatus (Hydrozoa). The potential of these preparations for providing additional data is also discussed.