RT Journal Article SR Electronic T1 Anterograde Signaling by Nitric Oxide: Characterization andIn Vitro Reconstitution of an Identified Nitrergic Synapse JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 5463 OP 5476 DO 10.1523/JNEUROSCI.18-14-05463.1998 VO 18 IS 14 A1 Park, Ji-Ho A1 Straub, Volko A. A1 O’Shea, Michael YR 1998 UL http://www.jneurosci.org/content/18/14/5463.abstract AB Nitric oxide (NO) is recognized as a signaling molecule in the CNS where it is a candidate retrograde neurotransmitter. Here we provide direct evidence that NO mediates slow excitatory anterograde transmission between the NO synthase (NOS)-expressing B2 neuron and an NO-responsive follower neuron named B7nor. Both are motoneurons located in the buccal ganglia of the snail Lymnaea stagnaliswhere they participate in feeding behavior. Transmission between B2 and B7nor is blocked by inhibiting NOS and is suppressed by extracellular scavenging of NO. Furthermore, focal application of NO to the cell body of the B7nor neuron causes a depolarization that mimics the effect of B2 activity. The slow interaction between the B2 and B7nor neurons can be re-established when the two neurons are cocultured, and it shows the same susceptibility to NOS inhibition and NO scavenging. In cell culture we have also examined spatial aspects of NO signaling. We show that before the formation of an anatomical connection, the presynaptic neuron can cause depolarizing potentials in the follower neuron at distances up to 50 μm. The strength of the interaction increases when the distance between the cells is reduced. Our results suggest that NO can function as both a synaptic and a nonsynaptic signaling molecule.