MOLECULAR CHARACTERIZATION OF NOS IN A MOLLUSK - EXPRESSION IN A GIANT MODULATORY NEURON

Here we report on the molecular characterization of the first mollusca n NOS in the CNS of the pond snail Lymnaea stagnalis. This Lymnaea NOS (Lym-nNOS) which is expressed preferentially in the CNS is most simil ar to mammalian neuronal NOS but contains tandem repeats of a seven am ino acid motif not found in any other known NOS. We have localized Lym -nNOS to the serotonergic cerebral giant cells (CGCs) which modulate s ynaptic transmission within a neural network that generates feeding be havior. Our results suggest that the CGCs employ both NO and serotonin in the modulation of the central neural network underlying feeding. ( C) 1998 John Wiley & Sons, Inc.