Meeting Abstract
As in vertebrates, the heart of gastropod mollusks is myogenic with neuromodulation from the central nervous system. In the pond snail Lymnaea stagnalis the primary source of neuromodulation is by way of the intestinal nerve. Earlier explorations of the central nervous system have identified several populations of neurons that have recognizable modulatory effects on heart rate and cardiac muscle contraction, but it is not certain that all of the relevant neurons have been identified. To address this, I have carried out backfills of the intestinal nerve using using biocytin, which yields backfills of superior quality. The results indicate a much larger and more widespread innervation of the heart than has been previously described. A portion of the newly observed neurons may be sensory, while others may have motor effects. The results will be compared to previous results and the identity of possible transmitters will be explored by double-labeling using transmitter-specific antibodies.
