Meeting Abstract

3.6  Jan. 4  Peripheral sensory pathways in the pond snail Lymnaea stagnalis WYETH, R.C.*; CROLL, R.P.; Dalhousie University Russell.Wyeth@dal.ca

Sensory systems are integral to the neural control of behavior. However, despite extensive neuroethological study of gastropod molluscs, there is only patchy understanding of their sensory pathways. For example, previous work has identified nitrergic chemosensory neurons, glutamatergic mechanosensory neurons, and an extensive population of catecholaminergic sensory neurons of unknown modality. Other observations suggest a histaminergic sensory innervation may be present, and peptidergic sensory neurons have been identified in some species. However, these observations are collated from different species and different studies. There has been no comprehensive study in a single species of all transmitters in both peripheral and central locations, making it difficult to match modality, morphology and neurotransmitter content. Consequently, our goal is to create a thorough map of the sensory neuroanatomy of the gastropod Lymnaea stagnalis. Using a combination of backfills, vital stains, and immunocytochemistry, we are cataloguing the different components of the nervous system in the lips and tentacles and their connections to the central nervous system. In addition to confirming the existence of previously identified nervous system components, we have found previously undescribed peripheral sensory neurons that we hypothesize are mechanosensory. In further physiological experiments, we plan to identify the different modalities of these and other populations identified in the map. When finished, the sensory map will provide a basis for targeted studies of sensory contributions to the neural control of specific gastropod behaviours. Furthermore, these results will improve our understanding of both mechanosensation and the peripheral nervous system, both neglected areas of study in gastropods.