A neuronal network from the mollusc Lymnaea stagnalis.
The morphology, electrophysiology, and synaptic inputs of a ventrally located neuronal network from the CNS of the pond snail Lymnaea stagnalis was investigated. Three large, previously identified neurons [55] known as right parietal ventral one, two, and three (RPV1,2,&3) were found to be electrically coupled to one another. Coupling between either RPV1&2 or RPV1&3 was weak while coupling between RPV2&3 was strong. Consistent bursting activity was observed in neuron RPV1 while neurons RPV2&3 were either silent or fired tonically. When isolated in vitro, similar patterns of activity could be elicited in neurons RPV1-3. Lucifer yellow staining revealed that these cells send axons through nerves innervating musculature involved in locomotion, whole-body withdrawal, and cardio-respiratory function. Neurons RPV1-3 were found to be inhibited by an identified interneuron, visceral dorsal four, known to be directly involved in cardio-respiratory behavior [43]. Furthermore, neurons RPV1-3 were also inhibited by a wide-acting synaptic input, known as Input three [9], which is associated with respiratory pattern generation [43]. An interneuron, identified as right pedal dorsal eleven (RPeD11), which coordinates locomotory and withdrawal behavior [44], was found to excite neuron RPV1. When neurons RPeD11 and RPV1 were isolated in vitro and allowed to extend neurites, they formed a synaptic connection similar to that observed in the isolated brain. In vitro work on these neurons may make them an attractive model to study synapse formation and bursting activity.
Magoski
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NS
Department of Anatomy, Faculty of Medicine, University of Calgary, Alta., Canada.
Syed
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NI
Bulloch
A G
AG
D000818:Animals; D002478:Cells, Cultured; D004594:Electrophysiology; D005456:Fluorescent Dyes; D006329:Heart Conduction System / Q000166:cytology / Q000502:physiology; D007395:Interneurons / Q000502:physiology; D007546:Isoquinolines; D008195:Lymnaea / Q000033:anatomy & histology* / Q000502:physiology*; D009415:Nerve Net / Q000033:anatomy & histology* / Q000166:cytology / Q000502:physiology*; D009433:Neural Inhibition; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure*; D012143:Respiratory Physiological Phenomena; D012137:Respiratory System / Q000166:cytology; D013569:Synapses / Q000502:physiology
D005456:Fluorescent Dyes; D007546:Isoquinolines; C017475:lucifer yellow