In vivo calcium imaging of OFF-responding ASK chemosensory neurons in C. elegans
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Background: How neurons and neuronal circuits transform sensory input into behavior is not wellunderstood. Because of its well-described, simple nervous system, Caenorhabditis elegans is an ideal modelorganism to study this issue. Transformation of sensory signals into neural activity is a crucial first step in thesensory–motor transformation pathway in an animal's nervous system. We examined the properties ofchemosensory ASK neurons of C. elegans during sensory stimulation.Method: A genetically encoded calcium sensor protein, G-CaMP, was expressed in ASK neurons of C. elegans,and the intracellular calcium dynamics of the neurons were observed.Results: After application of the attractants L-lysine or food-related stimuli, the level of calcium in ASKneurons decreased. In contrast, responses increased upon stimulus removal. Opposite responses wereobserved after application and removal of a repellent.Conclusion: The observed changes in response to external stimuli suggest that the activity of ASK neuronsmay impact stimulus-evoked worm behavior. The stimulus-ON/activity-OFF properties of ASK neurons aresimilar to those of vertebrate retinal photoreceptors.General significance: Analysis of sensory–motor transformation pathways based on the activity and structureof neuronal circuits is an important goal in neurobiology and is practical in C. elegans. Our study providesinsights into the mechanism of such transformation in the animal.
- Biochimica et Biophysica Acta (BBA) - General Subjects
Biochimica et Biophysica Acta (BBA) - General Subjects 1790(8), 765-769, 2009-01-01