Chemesthesis in the Earthworm, Lumbricus terrestris: The search for TRP Channels

Chemesthesis is the chemical stimulation of receptors on somatosensory neurons usually by noxious chemicals leading to irritation. Transient receptor potential channels play a major role in detecting chemesthetic stimuli and are found in a wide variety of organisms, from yeast to humans. Currently, there are no reports of TRP channels in earthworms. Earthworms, including Lumbricus terrestris, aerate and enrich soil providing a suitable habitat for plants. Hence, chemicals in the soil which repel earthworms could have deleterious effects on plant growth. Allyl isothiocyanate, a prototypical TRPA1 agonist, has been used as an expellant for sampling earthworms, suggesting that earthworms possess TRPA1 channels. We began the search for TRPA1-like channels in earthworms using electrophysiological, immunohistochemical, behavioral and cell dissociation/calcium imaging techniques. We obtained responses from segmental nerves to tactile stimulus, 50mM AITC and pH 3.8, 4.0 and 4.2. Some cells in the epidermis displayed positive immunoreactivity for Drosophila and human TRPA1 homologs. L. terrestris detected and avoided ATIC and cinnamaldehyde (another TRPAI agonist) but not capsaicin (a TRPV1 agonist) in air and soil T-maze behavioral assays. We were able to dissociate cells from L. terrestris epithelium and ventral nerve cord, but could not use them in calcium-imaging experiments.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2016

Author dc:creator

• Kim, Albert Hue-Soo

• Chemesthesis

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10339/59268

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/59268