Action potential initiation in the peripheral terminals of cold-sensitive neurones innervating the guinea-pig cornea
Richard W Carr, Svetlana Pianova, David D McKemy, James A Brock
JOURNAL OF PHYSIOLOGY-LONDON | WILEY-BLACKWELL PUBLISHING, INC | Published : 2009
The site at which action potentials initiate within the terminal region of unmyelinated sensory axons has not been resolved. Combining recordings of nerve terminal impulses (NTIs) and collision analysis, the site of action potential initiation in guinea-pig corneal cold receptors was determined. For most receptors (77%), initiation mapped to a point in the time domain that was closer to the nerve terminal than to the site of electrical stimulation at the back of the eye. Guinea-pig corneal cold receptors are Adelta-neurones that lose their myelin sheath at the point where they enter the cornea, and therefore their axons conduct more slowly within the cornea. Allowing for this inhomogeneity i..View full abstract
Awarded by NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE
We are very grateful to Swetlana Nikolajewa, Peter Grafe and James Fallon for valuable discussions. This work was supported by the Australian Research Council.