Tetrodotoxin-resistant impulses in single nociceptor nerve terminals in guinea-pig cornea
Article first published online: 22 SEP 2004
The Journal of Physiology
Volume 512, Issue 1, pages 211–217, October 1998
How to Cite
Brock, J. A., McLachlan, E. M. and Belmonte, C. (1998), Tetrodotoxin-resistant impulses in single nociceptor nerve terminals in guinea-pig cornea. The Journal of Physiology, 512: 211–217. doi: 10.1111/j.1469-7793.1998.211bf.x
- Issue published online: 22 SEP 2004
- Article first published online: 22 SEP 2004
- (Received 9 June 1998; accepted after revision 27 July 1998)
- 1Extracellular recording techniques have been used to study nerve impulses in single sensory nerve terminals in guinea-pig cornea isolated in vitro.
- 2Nerve impulses occurred spontaneously and were evoked by electrical stimulation of the ciliary nerves.
- 3The nerve impulses were identified as originating in polymodal receptors, mechano-receptors or ‘cold’ receptors. All three types are believed to be nociceptors.
- 4Tetrodotoxin (TTX, 1 μm) blocked nerve impulses evoked by electrical stimulation of the ciliary nerves. However, ongoing and/or naturally evoked nerve impulses persisted in the presence of TTX in all three types of receptors. Lignocaine (lidocaine; 1 mm) blocked all electrical activity.
- 5TTX-resistant sodium channels therefore play a major role in generating the action potentials that signal pain to the brain.