Tetrodotoxin-sensitivity of nicotine-evoked dopamine release from rat striatum

Neuropharmacology. 1996;35(11):1531-6. doi: 10.1016/s0028-3908(96)00117-7.


Recent observations from synaptosome preparations have questioned the tetrodotoxin (TTX) insensitivity of nicotine-evoked release in the striatum, a characteristic previously considered diagnostic of presynaptically located nicotinic acetylcholine receptors (nAChRs). Therefore, we have undertaken a comparison of nicotine-evoked dopamine release in the presence of TTX from the rat striatum in vitro, using synaptosomes and brain slices, and in vivo, using microdialysis. In P2 and Percoll-purified synaptosome preparations, 1.5 microM TTX partially inhibited nicotine-evoked [3H]dopamine release by 54% and 37%, respectively, whereas in more intact preparations (brain slices and microdialysis) TTX completely inhibited mecamylamine-sensitive nicotine-stimulated dopamine release. These results suggest that caution should be exercised in the interpretation of TTX sensitivity of nicotine-evoked responses with regard to the location of nAChRs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cholinergic Agents / pharmacology*
  • Dopamine / metabolism*
  • Extracellular Space / drug effects
  • Extracellular Space / metabolism
  • In Vitro Techniques
  • Male
  • Mecamylamine / pharmacology
  • Microdialysis
  • Neostriatum / drug effects
  • Neostriatum / metabolism*
  • Nicotine / pharmacology*
  • Nicotinic Agonists / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Synaptosomes / drug effects
  • Synaptosomes / metabolism
  • Tetrodotoxin / pharmacology*


  • Cholinergic Agents
  • Nicotinic Agonists
  • Tetrodotoxin
  • Mecamylamine
  • Nicotine
  • Dopamine