Asymmetrically lesioned mesencephalon in healthy rodents: call for caution

Brain Res. 2004 Oct 1;1022(1-2):251-3. doi: 10.1016/j.brainres.2004.07.014.


Stereological counting of tyrosine-hydroxylase immunoreactive (TH-IR) neurons in the mesencephalon is a pivotal parameter in assessing the extent of lesioning in animal models of Parkinson's disease. We here show that the number of TH-IR neurons often appears abnormally decreased in healthy--commercially available--mice and rats, although both the number of Nissl-stained cells and the striatal dopaminergic innervation are unaffected. This potential bias in assessing extent of neurotoxin-induced lesion and subsequent protection by pharmacological manipulation prompts us to call for caution in setting up experimental designs.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Count / methods
  • Disease Models, Animal
  • Immunohistochemistry / methods
  • Male
  • Mesencephalon / injuries
  • Mesencephalon / pathology*
  • Mice
  • Mice, Inbred C57BL
  • Neurons / metabolism*
  • Parkinson Disease / metabolism
  • Parkinson Disease / pathology
  • Probability
  • Rats
  • Rats, Wistar
  • Tyrosine 3-Monooxygenase / metabolism*


  • Tyrosine 3-Monooxygenase