The expression of mRNA for a kappa opioid receptor in the substantia nigra of Parkinson's disease brain

Mitsuhiko Yamada, Karen Groshan, Chan Tran Phung, Misa Yamada, Takashi Hisamitsu, Elliott Richelson

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


We molecularly cloned the kappa opioid receptor from a human substantia nigra cDNA library. When expressed in HEK293 cells, the cloned receptor had similar pharmacological characteristics to the rat kappa opioid receptor. Northern blot analysis showed the presence of a single transcript of about 6 kb in size for mRNA prepared from the substantia nigra. Using in situ hybridization histochemistry, we studied the expression of this receptor in postmortem human brains from control and Parkinson's disease subjects. Kappa opioid receptor mRNA was present in melanized (possibly dopaminergic) neurons of the substantia nigra and the nucleus paranigralis. On the other hand, Parkinson's disease brains had markedly fewer melanized neurons, as expected, and correspondingly very low or background levels of mRNA for the kappa opioid receptor. However, in some cases, remaining melanized neurons still expressed the receptor mRNA. From these results we suggest that dopaminergic neurons in the human substantia nigra and the nucleus paranigralis synthesize kappa opioid receptors and express them in their perikarya and their terminal regions. The kappa opioid receptor expressed in the melanized neurons may play a role in the normal function of dopaminergic systems and possibly in the etiology of Parkinson's disease.

Original languageEnglish (US)
Pages (from-to)12-20
Number of pages9
JournalMolecular Brain Research
Issue number1
StatePublished - Feb 1997


  • Aging
  • Dopamine
  • Human
  • Melanin
  • Molecular cloning
  • Transfection

ASJC Scopus subject areas

  • Molecular Biology
  • Cellular and Molecular Neuroscience


Dive into the research topics of 'The expression of mRNA for a kappa opioid receptor in the substantia nigra of Parkinson's disease brain'. Together they form a unique fingerprint.

Cite this