A marked diurnal rhythm of melatonin ML1A receptor mRNA expression in the suprachiasmatic nucleus

Brain Res Mol Brain Res. 1997 Oct 3;49(1-2):303-6. doi: 10.1016/s0169-328x(97)00218-0.


Melatonin (ML1A) receptor binding in the suprachiasmatic nucleus (SCN) exhibits a diurnal rhythm, with significant increases during the daytime. In order to determine whether the diurnal variation in binding is reflected by a cycling of melatonin ML1A receptor mRNA levels, we utilized a semiquantitative reverse transcriptase-polymerase chain reaction procedure to examine receptor expression throughout the light-dark cycle. Here we report the first evidence of a significant diurnal variation in ML1A receptor mRNA levels within the SCN. Furthermore, this mRNA expression occurs approximately 3 h prior to, but is tightly correlated to the diurnal rhythm in high-affinity melatonin binding in the SCN.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / biosynthesis
  • Animals
  • Circadian Rhythm*
  • Darkness
  • Gene Expression Regulation*
  • Light
  • Male
  • Melatonin / metabolism
  • Polymerase Chain Reaction
  • RNA, Messenger / biosynthesis
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Cell Surface / biosynthesis*
  • Receptors, Cytoplasmic and Nuclear / biosynthesis*
  • Receptors, Melatonin
  • Suprachiasmatic Nucleus / metabolism*
  • Transcription, Genetic*


  • Actins
  • RNA, Messenger
  • Receptors, Cell Surface
  • Receptors, Cytoplasmic and Nuclear
  • Receptors, Melatonin
  • Melatonin