title: A marked diurnal rhythm of melatonin ML1A receptor mRNA expression in the suprachiasmatic nucleus.
abstract: 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.
authors.affiliation: Department of Biomedical Sciences, McMaster University Health Science Centre, Hamilton, Ontario, Canada.
authors.forename: J M
authors.initials: JM
authors.lastname: Neu
authors.forename: L P
authors.initials: LP
authors.lastname: Niles
mesh_terms: D000199:Actins / Q000096:biosynthesis; D000818:Animals; D002940:Circadian Rhythm; D003624:Darkness; D005786:Gene Expression Regulation; D008027:Light; D008297:Male; D008550:Melatonin / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011956:Receptors, Cell Surface / Q000096:biosynthesis*; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis*; D044094:Receptors, Melatonin; D013493:Suprachiasmatic Nucleus / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D000199:Actins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D044094:Receptors, Melatonin; D008550:Melatonin