Neuronal expression of catechol O-methyltransferase mRNA in neonatal rat suprachiasmatic nucleus.
We examined the expression profile of catechol O-methyltransferase (COMT) mRNA and its protein in the neonatal rat hypothalamus by in situ hybridization and immunohistochemistry to clarify the sites of dopamine degradation. Strong COMT mRNA expression was observed in the suprachiasmatic nucleus (SCN) throughout its rostrocaudal extent at postnatal day 1 (P1) and P2, and the mRNA levels decreased gradually until P16. COMT mRNA was predominantly localized to the ventral and medial parts of the SCN. Intense COMT immunoreactivity was demonstrated in the ventral SCN and was detected in neuronal perikarya and processes at P1. Ependymal and microglial cells also exhibited strong COMT immunoreactivity. These results indicate that COMT may directly be involved in dopaminergic signaling in the neonatal SCN.
Shirakawa
Tetsuo
T
Center for Advanced Oral Medicine, Hokkaido University Hospital, N13W6 kita-ku, Sapporo, 060-8586 Japan. tshira@den.hokudai.ac.jp
Abe
Michiko
M
Oshima
Shohei
S
Mitome
Masato
M
Oguchi
Haruhisa
H
D000818:Animals; D000831:Animals, Newborn; D002394:Catechol O-Methyltransferase / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics; D002940:Circadian Rhythm / Q000235:genetics*; D004298:Dopamine / Q000378:metabolism*; D004805:Ependyma / Q000166:cytology / Q000201:enzymology / Q000254:growth & development; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D017628:Microglia / Q000166:cytology / Q000201:enzymology; D009474:Neurons / Q000166:cytology / Q000201:enzymology*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013493:Suprachiasmatic Nucleus / Q000166:cytology / Q000201:enzymology* / Q000254:growth & development; D015854:Up-Regulation / Q000235:genetics
D012333:RNA, Messenger; D002394:Catechol O-Methyltransferase; D004298:Dopamine