Neuropeptide Y rapidly reduces Period 1 and Period 2 mRNA levels in the hamster suprachiasmatic nucleus.
The mammalian suprachiasmatic nucleus (SCN) contains the main circadian clock. Neuropeptide Y (NPY) that is released from the intergeniculate leaflet of the lateral geniculate body to the SCN, acts in the SCN to advance circadian phase in the subjective day via the NPY Y2 receptor. We used semi-quantitative in situ hybridization to determine the effect of NPY on circadian clock genes, Period 1 (Per1) and Period 2 (Per2), expression in SCN slices. Addition of NPY to the brain slices in the subjective day resulted in reduction of Per1 and Per2 mRNA levels 0.5 and 2 h after treatment. NPY Y1/Y5 and Y2 agonists decreased Per1 within 0.5 h. These results suggest that NPY may induce phase shifts by mechanisms involving or resulting in reduction of Per1 and Per2 mRNA levels.
Fukuhara
C
C
Neuroscience Institute, Morehouse School of Medicine, 720 Westview Drive, SW, Atlanta, GA 30310-1495, USA. fukuhac@msm.edu
Brewer
J M
JM
Dirden
J C
JC
Bittman
E L
EL
Tosini
G
G
Harrington
M E
ME
D000818:Animals; D001683:Biological Clocks / Q000187:drug effects / Q000502:physiology; D018797:Cell Cycle Proteins; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology*; D006224:Cricetinae; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D017403:In Situ Hybridization; D008297:Male; D008647:Mesocricetus; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009478:Neuropeptide Y / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology; D009687:Nuclear Proteins / Q000235:genetics*; D010446:Peptide Fragments / Q000494:pharmacology; D056950:Period Circadian Proteins; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism*; D017476:Receptors, Neuropeptide Y / Q000187:drug effects / Q000378:metabolism; D013493:Suprachiasmatic Nucleus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors; D014157:Transcription Factors
D018797:Cell Cycle Proteins; D009478:Neuropeptide Y; D009687:Nuclear Proteins; D010446:Peptide Fragments; C513312:Per2 protein, mouse; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D017476:Receptors, Neuropeptide Y; D014157:Transcription Factors; C113547:neuropeptide Y (3-36); C062259:neuropeptide Y, Leu(31)-Pro(34)-