Suprachiasmatic circadian pacemaker of rat shows two windows of sensitivity to neuropeptide Y in vitro

Medanic, M.; Gillette, Martha U.

doi:10.1016/0006-8993(93)90166-k

Cited by 59 publications

(44 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Neuropeptide Y and ␥-aminobutyric acid (GABA) are putative transmitters of non-photic signals via the geniculohypothalamic tract to the SCN (77)(78)(79)(80)(81)(82)(83)(84)(85)(86)(87)(88)(89)(90)(91). We observed C-flanking peptide of neuropeptide Y, which was reported in geniculohypothalamic tract projections to the SCN (82), and the peptide fragment of GABA receptor subunit ␣-6.…”

Section: Discussionmentioning

confidence: 81%

Endogenous Peptide Discovery of the Rat Circadian Clock

Lee

Atkins

Hatcher

et al. 2010

Molecular & Cellular Proteomics

Self Cite

View full text Add to dashboard Cite

Understanding how a small brain region, the suprachiasmatic nucleus (SCN), can synchronize the body's circadian rhythms is an ongoing research area. This important time-keeping system requires a complex suite of peptide hormones and transmitters that remain incompletely characterized. Here, capillary liquid chromatography and FTMS have been coupled with tailored software for the analysis of endogenous peptides present in the SCN of the rat brain. After ex vivo processing of brain slices, peptide extraction, identification, and characterization from tandem FTMS data with <5-ppm mass accuracy produced a hyperconfident list of 102 endogenous peptides, including 33 previously unidentified peptides, and 12 peptides that were post-translationally modified with amidation, phosphorylation, pyroglutamylation, or acetylation. This characterization of endogenous peptides from the SCN will aid in understanding the molecular mechanisms that mediate rhythmic behaviors in mammals. Molecular & Cellular Proteomics 9:285-297, 2010.

show abstract

Section: Discussionmentioning

confidence: 81%

Endogenous Peptide Discovery of the Rat Circadian Clock

Lee

Atkins

Hatcher

et al. 2010

Molecular & Cellular Proteomics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Phase advances were also induced at CT 10 by 2-[125I]-iodomelatonin [23]. However, application of other neurochemicals [ 11 ], including serotonin [25], neuropeptide Y [26] and glutamate [4], at this time did not induce the same pattern of phase shifts as melatonin. The melatonin-sensitive periods appear to bracket the transition points in the entrained lighting cycle.…”

Section: Circadian Changes In the Sensitivity Of Scn Rhythms To Phasementioning

confidence: 99%

Circadian actions of melatonin at the suprachiasmatic nucleus

Gillette

McArthur

1995

Behavioural Brain Research

Self Cite

109

View full text Add to dashboard Cite

The biological clock in the suprachiasmatic nucleus (SCN) of the hypothalamus plays a well-defined role in regulating melatonin production by the pineal. Emerging evidence indicates that melatonin itself can feed back upon the SCN and thereby influence circadian functions. Melatonin administration has been shown to entrain activity rhythms in rodents and humans. Melatonin binds specifically within the SCN and alters SCN physiology by both acute and clock-resetting mechanisms. The circadian clock in the SCN appears to temporally restrict its own sensitivity to melatonin, such that physiological sensitivity is greatest in the subjective dusk period

show abstract

“…Lesions of the hamster geniculohypothalamic tract block nonphotic phase shifts (Johnson et al, 1988;Biello et al, 1991;Meyer et al, 1993;Janik and Mrosovsky, 1994). NPY can induce nonphotic-type phase shifts in rats and hamsters in vivo (Albers and Ferris, 1984;Huhman and Albers, 1994;Biello and Mrosovsky, 1996) and in vitro (Shibata and Moore, 1993;Golombek et al, 1996;Biello et al, 1997; but see Medanic and Gillette, 1993). Infusion of antiserum to NPY into the area of the hamster SCN blocks phase shifts to induced activity (Biello et al, 1994).…”

mentioning

confidence: 99%

Circadian Phase Shifts to Neuropeptide YIn Vitro: Cellular Communication and Signal Transduction

et al. 1997

View full text Add to dashboard Cite

Mammalian circadian rhythms originate in the hypothalamic suprachiasmatic nuclei (SCN), from which rhythmic neural activity can be recorded in vitro. Application of neurochemicals can reset this rhythm. Here we determine cellular correlates of the phase-shifting properties of neuropeptide Y (NPY) on the hamster circadian clock in vitro. Drug or control treatments were applied to hypothalamic slices containing the SCN on the first day in vitro. The firing rates of individual cells were sampled on the second day in vitro. Control slices exhibited a peak in firing rate in the middle of the day. Microdrop application of NPY to the SCN phase advanced the time of peak firing rate. This phase-shifting effect of NPY was not altered by block of sodium channels with tetrodotoxin or block of calcium channels with cadmium and nickel, consistent with a direct postsynaptic site of action. Pretreatment with the glutamate receptor antagonists (DL-2-amino-5-phosphonovaleric acid and 6-cyano-7-nitroquinoxaline-2,3-dione disodium) also did not alter phase shifts to NPY. Blocking GABA A receptors with bicuculline (Bic) had effects only at very high (millimolar) doses of Bic, whereas blocking GABA B receptors did not alter effects of NPY. Phase shifts to NPY were blocked by pretreatment with inhibitors of protein kinase C (PKC), suggesting that PKC activation may be necessary for these effects. Bathing the slice in low Ca 2ϩ /high Mg 2ϩ can block phase shifts to NPY, possibly via a depolarizing action. A depolarizing high K ϩ bath can also block NPY phase shifts. The results are consistent with direct action of NPY on pacemaker neurons, mediated through a signal transduction pathway that depends on activation of PKC.

show abstract

Suprachiasmatic circadian pacemaker of rat shows two windows of sensitivity to neuropeptide Y in vitro

Cited by 59 publications

References 51 publications

Endogenous Peptide Discovery of the Rat Circadian Clock

Endogenous Peptide Discovery of the Rat Circadian Clock

Circadian actions of melatonin at the suprachiasmatic nucleus

Circadian Phase Shifts to Neuropeptide YIn Vitro: Cellular Communication and Signal Transduction

Contact Info

Product

Resources

About