Neuropeptide Y phase advances the in vitro hamster circadian clock during the subjective day with no effect on phase during the subjective night

2000 ◽  
Vol 78 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Mary E Harrington ◽  
Kathryn M Schak
Keyword(s):  
Circadian Clock ◽  
Neuropeptide Y ◽  
Firing Rate ◽  
Phase Shifts ◽  
Suprachiasmatic Nuclei ◽  
Subjective Night ◽  
Circadian Change ◽  
Brain Slice Preparation ◽  
Spontaneous Firing Rate

The mammalian daily (circadian) clock is located in the suprachiasmatic nuclei of the hypothalamus. Clock function can be detected by the measurement of the circadian change in spontaneous firing rate of suprachiasmatic nuclei cells in a brain slice preparation in vitro. We investigated the effects of neuropeptide Y on this rhythm of firing rate in hamster suprachiasmatic nuclei neurons. Slices were prepared using standard techniques. On the 1st day in vitro, neuropeptide Y (200 ng/200 nL; 47 pmol) was applied as a microdrop to the suprachiasmatic nuclei region at various times. Spontaneous single-unit firing was measured for 6-12 h on the 2nd day in vitro. Peak firing rate in treated slices was compared with that of untreated control slices to measure phase shifts induced by the peptide. Neuropeptide Y induced phase advances of circa-3h when applied during the subjective day (ZT 2-10) but did not significantly alter phase when applied during the subjective night. The phase shifts to neuropeptide Y in the hamster tissue in vitro are similar in phase dependency and magnitude to shifts measured in vivo.Key words: circadian, neuropeptide Y, rhythm, suprachiasmatic.

scholarly journals cGMP induces phase shifts of a mammalian circadian pacemaker at night, in antiphase to cAMP effects

1989 ◽  
Vol 86 (17) ◽  
pp. 6812-6815 ◽  
Author(s):  
R A Prosser ◽  
A J McArthur ◽  
M U Gillette
Keyword(s):  
Circadian Clock ◽  
Brain Slices ◽  
Phase Shifts ◽  
Suprachiasmatic Nuclei ◽  
Daily Cycle ◽  
Subjective Night ◽  
Camp And Cgmp ◽  
Diurnal Period ◽  
Nocturnal Period

The suprachiasmatic nuclei (SCN) of mammals contain a circadian clock that synchronizes behavioral and physiological rhythms to the daily cycle of light and darkness. We have been probing the biochemical substrates of this endogenous pacemaker by examining the ability of treatments affecting cyclic nucleotide-dependent pathways to induce changes in the phase of oscillation in electrical activity of rat SCN isolated in brain slices. Our previous work has shown that daytime treatments that stimulate cAMP-dependent pathways induce phase shifts of the SCN pacemaker in vitro but treatments during the subjective night are without effect. In this study we report that the phase of SCN oscillation is reset by treatments that stimulate cGMP-dependent pathways, but only during the subjective night. Thus, the nocturnal period of SCN sensitivity to cGMP is in antiphase to the diurnal period of sensitivity to cAMP. These results suggest that cAMP and cGMP affect the SCN pacemaker through separate biochemical pathways intrinsic to the SCN. These studies provide evidence that changing biochemical substrates within the SCN circadian clock may underlie some aspects of differential temporal sensitivity of mammals to resetting stimuli.

Neuropeptide Y blocks serotonergic phase shifts of the suprachiasmatic circadian clock in vitro

1998 ◽  
Vol 808 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Rebecca A Prosser
Keyword(s):  
Circadian Clock ◽  
Neuropeptide Y ◽  
Phase Shifts

Neuropeptide Y blocks GABAB-induced phase-shifts of the suprachiasmatic circadian clock in vitro

1999 ◽  
Vol 821 (2) ◽  
pp. 461-466 ◽  
Author(s):  
Kevin R Biggs ◽  
Rebecca A Prosser
Keyword(s):  
Circadian Clock ◽  
Neuropeptide Y ◽  
Phase Shifts

Neuropeptide Y phase shifts the circadian clock in vitro via a Y2 receptor

Neuroreport ◽  
1996 ◽  
Vol 7 (7) ◽  
pp. 1315-1319 ◽  
Author(s):  
Diego A. Golombek ◽  
Stephany M. Biello ◽  
Regina A. Rendon ◽  
Mary E. Harrington
Keyword(s):  
Circadian Clock ◽  
Neuropeptide Y ◽  
Phase Shifts ◽  
Y2 Receptor

A serotonin agonist phase-shifts the circadian clock in the suprachiasmatic nuclei in vitro

1990 ◽  
Vol 534 (1-2) ◽  
pp. 336-339 ◽  
Author(s):  
Rebecca A. Prosser ◽  
Joseph D. Miller ◽  
H. Craig Heller
Keyword(s):  
Circadian Clock ◽  
Phase Shifts ◽  
Suprachiasmatic Nuclei ◽  
Serotonin Agonist

scholarly journals General Anaesthesia Shifts the Murine Circadian Clock in a Time-Dependant Fashion

2021 ◽  
Vol 3 (1) ◽  
pp. 87-97
Author(s):  
Nicola M. Ludin ◽  
Alma Orts-Sebastian ◽  
James F. Cheeseman ◽  
Janelle Chong ◽  
Alan F. Merry ◽  
...  
Keyword(s):  
Circadian Clock ◽  
General Anaesthesia ◽  
Wheel Running ◽  
Phase Shifts ◽  
Time Dependent ◽  
Suprachiasmatic Nuclei ◽  
Response Curves ◽  
Inhalational Anaesthetic ◽  
Locomotor Rhythms ◽  
Time Dependent Analysis

Following general anaesthesia (GA), patients frequently experience sleep disruption and fatigue, which has been hypothesized to result at least in part by GA affecting the circadian clock. Here, we provide the first comprehensive time-dependent analysis of the effects of the commonly administered inhalational anaesthetic, isoflurane, on the murine circadian clock, by analysing its effects on (a) behavioural locomotor rhythms and (b) PER2::LUC expression in the suprachiasmatic nuclei (SCN) of the mouse brain. Behavioural phase shifts elicited by exposure of mice (n = 80) to six hours of GA (2% isoflurane) were determined by recording wheel-running rhythms in constant conditions (DD). Phase shifts in PER2::LUC expression were determined by recording bioluminescence in organotypic SCN slices (n = 38) prior to and following GA exposure (2% isoflurane). Full phase response curves for the effects of GA on behaviour and PER2::LUC rhythms were constructed, which show that the effects of GA are highly time-dependent. Shifts in SCN PER2 expression were much larger than those of behaviour (c. 0.7 h behaviour vs. 7.5 h PER2::LUC). We discuss the implications of this work for understanding how GA affects the clock, and how it may inform the development of chronotherapeutic strategies to reduce GA-induced phase-shifting in patients.

Neuropeptide Y and glutamate block each other's phase shifts in the suprachiasmatic nucleus in vitro

Neuroscience ◽  
1997 ◽  
Vol 77 (4) ◽  
pp. 1049-1057 ◽  
Author(s):  
S.M Biello ◽  
D.A Golombek ◽  
M.E Harrington
Keyword(s):  
Neuropeptide Y ◽  
Suprachiasmatic Nucleus ◽  
Phase Shifts

Serotonin phase-shifts the mouse suprachiasmatic circadian clock in vitro

2003 ◽  
Vol 966 (1) ◽  
pp. 110-115 ◽  
Author(s):  
Rebecca A Prosser
Keyword(s):  
Circadian Clock ◽  
Phase Shifts

Opposing actions of neuropeptide Y and light on the expression of circadian clock genes in the mouse suprachiasmatic nuclei

2002 ◽  
Vol 15 (1) ◽  
pp. 216-220 ◽  
Author(s):  
Elizabeth S. Maywood ◽  
Hitoshi Okamura ◽  
Michael H. Hastings
Keyword(s):  
Circadian Clock ◽  
Neuropeptide Y ◽  
Clock Genes ◽  
Suprachiasmatic Nuclei ◽  
Circadian Clock Genes
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