Nonphotic Entrainment by 5-HT1A/7Receptor Agonists Accompanied by ReducedPer1andPer2mRNA Levels in the Suprachiasmatic Nuclei

ABSTRACT A quantitative analysis of spermatogenesis has been made in rats bearing bilateral lesions of the lateral mammillary nuclei or of the suprachiasmatic nuclei of the hypothalamus. There was no significant change in the germinal cell counts in lesioned rats as compared either with normal or with sham operated rats.

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Faculty Opinions recommendation of The opioid fentanyl affects light input, electrical activity and Per gene expression in the hamster suprachiasmatic nuclei.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.31405.487898 ◽

2006 ◽

Author(s):

Elise Sarton

Keyword(s):

Gene Expression ◽

Electrical Activity ◽

Suprachiasmatic Nuclei ◽

Per Gene ◽

Light Input

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Nonphotic entrainment of the human circadian pacemaker

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1998.274.4.r991 ◽

1998 ◽

Vol 274 (4) ◽

pp. R991-R996 ◽

Cited By ~ 32

Author(s):

Elizabeth B. Klerman ◽

David W. Rimmer ◽

Derk-Jan Dijk ◽

Richard E. Kronauer ◽

Joseph F. Rizzo ◽

...

Keyword(s):

Circadian Rhythms ◽

Light Exposure ◽

Core Body Temperature ◽

Biological Clock ◽

Bright Light ◽

Circadian Pacemaker ◽

Temperature Rhythms ◽

Blind Individuals ◽

Nonphotic Entrainment ◽

Core Body

In organisms as diverse as single-celled algae and humans, light is the primary stimulus mediating entrainment of the circadian biological clock. Reports that some totally blind individuals appear entrained to the 24-h day have suggested that nonphotic stimuli may also be effective circadian synchronizers in humans, although the nonphotic stimuli are probably comparatively weak synchronizers, because the circadian rhythms of many totally blind individuals “free run” even when they maintain a 24-h activity-rest schedule. To investigate entrainment by nonphotic synchronizers, we studied the endogenous circadian melatonin and core body temperature rhythms of 15 totally blind subjects who lacked conscious light perception and exhibited no suppression of plasma melatonin in response to ocular bright-light exposure. Nine of these fifteen blind individuals were able to maintain synchronization to the 24-h day, albeit often at an atypical phase angle of entrainment. Nonphotic stimuli also synchronized the endogenous circadian rhythms of a totally blind individual to a non-24-h schedule while living in constant near darkness. We conclude that nonphotic stimuli can entrain the human circadian pacemaker in some individuals lacking ocular circadian photoreception.

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In Syrian and European hamsters, the duration of sensitive phase to light of the suprachiasmatic nuclei depends on the photoperiod

Neuroscience Letters ◽

10.1016/0304-3940(96)12535-0 ◽

1996 ◽

Vol 208 (1) ◽

pp. 37-40 ◽

Cited By ~ 51

Author(s):

Patrick Vuillez ◽

Nathalie Jacob ◽

Rebecca Teclemariam-Mesbah ◽

Paul Pévet

Keyword(s):

Suprachiasmatic Nuclei ◽

Sensitive Phase

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

Clocks & Sleep ◽

10.3390/clockssleep3010006 ◽

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.

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