Let there be 'more' light: enhancement of light actions on the circadian system through non-photic pathways
Autor: | Mary E. Harrington, Paola C. Yannielli |
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Rok vydání: | 2004 |
Předmět: |
Models
Molecular Serotonin animal structures Light genetic structures Photic Stimulation Cell Cycle Proteins Biology Serotonergic Models Biological Animals Neuropeptide Y Circadian rhythm Lighting Phase response curve Suprachiasmatic nucleus General Neuroscience Nuclear Proteins Period Circadian Proteins Neuropeptide Y receptor Circadian Rhythm Light effects on circadian rhythm Suprachiasmatic Nucleus sense organs Neuroscience Transcription Factors |
Zdroj: | Progress in Neurobiology. 74:59-76 |
ISSN: | 0301-0082 |
Popis: | Circadian rhythms are internally generated circa 24 h rhythms. The phase of the circadian pacemaker in mammals can be adjusted by external stimuli such as the daily cycle of light, as well as by internal stimuli such as information related to the physiological and behavioral status of the organism, collectively called "non-photic stimuli". We review a large number of studies regarding photic-non-photic interactions on the circadian system, with special focus on two widely described neurotransmitters associated with non-photic input pathways: neuropeptide Y (NPY) and serotonin 5-HT. Both neurotransmitters are capable of phase advancing the master pacemaker oscillation when applied during the subjective day, as do several behavioral manipulations. Also, both are capable of inhibiting light-induced phase shifts during the subjective night, suggesting a dynamic interaction between photic and non-photic stimuli in the fine-tuning of the pacemaker function. Suppression of the NPYergic and/or serotonergic non-photic input pathways can in turn potentiate the phase-shifting effects of light. These findings pose new questions about the possibility of a physiological role for the dynamic interaction between photic and non-photic inputs. This might be particularly important in the case of circadian system adjustments under certain conditions, such as depression, shift work or jet lag. |
Databáze: | OpenAIRE |
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