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Sustained activation of GABAAreceptors in the suprachiasmatic nucleus mediates light-induced phase delays of the circadian clock: a novel function of ionotropic receptors
- Source :
- European Journal of Neuroscience. 42:1830-1838
- Publication Year :
- 2015
- Publisher :
- Wiley, 2015.
-
Abstract
- The suprachiasmatic nucleus (SCN) contains a circadian clock that generates endogenous rhythmicity and entrains that rhythmicity with the day-night cycle. The neurochemical events that transduce photic input within the SCN and mediate entrainment by resetting the molecular clock have yet to be defined. Because GABA is contained in nearly all SCN neurons we tested the hypothesis that GABA serves as this signal in studies employing Syrian hamsters (Mesocricetus auratus). Activation of GABAA receptors was found to be necessary and sufficient for light to induce phase delays of the clock. Remarkably, the sustained activation of GABAA receptors for more than three consecutive hours was necessary to phase delay the clock. The duration of GABAA receptor activation required to induce phase delays would not have been predicted by either the prevalent theory of circadian entrainment or by expectations regarding the duration of ionotropic receptor activation necessary to produce functional responses. Taken together, these data identify a novel neurochemical mechanism essential for phase delaying the “master” circadian clock within the SCN as well as identifying an unprecedented action of an amino acid neurotransmitter involving the sustained activation of ionotropic receptors.
- Subjects :
- Male
Time Factors
Light
Microinjections
GABA Agents
Circadian clock
Biology
Bicuculline
Article
chemistry.chemical_compound
Circadian Clocks
Cricetinae
Reaction Time
medicine
Animals
Circadian rhythm
Dose-Response Relationship, Drug
Mesocricetus
Muscimol
Suprachiasmatic nucleus
GABAA receptor
General Neuroscience
Receptors, GABA-A
nervous system
chemistry
Light effects on circadian rhythm
Suprachiasmatic Nucleus
sense organs
Neuroscience
Ionotropic effect
medicine.drug
Subjects
Details
- ISSN :
- 0953816X
- Volume :
- 42
- Database :
- OpenAIRE
- Journal :
- European Journal of Neuroscience
- Accession number :
- edsair.doi.dedup.....8e4a8ae2dde0cf358412b748cb00198d