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GABAergic mechanisms in the suprachiasmatic nucleus that influence circadian rhythm
Author(s) -
Ono Daisuke,
Honma Kenichi,
Honma Sato
Publication year - 2021
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/jnc.15012
Subject(s) - suprachiasmatic nucleus , circadian rhythm , light effects on circadian rhythm , efferent , gabaergic , biology , neuroscience , circadian clock , hypothalamus , inhibitory postsynaptic potential , neurotransmitter , excitatory postsynaptic potential , endocrinology , medicine , central nervous system , afferent
The mammalian central circadian clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN contains multiple circadian oscillators which synchronize with each other via several neurotransmitters. Importantly, an inhibitory neurotransmitter, γ‐amino butyric acid (GABA), is expressed in almost all SCN neurons. In this review, we discuss how GABA influences circadian rhythms in the SCN. Excitatory and inhibitory effects of GABA may depend on intracellular Cl ‐ concentration, in which several factors such as day‐length, time of day, development, and region in the SCN may be involved. GABA also mediates oscillatory coupling of the circadian rhythms in the SCN. Recent genetic approaches reveal that GABA refines circadian output rhythms, but not circadian oscillations in the SCN. Since several efferent projections of the SCN have been suggested, GABA might work downstream of neuronal pathways from the SCN which regulate the temporal order of physiology and behavior.