GABA, the predominant inhibitory neurotransmitter present in the mammalian CNS, is also found in the periphery. GABA actions are mediated by the ionotropic GABA(A)/GABA(C) receptors, as well as the metabotropic GABA(B) receptor. The metabotropic GABA-B receptors are coupled to G proteins and modulate synaptic transmission through intracellular effector systems Goei et al. (1998).
NCBI Summary:
This gene encodes a receptor for gamma-aminobutyric acid (GABA), which is the main inhibitory neurotransmitter in the mammalian central nervous system. This receptor functions as a heterodimer with GABA(B) receptor 2. Defects in this gene may underlie brain disorders such as schizophrenia and epilepsy. Alternative splicing generates multiple transcript variants, but the full-length nature of some of these variants has not been determined. [provided by RefSeq, Jan 2016]
General function
Receptor
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Cellular localization
Plasma membrane
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Ovarian function
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Expression regulated by
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Ovarian localization
Oocyte, Cumulus, Granulosa
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Different transcriptional levels of GABAA receptor subunits in mouse cumulus cells around oocytes at different mature stage.
Gynecol Endocrinol. 2016
PMID: 27345459
By using reverse transcriptase-polymerase chain reaction with a specific set of primers for two isoform of metabotropic GABAB receptor and Southern blot analysis, Castelli et al. 1998 found that both isoforms of the GABA(B) receptor are expressed not only throughout the brain but also in all peripheral organs examined, including ovary and testis.
Schaeffer et al. (1982) demonstrated high affinity (Kd = 15-21 nM), specific GABA binding sites in the rat ovaries by specific 3H-muscimol binding and the majority of GABA binding sites were associated with the granulosa cells. Amenta et al. (1986) studied the distribution of 3H-muscimol within guinea pig ovary using combined radioreceptor binding studies and histoautoradiographic technique. 3H-muscimol was bound by sections of ovary in a manner consistent with the existence of specific GABA receptors. 3H muscimol binding sites were found in the follicle and in the oocytes. The number of oocyte and follicular receptors gradually decreases during the development of ovarian follicles.