FUNCTIONAL COUPLING OF Gi SUBTYPE WITH GABAB RECEPTOR/ADENYLYL CYCLASE SYSTEM: ANALYSIS USING A RECONSTITUTED SYSTEM WITH PURIFIED GTP-BINDING PROTEIN FROM BOVINE CEREBRAL CORTEX

GABABReceptor Activation Protects Neurons from Apoptosis via IGF-1 Receptor Transactivation

“…Interestingly, we found that this anti-apoptotic effect mediated by GABA B receptor may not require changes in intracellular cAMP levels. Works have shown that GABA B receptor from rat brain membranes can couple to both G o -and G i -proteins, resulting in an inhibition of adenylate cyclase activity and cAMP production, but not to G q and G s (Nishikawa et al, 1997;Odagaki et al, 2000;Odagaki and Koyama, 2001). Previous studies suggested that due to the low expression of G i in comparison to G o , GABA B receptor may be preferentially coupled to G o in neurons (Gierschik et al, 1986).…”

Transient Activation of GABAB Receptors Suppresses SK Channel Currents in Substantia Nigra Pars Compacta Dopaminergic Neurons

“…One of the best described targets of G i/o signaling is adenylyl cyclase (AC) [56,57]. SNc dopaminergic neurons express AC1 isoforms that are stimulated by Ca 2+ (S1 Table), raising the possibility that this form of AC is constitutively active during pacemaking.…”

Ethanol Modulation of γ‐Aminobutyric Acid (GABA)‐Mediated Inhibition of Cerebellar Purkinje Neurons: Relationship to GABAb Receptor Input

“…The GABA B receptor is a G-protein-coupled metabotropic receptor (Andrade et al, 1986;Sodickson and Bean, 1996), but GABA B agonists alone, unlike ␤-adrenergic agonists, seem to have little effect on cAMP formation. On the other hand, GABA B receptors can be coupled to inhibition as well as enhancement of adenylyl cyclase activation (Bowery, 1993;Hashimoto and Kuriyama, 1997;Hill, 1985;Nishikawa et al, 1997). For example, baclophen inhibits activation of adenylyl cyclase induced by forskolin (Nishikawa and Kuriyama, 1989) while enhancing the production of cAMP that results from the activation of receptors positively linked to adenylyl cyclase (Karbon and Enna, 1985;Knight and Bowery, 1996;Uezono et al, 1997).…”