Advanced
The GABAB receptor associates with regulators of G-protein signaling 4 protein in the mouse prefrontal cortex and hypothalamus
The GABAB receptor associates with regulators of G-protein signaling 4 protein in the mouse prefrontal cortex and hypothalamus
BMB Reports. 2014. Jun, 47(6): 324-329
Copyright © 2014, Korean Society for Biochemistry and Molecular Biology
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
  • Received : July 11, 2013
  • Accepted : September 12, 2013
  • Published : June 30, 2014
Download
PDF
e-PUB
PubReader
PPT
Export by style
Share
Article
Author
Metrics
Cited by
TagCloud
About the Authors
Gyeongwha Kim
Soonwoong Jung
Hyeonwi Son
Sujeong Kim
Jungil Choi
Dong Hoon Lee
Gu Seob Roh
Sang Soo Kang
Gyeong Jae Cho
Wan Sung Choi
Hyun Joon Kim
kimhj@gnu.kr

Abstract
Regulators of G-protein signaling (RGS) proteins regulate certain G-protein-coupled receptor (GPCR)-mediated signaling pathways. The GABA B receptor (GABA B R) is a GPCR that plays a role in the stress response. Previous studies indicate that acute immobilization stress (AIS) decreases RGS4 in the prefrontal cortex (PFC) and hypothalamus (HY) and suggest the possibility of a signal complex composed of RGS4 and GABA B R. Therefore, in the present study, we tested whether RGS4 associates with GABA B R in these brain regions. We found the co-localization of RGS4 and GABA B R subtypes in the PFC and HY using double immunohistochemistry and confirmed a direct association between GABA B2 R and RGS4 proteins using co-immunoprecipitation. Furthermore, we found that AIS decreased the amount of RGS4 bound to GABA B2 R and the number of double-positive cells. These results indicate that GABA B R forms a signal complex with RGS4 and suggests that RGS4 is a regulator of GABA B R. [BMB Reports 2014; 47(6): 324-329]
Keywords
INTRODUCTION
It is well known that regulators of G-protein signaling (RGS) proteins negatively regulate G-protein-coupled receptor (GPCR) signaling pathways via the GTPase-activating property of the RGS domain (1) . During stress response, numerous GPCR-mediated signaling pathways are activated or inactivated in the brain (2 , 3) . We previously investigated acute stress-responsive RGS proteins using a 2-h acute immobilization stress (AIS) paradigm and found a reduction of RGS4 in the prefrontal cortex (PFC) and hypothalamus (HY) of mice (4) . RGS4 mRNA is relatively abundant in several brain regions within the stress response circuitry, such as the cerebral cortex, amygdala, thalamus, paraventricular nucleus (PVN) of the HY, and locus coeruleus (LC) (5) , and RGS4 mRNA levels in the PVN and LC are regulated in opposite directions by chronic unpredictable stress and corticosterone (6) . RGS4 regulates the signaling of several Gα i/o - and Gα q -coupled receptors including group I metabotropic glutamate receptors (mGluRs) (7) , μ-opioid receptors (8) , M1-4 muscarinic receptors (9) , 5-hydroxytryptamine 1A/2A (serotonin) receptors (10) , and α2A-adrenergic receptors (11) . Moreover, some RGS4-related GPCRs are thought to be activated during acute stress, when RGS4 is reduced (4) .
To terminate acute stress responses, the inhibition of corticotrophin releasing hormone (CRH) is critical (12) and is mainly regulated by GABA-ergic signaling (13 - 15) . Among GABARs, GABA A R and GABA C R are ionotropic receptors, and GABABR is a GPCR (16) . GABABR is composed of GABA B1 R and GABA B2 R subunits, with GABA B1 R containing the GABA binding site and GABA B2 R responsible for Gα i/o protein activation (17) . GABABR is involved in stress-related physiological responses, including modulation of plasma interleukin-6 (IL-6) levels (18) , antinociception (19) , and mood disorders (20) . Moreover, a recent fluorescence resonance energy transfer (FRET) study suggests that the GABABR signaling complex interacts with RGS4 (21) . In the present study, therefore, we examined whether RGS4 proteins associate with GABA B R in the mouse brain upon AIS.
RESULTS
- AIS induced opposite changes in levels of RGS4 and plasma corticosterone
We confirmed the specificity of anti-RGS4 primary antibody using preabsorption with blocking peptide (Supplementary Fig. 1 ). The 2-h AIS paradigm is known to decrease RGS4 in the brain (4) , and acute stress is known to increase corticosterone (22) . A previous study also reports that RGS4 mRNA expression in the PVN is decreased by corticosterone (6) . Therefore, we investigated temporal changes of RGS4 and plasma corticosterone levels after AIS. RGS4 protein was reduced in the PFC and HY immediately after 2 h immobilization (IM) ( Fig. 1 ). RGS4 protein expression levels remained reduced 6 h after termination of IM (IM+6h) but recovered to control levels after 22 h (IM+22h). The lowest levelof RGS4 protein in the PFC and HYafter AIS was approximately 30% of control levels. In contrast to RGS4, plasma corticosterone levels rapidly increased after IM but declined 6 h after termination of IM. Corticosterone levels returned to basal levels 22 h after termination of AIS (IM+22h).
PPT Slide
Lager Image
RGS4 protein immediately decreased after acute stress in the PFC (F(4,9) = 15.43, P < 0.001) and HY (F(4,9) = 3.892, P = 0.0420) but returned to control levels 22 h after termination of IM. CTL, control IM, 2-h immobilization stress IM+2h, 2 h after termination of IM IM+6 h, 6 h after termination of IM IM+22h, 22 h after termination of IM. *P < 0.05, Dunnett post-hoc test. Plasma corticosterone levels quickly increased after IM and returned to basal levels 22 h after termination of IM (F(4,25) = 5.693, P = 0.002). ##P < 0.01, Dunnett post-hoc test.
- RGS4 and GABABR were co-localized and co-precipitated in the PFC and HY
To identify the positional relationship of RGS4 and GABA B R in the PFC and HY, double-immunohistochemistry (D-IHC) was performed using antibodies for RGS4 and GABA B1 R or GABA B2 R subunits ( Fig. 2 A). Double-positive cells were found in the PFC and PVN region of the HY. However, not all RGS4 signals overlapped with GABA B1 R or GABA B2 R signals, suggesting that RGS4 also modulates other GPCRs such as α 2A -adrenergic receptors or mGluR5 (11 , 23) .
PPT Slide
Lager Image
(A) RGS4 (red) and GABABR (green) were co-localized (yellow) in the PFC and PVN region of the HY in the CTL group. Each arrow indicates the area of magnification (insets). Scale bar = 50 μm. (B) RGS4 and Gαi co-precipitated with GABAB2R. Protein was immunoprecipitated with anti-GABAB2R antibody or normal rabbit serum (IgG control) and immunoblotted (IB) by anti-RGS4, anti-Gαi, or anti-GABAB2R antibody. Input protein (10 μg) was loaded in parallel. There were no size-matched bands in the IgG control lanes, indicating the specificity of co-IP with anti-GABAB2R antibody. Co-IP of the GABABR signal complex with anti-GABAB2R-antibodies from the PFC (C) and HY (D) in CTL and IM+2h groups. The precipitate was IB with the indicated antibodies. Note that the amount of RGS4 and Gαi bound to GABAB2R were decreased in the IM+2h group. Data are representative of results from at least three independent experiments (n = 3-5 per group). Similar results were obtained from each experiment.
To assess whether the endogenous RGS4 protein physically interacts with GABA B R in vivo , co-immunoprecipitation (IP) was performed under non-denaturing conditions ( Fig. 2 B). RGS4 and G αi were detected in the anti-GABA B2 R antibody precipitates, indicating a direct association between RGS4 and the GABA B R signal complex. A control experiment with normal IgG did not produce size-matched bands for RGS4, G αi , or GABA B2 R of the total input protein. After establishing the procedure for co-IP of anti-GABA B2 R antibody, we investigated whether the amount of RGS4 bound to the GABA B R signal complex was decreased by AIS in the PFC and HY ( Fig. 2 C and D). We found that precipitates from the anti-GABA B2 R antibody contained reduced amounts of RGS4 and Gα i protein from both brain regions in the stressed group (IM+2h) compared with the control (CTL) group.
- AIS decreased RGS4/GABABR double-positive cells
After confirming the association of RGS4 and GABA B R, we investigated whether AIS decreased the number of RGS4/GABA B2 R double-positive cells. D-IHC was performed on brain tissue from CTL and IM+2h groups ( Fig. 3 ). In the cingulate cortex (Cg1) of the PFC, there were no significant differences between groups in the number of GABA B2 R-positive cells, but the number of RGS4-positive cells and RGS4/GABA B2 R double-positive cells was lower in the IM+2h group compared with the CTL group ( Fig. 3 A and Supplementary Fig. 2 ). In the PVN, AIS decreased the number of RGS4-positive cells, resulting in a lower number of RGS4/GABA B2 R double-positive cells in the IM+2h group compared with the CTL group ( Fig. 3 B and Supplementary Fig. 3 ).
PPT Slide
Lager Image
(A) Expression of RGS4 protein (red) but not GABABR (green) decreased in the Cg1 region of the PFC in the IM+2 h group (left panel). Arrows indicate co-localization (yellow) of RGS4 and GABAB2R. Scale bars = 50 μm. The percentage of RGS4-positive and RGS4/GABAB2R double-positive cells was significantly decreased in the IM+2h group (n = 4, *P < 0.05). (B) Expression of RGS4 protein but not GABABR decreased in the lateral and medial magnocellular part (PaLM, PaMM) of the PVN region of the HY in the IM+2 h group (left panel). Arrows indicate co-localization of RGS4 and GABAB2R. Scale bars = 100 μm. The percentage of RGS4-positive and RGS4/GABAB2R double-positive cells was significantly decreased in the IM+2h group (n = 4, **P < 0.01).
DISCUSSION
We found that the AIS-responsive RGS4 protein was associated with GABA B R in the PFC and HY, suggesting that some stress-related GABAergic phenomena may be enhanced in regions, when RGS4 is decreased. In the Cg1 of the PFC, AIS decreased the number of RGS4 and GABA B R double-positive cells ( Fig. 3 A). It is not clear, however, which functions of the Cg1 might be affected by AIS-induced changes in the RGS4-GABA B R complex, as the Cg1 takes part in a variety of neural processes including attention (24) , emotion (25) , and cognition (26) . Although normal and disordered functions of the Cg1 are modulated by stressful environments (27) , many GPCRs are involved in these processes, including M 2-3 muscarinic, μ-opioid, α2-adrenergic, 5-hydroxytryptamine1A, and GABA B R (28) . Interestingly, with the exception of GABA B R, these receptors have already been recognized as RGS4-related GPCRs (8 - 11) , and GABA B R was found to be an RGS4-bound GPCR in the present study ( Fig. 2 ). Therefore, it is possible that additional RGS4-related GPCR signaling pathways may be changed by AIS. Also, stress-induced changes in neural activity could be accomplished by the cooperation of several GPCRs and not modulated by a single GPCR signaling pathway. This possibility is supported by our D-IHC results, which show partial co-localization of RGS4 with GABA B R ( Fig. 2 A and 3 A).
In the PVN of the CTL group, RGS4 and GABA B R double-positive cells were mainly localized in the parvocellular region, which contains CRH neurons (29) . The acute stress response begins with the release of CRH and ends with the blockade of CRH release from CRH-containing neurons via glucocorticoid negative feedback (6 , 22) . CRH release is negatively regulated by GABA in the PVN, which is largely mediated by GABA B R (15 , 30) . In the present study, we demonstrated a direct association of RGS4, GABA B2 R, and Gα i through in vivo co-IP ( Fig. 2 B) and showed that AIS decreased the amount of RGS4 protein bound to the GABA B R complex in the HY ( Fig. 2 D), consistent with a recent FRET study (21) . Additionally, the number of RGS4 and GABA B R double-positive cells was significantly decreased in the medial parvocellular region of PVN ( Fig. 3 B), where nearly half of the cells have been identified as GABAergic (31) . Thus, the decrease in RGS4 bound to GABA B R may result in a decrease in CRH release, which is supported by the observation of opposite changes in corticosterone and RGS4 levels after AIS ( Fig. 1 ). However, other RGS4-related GPCRs also exist in the PVN, and it has recently been suggested that the decrease in RGS4 by acute stress may lead to an increase in mGluR and μ-opioid receptor signaling in the PVN, which may contribute to stress adaptation (32) . Therefore, cooperative signaling changes related to RGS4 may also occur in the PVN during acute stress.
Although we cannot conclusively remark on its physiological significance, we confirmed the association between RGS4 and GABA B R in the PFC and HY after acute stress using in vivo co-IP and D-IHC. This association suggests a putative regulatory mechanism of GABA B R signaling in these two brain regions during acute stress responses. In previous studies, RGS2 and RGS7 were found to modulate G-protein-gated inwardly rectifying K + channels coupled with GABA B R in the ventral tegmental area and hippocampus, respectively (33 , 34) . A modulatory role of RGS6 in GABA B R signaling was also reported in the cerebellum (35) . These findings suggest that the modulation of various GABA B R signaling pathways is achieved by regionally and functionally specific RGS proteins. Therefore, future studies should aim to elucidate the role of RGS4 in the regulation of GABA B R signaling in the PFC and HY.
MATERIALS AND METHODS
- Animals and AIS treatment
Nine-week-old male C57BL/6 mice (SPF grade, Hana, Co. Ltd., Korea) were housed in a temperature-controlled (22℃) environment under a 12 h light/dark cycle (lights on at 6:00 AM), with free access to laboratory chow and water. The animals were habituated for 1 week before experiments. Mice in stress groups were placed in a plastic restrainer for 2 h in a separate room equipped with a 200-lux light and maintained at 22℃. Mice in the CTL group were kept in their home cage before sacrifice. Groups were divided into CTL, 2-h IM, 2 h after the termination of IM (IM+2h), 6 h after the termination of IM (IM+6h), and 22 h after the termination of IM (IM+22h). All procedures were approved by the Gyeongsang National University Institution Animal Care & Use Committee (GLA-100917-M0093).
- Enzyme-link immunosorbent assay (EIA) of plasma corticosterone
Mouse blood was collected in vacutainers containing K3EDTA. Plasma was isolated via centrifugation at 1,000×g for 15 min at 4℃. The samples were stored at −80℃ until the assay was performed. Quantification of plasma corticosterone levels was carried out using the corticosterone EIA kit (Cayman, MI, USA) according to the manufacturer’s protocol.
- Western blot analysis
Western blot analysis was performed as previously described (4) . Briefly, protein-transferred membranes were blocked and incubated with primary antibodies (anti-RGS4, 1:500, SC-6204; anti-GABA B2 R, 1:100, SC-28792; anti-G αi-3 , 1:500, SC-262; Santa Cruz Biotechnology, Santa Cruz, CA). Bound antibodies were detected with an enhanced chemiluminescence detection kit (Amersham Biosciences, Munich, Germany) according to the manufacturer’s protocol. For quantification of the results, each band density was read by SigmaGel software (Sigma). Each density was normalized using the corresponding α-tubulin density as an internal control.
- Immunohistochemistry
For histological studies, mice were perfused, and brain tissues were immunostained as previously described with some modifications (36) . For D-IHC, sections were incubated with mixed primary antibody solutions containing RGS4 (1:200) + GABA B1 R (1:100, SC-14006, Santa Cruz Biotechnology, Santa Cruz, CA) or RGS4 (1:200) + GABA B2 R (1:100) at 4℃ overnight. To detect primary antibodies, Alexa Fluor (AF)-594- and AF-488-conjugated secondary antibodies were used. Sections were mounted on gelatin-coated slides and coverslipped using a wet mount solution (Invitrogen, Carlsbad, CA). To count immuno-positive cells, four images (0.015 mm 2 ) were obtained from each group. Single- and double-positive cell numbers for RGS4 and GABA B2 R and total cell number covering the entire area were separately counted for each image (37) . Images were obtained using a spinning disk confocal microscope equipped with an Olympus Disk Spinning Unit (BX2-DSU) (38) .
- Co-immunoprecipitation
Total protein extracts were prepared in RIPA buffer (Tris-HCl: 50 mM, pH 7.4, 1% NP-40, 0.25% Na-deoxycholate, 150 mM NaCl, 1 mM EDTA) by grinding with a disposable polypropylene grinder followed by ultra-sonication. Protein concentration was assayed using the bicinchoninic acid assay (BCA) method. Lysates were stored at −70℃ in aliquots before further use. Equal amounts of protein lysates (800 μg each) were precleared once with 50 μl TrueBlot anti-rabbit IgG IP beads (eBioscience, San Diego, CA) on ice for 30 min and centrifuged at 10,000× g for 3 min. The supernatant was incubated with 5 μg primary antibody on ice for 1 h. After further incubation with 50 μg of anti-rabbit IgG beads for 2 h, immune complexes were collected by centrifugation at 10,000× g and washed three times using 500 μl RIPA buffer. Immunoprecipitates were mixed with sample buffer, dissociated by heating for 10 min, resolved with SDS-PAGE, and analyzed by western blotting (39) .
- Statistical analyses
Data were analyzed using one-way analysis of variance (ANOVA) and Dunnett post-hoc tests. For comparisons between two groups, t tests were used (GraphPad Prism 5.01). Data are presented as mean ± standard error (SE). Statistical significance was set at P < 0.05.
Acknowledgements
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (No. 2011-0025844).
References
De Vries L. , Zheng B. , Fischer T. , Elenko E. , Farquhar M. G. (2000) The regulator of G protein signaling family. Annu. Rev. Pharmacol. Toxicol. 40 235 - 271    DOI : 10.1146/annurev.pharmtox.40.1.235
Dedovic K. , Duchesne A. , Andrews J. , Engert V. , Pruessner J. C. (2009) The brain and the stress axis: The neural correlates of cortisol regulation in response to stress. NeuroImage 47 864 - 871    DOI : 10.1016/j.neuroimage.2009.05.074
Kiss A. , Aguilera G. (2000) Role of Alpha-1-Adrenergic Receptors in the Regulation of Corticotropin-Releasing Hormone mRNA in the Paraventricular Nucleus of the Hypothalamus During Stress. Cell Mol. Biol. 20 683 - 694
Kim G. , Lee Y. , Jeong E. Y. , Jung S. , Son H. , Lee D. H. , Roh G. S. , Kang S. S. , Cho G. J. , Choi W. S. , Kim H. J. (2010) Acute stress responsive RGS proteins in the mouse brain. Mol. Cells 30 161 - 165    DOI : 10.1007/s10059-010-0102-3
Gold S. J. , Ni Y. G. , Dohlman H. G. , Nestler E. J. (1997) Regulators of G-protein signaling (RGS) proteins: region-specific expression of nine subtypes in rat brain. J. Neurosci. 17 8024 - 8037
Ni Y. G. , Gold S. J. , Iredale P. A. , Terwilliger R. Z. , Duman R. S. , Nestler E. J. (1999) Region-specific regulation of RGS4 (Regulator of G-protein-signaling protein type 4) in brain by stress and glucocorticoids: in vivo and in vitro studies. J. Neurosci. 19 3674 - 3680
Saugstad J. A. , Marino M. J. , Folk J. A. , Hepler J. R. , Conn P. J. (1998) RGS4 inhibits signaling by group I metabotropic glutamate receptors. J. Neurosci. 18 905 - 913
Georgoussi Z. , Leontiadis L. , Mazarakou G. , Merkouris M. , Hyde K. , Hamm H. (2006) Selective interactions betw een G protein subunits and RGS4 with the C-terminal domains of the [mu]- and [delta]-opioid receptors regulate opioid receptor signaling. Cellular Signalling 18 771 - 782    DOI : 10.1016/j.cellsig.2005.07.003
Ding J. , Guzman J. N. , Tkatch T. , Chen S. , Goldberg J. A. , Ebert P. J. , Levitt P. , Wilson C. J. , Hamm H. E. , Surmeier D. J. (2006) RGS4-dependent attenuation of M4 autoreceptor function in striatal cholinergic interneurons following dopamine depletion. Nat. Neurosci. 9 832 - 842    DOI : 10.1038/nn1700
Ghavami A. , Hunt R. A. , Olsen M. A. , Zhang J. , Smith D. L. , Kalgaonkar S. , Rahman Z. , Young K. H. (2004) Differential effects of regulator of G protein signaling (RGS) proteins on serotonin 5-HT1A, 5-HT2A, and dopamine D2 receptor-mediated signaling and adenylyl cyclase activity. Cell Signal. 16 711 - 721    DOI : 10.1016/j.cellsig.2003.11.006
Cavalli A. , Druey K. M. , Milligan G. (2000) The regulator of G protein signaling RGS4 selectively enhances alpha 2A-adreoreceptor stimulation of the GTPase activity of Go1alpha and Gi2alpha. J. Biol. Chem. 275 23693 - 23699    DOI : 10.1074/jbc.M910395199
Herman J. P. , Cullinan W. E. , Morano M. I. , Akil H. , Watson S. J. (1995) Contribution of the ventral subiculum to inhibitory regulation of the hypothalamo-pituitary-adrenocortical axis. J. Neuroendocrinol. 7 475 - 482    DOI : 10.1111/j.1365-2826.1995.tb00784.x
Herman J. P. , Figueiredo H. , Mueller N. K. , Ulrich-Lai Y. , Ostrander M. M. , Choi D. C. , Cullinan W. E. (2003) Central mechanisms of stress integration: hierarchical circuitry controlling hypothalamo-pituitary-adrenocortical responsiveness. Front. Neuroendocrinol. 24 151 - 180    DOI : 10.1016/j.yfrne.2003.07.001
Kovacs K. J. , Miklos I. H. , Bali B. (2004) GABAergic mechanisms constraining the activity of the hypothalamo-pituitary-adrenocortical axis. Ann. N. Y. Acad. Sci. 1018 466 - 476    DOI : 10.1196/annals.1296.057
Calogero A. E. , Gallucci W. T. , Chrousos G. P. , Gold P. W. (1988) Interaction between GABAergic neurotransmission and rat hypothalamic corticotropin-releasing hormone secretion in vitro. Brain Res. 463 28 - 36    DOI : 10.1016/0006-8993(88)90523-9
Terunuma M. , Pangalos M. N. , Moss S. J. , Thomas P. B. (2010) Functional Modulation of GABAB Receptors by Protein Kinases and Receptor Trafficking; in: Advances in Pharmacology Academic Press New York, USA 113 - 122
Margeta-Mitrovic M. , Jan Y. N. , Jan L. Y. (2001) Function of GB1 and GB2 subunits in G protein coupling of GABA(B) receptors. Proc. Natl. Acad. Sci. U. S. A. 98 14649 - 14654    DOI : 10.1073/pnas.251554498
Song D. K. , Suh H. W. , Huh S. O. , Jung J. S. , Ihn B. M. , Choi I. G. , Kim Y. H. (1998) Central GABAA and GABAB receptor modulation of basal and stress-induced plasma interleukin-6 levels in mice. J. Pharmacol. Exp. Ther. 287 144 - 149
Houston A. J. , Wong J. C. , Ebenezer I. S. (1997) A study on the involvement of GABAB receptor ligands in stress-induced antinociception in male mice. Methods. Find. Exp. Clin. Pharmacol. 19 167 - 171
Frankowska M. , Filip M. , Przegalinski E. (2007) Effects of GABAB receptor ligands in animal tests of depression and anxiety. Pharmacol. Rep. 59 645 - 655
Fowler C. E. , Aryal P. , Suen K. F. , Slesinger P. A. (2007) Evidence for association of GABA(B) receptors with Kir3 channels and regulators of G protein signalling (RGS4) proteins. J. Physiol. 580 51 - 65    DOI : 10.1113/jphysiol.2006.123216
Markovic V. M. , Cupic Z. , Vukojevic V. , Kolar-Anic L. (2011) Predictive modeling of the hypothalamic-pituitary-adrenal (HPA) axis response to acute and chronic stress. Endocr. J. 58 889 - 904    DOI : 10.1507/endocrj.EJ11-0037
Schwendt M. , McGinty J. F. (2007) Regulator of G-protein signaling 4 interacts with metabotropic glutamate receptor subtype 5 in rat striatum: relevance to amphetamine behavioral sensitization. J. Pharmacol. Exp. Ther. 323 650 - 657    DOI : 10.1124/jpet.107.128561
Botvinick M. , Nystrom L. E. , Fissell K. , Carter C. S. , Cohen J. D. (1999) Conflict monitoring versus selectionfor-action in anterior cingulate cortex. Nature 402 179 - 181    DOI : 10.1038/46035
Davidson R. J. , Abercrombie H. , Nitschke J. B. , Putnam K. (1999) Regional brain function, emotion and disorders of emotion. Curr. Opin. Neurobiol. 9 228 - 234    DOI : 10.1016/S0959-4388(99)80032-4
MacDonald A. W., , Cohen J. D. , Stenger V. A. , Carter C. S. (2000) Dissociating the role of the dorsolateral prefrontal and anterior cingulate cortex in cognitive control. Science 288 1835 - 1838    DOI : 10.1126/science.288.5472.1835
McEwen B. S. , Eiland L. , Hunter R. G. , Miller M. M. (2011) Stress and anxiety: Structural plasticity and epigenetic regulation as a consequence of stress. Neuropharmacology 62 3 - 12    DOI : 10.1016/j.neuropharm.2011.07.014
Palomero-Gallagher N. , Vogt B. A. , Schleicher A. , Mayberg H. S. , Zilles K. (2009) Receptor architecture of human cingulate cortex: evaluation of the four-region neurobiological model. Hum. Brain. Mapp. 30 2336 - 2355    DOI : 10.1002/hbm.20667
Whitnall M. H. (1993) Regulation of the hypothalamic corticotropin-releasing hormone neurosecretory system. Prog. Neurobiol. 40 573 - 629    DOI : 10.1016/0301-0082(93)90035-Q
Marques de Souza L. , Franci C. R. (2008) GABAergic mediation of stress-induced secretion of corticosterone and oxytocin, but not prolactin, by the hypothalamic paraventricular nucleus. Life Sci. 83 686 - 692    DOI : 10.1016/j.lfs.2008.09.007
Tasker J. G. , Dudek F. E. (1993) Local inhibitory synaptic inputs to neurones of the paraventricular nucleus in slices of rat hypothalamus. J. Physiol. 469 179 - 192
Wamsteeker Cusulin J. I. , Fuzesi T. , Inoue W. , Bains J. S. (2013) Glucocorticoid feedback uncovers retrograde opioid signaling at hypothalamic synapses. Nat. Neurosci. 16 596 - 604    DOI : 10.1038/nn.3374
Labouebe G. , Lomazzi M. , Cruz H. G. , Creton C. , Lujan R. , Li M. , Yanagawa Y. , Obata K. , Watanabe M. , Wickman K. , Boyer S. B. , Slesinger P. A. , Luscher C. (2007) RGS2 modulates coupling between GABAB receptors and GIRK channels in dopamine neurons of the ventral tegmental area. Nat. Neurosci. 10 1559 - 1568    DOI : 10.1038/nn2006
Fajardo-Serrano A. , Wydeven N. , Young D. , Watanabe M. , Shigemoto R. , Martemyanov K. A. , Wickman K. , Lujan R. (2013) Association of Rgs7/Gbeta5 complexes with girk channels and GABA receptors in hippocampal CA1 pyramidal neurons. Hippocampus 23 1231 - 1245    DOI : 10.1002/hipo.22161
Maity B. , Stewart A. , Yang J. , Loo L. , Sheff D. , Shepherd A. J. , Mohapatra D. P. , Fisher R. A. (2012) Regulator of G protein signaling 6 (RGS6) protein ensures coordination of motor movement by modulating GABAB receptor signaling. J. Biol. Chem. 287 4972 - 4981    DOI : 10.1074/jbc.M111.297218
Jung S. , Lee Y. , Kim G. , Son H. , Lee D. H. , Roh G.S. , Kang S. S. , Cho G. J. , Choi W. S. , Kim H. J. (2012) Decreased expression of extracellular matrix proteins and trophic factors in the amygdala complex of depressed mice after chronic immobilization stress. BMC Neurosci. 13 58 -    DOI : 10.1186/1471-2202-13-58
Kim H. J. , Gieske M. C. , Hudgins S. , Kim B. G. , Krust A. , Chambon P. , Ko C. (2007) Estrogen receptor alpha-induced cholecystokinin type A receptor expression in the female mouse pituitary. J. Endocrinol. 195 393 - 405    DOI : 10.1677/JOE-07-0358
Oh Y. J. , Na J. , Jeong J. H. , Park D. K. , Park K. H. , Ko J. S. , Kim D. S. (2012) Alterations in hyperpolarizationactivated cyclic nucleotidegated cation channel (HCN) expression in the hippocampus following pilocarpine-induced status epilepticus. BMB Rep. 45 635 - 640    DOI : 10.5483/BMBRep.2012.45.11.091
Huang Z. M. , Wu J. , Jia Z. C. , Tian Y. , Tang J. , Tang Y. , Wang Y. , Wu Y. Z. , Ni B. (2012) Identification of interacting proteins of retinoid-related orphan nuclear receptor gamma in HepG2 cells. BMB Rep. 45 331 - 336    DOI : 10.5483/BMBRep.2012.45.6.249