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Rhes influences striatal cAMP/PKA-dependent signaling and synaptic plasticity in a gender-sensitive fashion.

Ghiglieri V, Napolitano F, Pelosi B, Schepisi C, Migliarini S, Di Maio A, Pendolino V, Mancini M, Sciamanna G, Vitucci D, Maddaloni G, Giampà C, Errico F, Nisticò R, Pasqualetti M, Picconi B, Usiello A - Sci Rep (2015)

Bottom Line: Corticostriatal LTP defects are exclusively found in A2AR/D2R-expressing MSNs of KO females, compared to KO males, an effect that is abolished by PKA inhibitors but not by the removal of circulating estrogens.This suggests that the synaptic alterations found in KO females could be triggered by an aberrant A2AR/cAMP/PKA activity, but not due to estrogen-mediated effect.Consistent with increased cAMP signaling, D1R-mediated motor stimulation, haloperidol-induced catalepsy and caffeine-evoked hyper-activity are robustly enhanced in Rhes KO females compared to mutant males.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Philosophy, Human, Social, and Educational Sciences, University of Perugia, Perugia, Italy [2] Fondazione Santa Lucia IRCCS, Rome, Italy.

ABSTRACT
Mechanisms of gender-specific synaptic plasticity in the striatum, a brain region that controls motor, cognitive and psychiatric functions, remain unclear. Here we report that Rhes, a GTPase enriched in medium spiny neurons (MSNs) of striatum, alters the striatal cAMP/PKA signaling cascade in a gender-specific manner. While Rhes knockout (KO) male mice, compared to wild-type (WT) mice, had a significant basal increase of cAMP/PKA signaling pathway, the Rhes KO females exhibited a much stronger response of this pathway, selectively under the conditions of dopamine/adenosine-related drug challenge. Corticostriatal LTP defects are exclusively found in A2AR/D2R-expressing MSNs of KO females, compared to KO males, an effect that is abolished by PKA inhibitors but not by the removal of circulating estrogens. This suggests that the synaptic alterations found in KO females could be triggered by an aberrant A2AR/cAMP/PKA activity, but not due to estrogen-mediated effect. Consistent with increased cAMP signaling, D1R-mediated motor stimulation, haloperidol-induced catalepsy and caffeine-evoked hyper-activity are robustly enhanced in Rhes KO females compared to mutant males. Thus Rhes, a thyroid hormone-target gene, plays a relevant role in gender-specific synaptic and behavioral responses.

No MeSH data available.


Related in: MedlinePlus

Intrinsic membrane properties and long-term depression in Rhes mutant mice.(A,B) Western blotting analysis on the striatal glutamate AMPAR and NMDAR subunit levels in male (A) (n = 6/genotype per GluA1, GluA2/3, GluN1, GluN2B; n = 5 WT, 6 KO per GluN2A), and female (B) (n = 6/genotype per GluA1, GluA2/3, GluN2A; n = 4 WT, 5 KO per GluN1; n = 6 WT, 5 KO per GluN2B) mice. The top panels show representative blots comparing the different genotypes, for each protein detected. All data are expressed as mean ± SEM. Genotypes are as indicated. (C,D) Current-voltage graphs (left) and representative traces (right) obtained after applying hyperpolarizing and depolarizing steps of current to MSNs recorded from WT (n = 6 males, n = 7 females) and KO (n = 10 per gender) mice. Time-courses (top) and example traces (bottom) of the post-synaptic responses measured in MSNs recorded from slices of male KO (n = 6) and WT (n = 5) mice (left panel) and female KO (n = 4) and WT (n = 5) mice (right panel), showing no difference in high-frequency stimulation (HFS)-induced LTD (Student’s t-test, pre- vs. 30 min post-HFS, **p < 0.01).
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f3: Intrinsic membrane properties and long-term depression in Rhes mutant mice.(A,B) Western blotting analysis on the striatal glutamate AMPAR and NMDAR subunit levels in male (A) (n = 6/genotype per GluA1, GluA2/3, GluN1, GluN2B; n = 5 WT, 6 KO per GluN2A), and female (B) (n = 6/genotype per GluA1, GluA2/3, GluN2A; n = 4 WT, 5 KO per GluN1; n = 6 WT, 5 KO per GluN2B) mice. The top panels show representative blots comparing the different genotypes, for each protein detected. All data are expressed as mean ± SEM. Genotypes are as indicated. (C,D) Current-voltage graphs (left) and representative traces (right) obtained after applying hyperpolarizing and depolarizing steps of current to MSNs recorded from WT (n = 6 males, n = 7 females) and KO (n = 10 per gender) mice. Time-courses (top) and example traces (bottom) of the post-synaptic responses measured in MSNs recorded from slices of male KO (n = 6) and WT (n = 5) mice (left panel) and female KO (n = 4) and WT (n = 5) mice (right panel), showing no difference in high-frequency stimulation (HFS)-induced LTD (Student’s t-test, pre- vs. 30 min post-HFS, **p < 0.01).

Mentions: Based on the strict control of glutamatergic inputs on MSNs activity, we first analyzed the striatal AMPAR and NMDAR subunit expression in WT and KO animals. Western blotting analysis indicated that protein levels of both NMDAR (GluN1, GluN2A and GluN2B) and AMPAR (GluA1 and GluA2/3) subunits are not altered in knockouts of both genders (Fig. 3A,B; p > 0.05, per each protein). Next, we examined the effects of Rhes deletion in modulating synaptic properties and plasticity of striatal MSNs in mutant mice. Based on intracellular and patch-clamp recordings in corticostriatal slices, we failed to find any significant difference between genotypes in the intrinsic membrane properties of MSNs (Fig. 3C,D, upper panels; Student’s t-test, p > 0.05). Moreover, analysis of activity-dependent synaptic plasticity in striatal MSNs revealed that the delivery of a high frequency stimulation (HFS) to corticostriatal fibers in presence of Mg2+ (1.2 M) was able to induce comparable long-term depression (LTD) in the MSNs of both genotypes, without any evident effect of gender (Fig. 3C,D, bottom panels; two way ANOVA, gender effect, male: F(1,136) = 0.71, p > 0.05; female: F(1,136) = 0.41, p > 0.05).


Rhes influences striatal cAMP/PKA-dependent signaling and synaptic plasticity in a gender-sensitive fashion.

Ghiglieri V, Napolitano F, Pelosi B, Schepisi C, Migliarini S, Di Maio A, Pendolino V, Mancini M, Sciamanna G, Vitucci D, Maddaloni G, Giampà C, Errico F, Nisticò R, Pasqualetti M, Picconi B, Usiello A - Sci Rep (2015)

Intrinsic membrane properties and long-term depression in Rhes mutant mice.(A,B) Western blotting analysis on the striatal glutamate AMPAR and NMDAR subunit levels in male (A) (n = 6/genotype per GluA1, GluA2/3, GluN1, GluN2B; n = 5 WT, 6 KO per GluN2A), and female (B) (n = 6/genotype per GluA1, GluA2/3, GluN2A; n = 4 WT, 5 KO per GluN1; n = 6 WT, 5 KO per GluN2B) mice. The top panels show representative blots comparing the different genotypes, for each protein detected. All data are expressed as mean ± SEM. Genotypes are as indicated. (C,D) Current-voltage graphs (left) and representative traces (right) obtained after applying hyperpolarizing and depolarizing steps of current to MSNs recorded from WT (n = 6 males, n = 7 females) and KO (n = 10 per gender) mice. Time-courses (top) and example traces (bottom) of the post-synaptic responses measured in MSNs recorded from slices of male KO (n = 6) and WT (n = 5) mice (left panel) and female KO (n = 4) and WT (n = 5) mice (right panel), showing no difference in high-frequency stimulation (HFS)-induced LTD (Student’s t-test, pre- vs. 30 min post-HFS, **p < 0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507147&req=5

f3: Intrinsic membrane properties and long-term depression in Rhes mutant mice.(A,B) Western blotting analysis on the striatal glutamate AMPAR and NMDAR subunit levels in male (A) (n = 6/genotype per GluA1, GluA2/3, GluN1, GluN2B; n = 5 WT, 6 KO per GluN2A), and female (B) (n = 6/genotype per GluA1, GluA2/3, GluN2A; n = 4 WT, 5 KO per GluN1; n = 6 WT, 5 KO per GluN2B) mice. The top panels show representative blots comparing the different genotypes, for each protein detected. All data are expressed as mean ± SEM. Genotypes are as indicated. (C,D) Current-voltage graphs (left) and representative traces (right) obtained after applying hyperpolarizing and depolarizing steps of current to MSNs recorded from WT (n = 6 males, n = 7 females) and KO (n = 10 per gender) mice. Time-courses (top) and example traces (bottom) of the post-synaptic responses measured in MSNs recorded from slices of male KO (n = 6) and WT (n = 5) mice (left panel) and female KO (n = 4) and WT (n = 5) mice (right panel), showing no difference in high-frequency stimulation (HFS)-induced LTD (Student’s t-test, pre- vs. 30 min post-HFS, **p < 0.01).
Mentions: Based on the strict control of glutamatergic inputs on MSNs activity, we first analyzed the striatal AMPAR and NMDAR subunit expression in WT and KO animals. Western blotting analysis indicated that protein levels of both NMDAR (GluN1, GluN2A and GluN2B) and AMPAR (GluA1 and GluA2/3) subunits are not altered in knockouts of both genders (Fig. 3A,B; p > 0.05, per each protein). Next, we examined the effects of Rhes deletion in modulating synaptic properties and plasticity of striatal MSNs in mutant mice. Based on intracellular and patch-clamp recordings in corticostriatal slices, we failed to find any significant difference between genotypes in the intrinsic membrane properties of MSNs (Fig. 3C,D, upper panels; Student’s t-test, p > 0.05). Moreover, analysis of activity-dependent synaptic plasticity in striatal MSNs revealed that the delivery of a high frequency stimulation (HFS) to corticostriatal fibers in presence of Mg2+ (1.2 M) was able to induce comparable long-term depression (LTD) in the MSNs of both genotypes, without any evident effect of gender (Fig. 3C,D, bottom panels; two way ANOVA, gender effect, male: F(1,136) = 0.71, p > 0.05; female: F(1,136) = 0.41, p > 0.05).

Bottom Line: Corticostriatal LTP defects are exclusively found in A2AR/D2R-expressing MSNs of KO females, compared to KO males, an effect that is abolished by PKA inhibitors but not by the removal of circulating estrogens.This suggests that the synaptic alterations found in KO females could be triggered by an aberrant A2AR/cAMP/PKA activity, but not due to estrogen-mediated effect.Consistent with increased cAMP signaling, D1R-mediated motor stimulation, haloperidol-induced catalepsy and caffeine-evoked hyper-activity are robustly enhanced in Rhes KO females compared to mutant males.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Philosophy, Human, Social, and Educational Sciences, University of Perugia, Perugia, Italy [2] Fondazione Santa Lucia IRCCS, Rome, Italy.

ABSTRACT
Mechanisms of gender-specific synaptic plasticity in the striatum, a brain region that controls motor, cognitive and psychiatric functions, remain unclear. Here we report that Rhes, a GTPase enriched in medium spiny neurons (MSNs) of striatum, alters the striatal cAMP/PKA signaling cascade in a gender-specific manner. While Rhes knockout (KO) male mice, compared to wild-type (WT) mice, had a significant basal increase of cAMP/PKA signaling pathway, the Rhes KO females exhibited a much stronger response of this pathway, selectively under the conditions of dopamine/adenosine-related drug challenge. Corticostriatal LTP defects are exclusively found in A2AR/D2R-expressing MSNs of KO females, compared to KO males, an effect that is abolished by PKA inhibitors but not by the removal of circulating estrogens. This suggests that the synaptic alterations found in KO females could be triggered by an aberrant A2AR/cAMP/PKA activity, but not due to estrogen-mediated effect. Consistent with increased cAMP signaling, D1R-mediated motor stimulation, haloperidol-induced catalepsy and caffeine-evoked hyper-activity are robustly enhanced in Rhes KO females compared to mutant males. Thus Rhes, a thyroid hormone-target gene, plays a relevant role in gender-specific synaptic and behavioral responses.

No MeSH data available.


Related in: MedlinePlus