title: Rhes regulates dopamine D2 receptor transmission in striatal cholinergic interneurons.
abstract: Ras homolog enriched in striatum (Rhes) is highly expressed in striatal medium spiny neurons (MSNs) of rodents. In the present study, we characterized the expression of Rhes mRNA across species, as well as its functional role in other striatal neuron subtypes. Double in situ hybridization analysis showed that Rhes transcript is selectively localized in striatal cholinergic interneurons (ChIs), but not in GABAergic parvalbumin- or in neuropeptide Y-positive cell populations. Rhes is closely linked to dopamine-dependent signaling. Therefore, we recorded ChIs activity in basal condition and following dopamine receptor activation. Surprisingly, instead of an expected dopamine D2 receptor (D2R)-mediated inhibition, we observed an aberrant excitatory response in ChIs from Rhes knockout mice. Conversely, the effect of D1R agonist on ChIs was less robust in Rhes mutants than in controls. Although Rhes deletion in mutants occurs throughout the striatum, we demonstrate that the D2R response is altered specifically in ChIs, since it was recorded in pharmacological isolation, and prevented either by intrapipette BAPTA or by GDP-β-S. Moreover, we show that blockade of Cav2.2 calcium channels prevented the abnormal D2R response. Finally, we found that the abnormal D2R activation in ChIs was rescued by selective PI3K inhibition thus suggesting that Rhes functionally modulates PI3K/Akt signaling pathway in these neurons. Our findings reveal that, besides its expression in MSNs, Rhes is localized also in striatal ChIs and, most importantly, lack of this G-protein, significantly alters D2R modulation of striatal cholinergic excitability.
authors.affiliation: Department of Systems Medicine, University of Rome "Tor Vergata", Via Oxford 1, 00133 Rome, Italy; IRCCS Fondazione Santa Lucia, Laboratory of Neurophysiology and Synaptic Plasticity, Via del Fosso di Fiorano 64, 00133 Rome, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Sciamanna
authors.affiliation: Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Via Pansini 5, 80131 Naples, Italy; CEINGE Biotecnologie Avanzate, Via G. Salvatore 486, 80145 Naples, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Napolitano
authors.affiliation: Department of Biology, University of Pisa, Via L. Ghini 13, 56126 Pisa, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Pelosi
authors.affiliation: IRCCS Fondazione Santa Lucia, Laboratory of Neurophysiology and Synaptic Plasticity, Via del Fosso di Fiorano 64, 00133 Rome, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Bonsi
authors.affiliation: CEINGE Biotecnologie Avanzate, Via G. Salvatore 486, 80145 Naples, Italy; Department of Health and Motor Sciences, DiSMeB, University of Naples "Parthenope", Via Medina 40, 80143, Naples, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Vitucci
authors.affiliation: CEINGE Biotecnologie Avanzate, Via G. Salvatore 486, 80145 Naples, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Nuzzo
authors.affiliation: CEINGE Biotecnologie Avanzate, Via G. Salvatore 486, 80145 Naples, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Punzo
authors.affiliation: Department of Philosophy and Human Sciences, University of Perugia, Piazza Ermini 1, 06123 Perugia (PG), Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: Ghiglieri
authors.affiliation: Department of Systems Medicine, University of Rome "Tor Vergata", Via Oxford 1, 00133 Rome, Italy; IRCCS Fondazione Santa Lucia, Laboratory of Neurophysiology and Synaptic Plasticity, Via del Fosso di Fiorano 64, 00133 Rome, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Ponterio
authors.affiliation: Department of Biology, University of Pisa, Via L. Ghini 13, 56126 Pisa, Italy; Istituto Italiano di Tecnologia, Center for Neuroscience and Cognitive Systems, Corso Bettini 31, 38068 Rovereto (TN), Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Pasqualetti
authors.affiliation: Department of Systems Medicine, University of Rome "Tor Vergata", Via Oxford 1, 00133 Rome, Italy; IRCCS Fondazione Santa Lucia, Laboratory of Neurophysiology and Synaptic Plasticity, Via del Fosso di Fiorano 64, 00133 Rome, Italy. Electronic address: pisani@uniroma2.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Pisani
authors.affiliation: CEINGE Biotecnologie Avanzate, Via G. Salvatore 486, 80145 Naples, Italy; Department of Environmental Sciences, Second University of Naples (SUN), Via Vivaldi 43, 81100 Caserta, Italy. Electronic address: usiello@ceinge.unina.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Usiello
mesh_terms: D000200:Action Potentials; D000293:Adolescent; D000328:Adult; D000818:Animals; D059329:Cholinergic Neurons / Q000378:metabolism / Q000502:physiology; D003342:Corpus Striatum / Q000378:metabolism / Q000502:physiology*; D005260:Female; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D007395:Interneurons / Q000378:metabolism / Q000502:physiology; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000502:physiology*; D015398:Signal Transduction; D013045:Species Specificity; D009435:Synaptic Transmission
chemical_list: D012333:RNA, Messenger; D017448:Receptors, Dopamine D2; D051057:Proto-Oncogene Proteins c-akt; D019204:GTP-Binding Proteins; C486702:RASD2 protein, human; C488189:Rasd2 protein, mouse
keywords: Calcium; Cholinergic interneurons; D2 dopamine receptors; Dystonia; Rhes; Striatum