1
|
Wang JY, Weng WC, Wang TQ, Liu Y, Qiu DL, Wu MC, Chu CP. Noradrenaline depresses facial stimulation-evoked cerebellar MLI-PC synaptic transmission via α2-AR/PKA signaling cascade in vivo in mice. Sci Rep 2023; 13:15908. [PMID: 37741947 PMCID: PMC10517918 DOI: 10.1038/s41598-023-42975-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 09/17/2023] [Indexed: 09/25/2023] Open
Abstract
The noradrenergic fibers of the locus coeruleus, together with mossy fibers and climbing fibers, comprise the three types of cerebellar afferents that modulate the cerebellar neuronal circuit. We previously demonstrated that noradrenaline (NA) modulated synaptic transmission in the mouse cerebellar cortex via adrenergic receptors (ARs). In the present study, we investigated the effect of NA on facial stimulation-evoked cerebellar molecular layer interneuron (MLI)-Purkinje cell (PC) synaptic transmission in urethane-anesthetized mice using an in vivo cell-attached recording technique and a pharmacological method. MLI-PC synaptic transmission was induced by air-puff stimulation (duration: 60 ms) of the ipsilateral whisker pad, which exhibited positive components (P1 and P2) accompanied by a pause in simple spike activity. Cerebellar molecular layer application of NA (15 µM) decreased the amplitude and area under the curve of P1, and the pause in simple spike activity, but increased the P2/P1 ratio. The NA-induced decrease in P1 amplitude was concentration-dependent, and the half-inhibitory concentration was 10.94 µM. The NA-induced depression of facial stimulation-evoked MLI-PC GABAergic synaptic transmission was completely abolished by blockade of α-ARs or α2-ARs, but not by antagonism of α1-ARs or β-ARs. Bath application of an α2-AR agonist inhibited MLI-PC synaptic transmission and attenuated the effect of NA on the synaptic response. NA-induced depression of MLI-PC synaptic transmission was completely blocked by a mixture of α2A- and 2B-AR antagonists, and was abolished by inhibition of protein kinase A. In addition, electrical stimulation of the molecular layer evoked MLI-PC GABAergic synaptic transmission in the presence of an AMPA receptor antagonist, which was inhibited by NA through α2-ARs. Our results indicate that NA inhibits MLI-PC GABAergic synaptic transmission by reducing GABA release via an α2-AR/PKA signaling pathway.
Collapse
Affiliation(s)
- Jun-Ya Wang
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
- Department of Physiology, College of Basic Medicine, Jilin Medical University, Jilin, 132013, Jilin, China
| | - Wen-Cai Weng
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
- Department Radiology, Dalian Xinhua Hospital, Dalian University, Dalian, China
| | - Ting-Qi Wang
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - Yue Liu
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
- Department of Physiology, College of Basic Medicine, Jilin Medical University, Jilin, 132013, Jilin, China
| | - De-Lai Qiu
- Department of Physiology, College of Basic Medicine, Jilin Medical University, Jilin, 132013, Jilin, China
| | - Mao-Cheng Wu
- Department of Osteology, Affiliated Hospital of Yanbian University, Yanji, 133002, Jilin, China.
| | - Chun-Ping Chu
- Department of Physiology, College of Basic Medicine, Jilin Medical University, Jilin, 132013, Jilin, China.
| |
Collapse
|
2
|
Benarroch E. What Is the Role of Norepinephrine in Cerebellar Modulation and Stress-Induced Episodic Ataxia? Neurology 2023; 100:383-386. [PMID: 36806456 PMCID: PMC9984211 DOI: 10.1212/wnl.0000000000206882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 12/09/2022] [Indexed: 02/22/2023] Open
|
3
|
Wahis J, Holt MG. Astrocytes, Noradrenaline, α1-Adrenoreceptors, and Neuromodulation: Evidence and Unanswered Questions. Front Cell Neurosci 2021; 15:645691. [PMID: 33716677 PMCID: PMC7947346 DOI: 10.3389/fncel.2021.645691] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/03/2021] [Indexed: 12/27/2022] Open
Abstract
Noradrenaline is a major neuromodulator in the central nervous system (CNS). It is released from varicosities on neuronal efferents, which originate principally from the main noradrenergic nuclei of the brain - the locus coeruleus - and spread throughout the parenchyma. Noradrenaline is released in response to various stimuli and has complex physiological effects, in large part due to the wide diversity of noradrenergic receptors expressed in the brain, which trigger diverse signaling pathways. In general, however, its main effect on CNS function appears to be to increase arousal state. Although the effects of noradrenaline have been researched extensively, the majority of studies have assumed that noradrenaline exerts its effects by acting directly on neurons. However, neurons are not the only cells in the CNS expressing noradrenaline receptors. Astrocytes are responsive to a range of neuromodulators - including noradrenaline. In fact, noradrenaline evokes robust calcium transients in astrocytes across brain regions, through activation of α1-adrenoreceptors. Crucially, astrocytes ensheath neurons at synapses and are known to modulate synaptic activity. Hence, astrocytes are in a key position to relay, or amplify, the effects of noradrenaline on neurons, most notably by modulating inhibitory transmission. Based on a critical appraisal of the current literature, we use this review to argue that a better understanding of astrocyte-mediated noradrenaline signaling is therefore essential, if we are ever to fully understand CNS function. We discuss the emerging concept of astrocyte heterogeneity and speculate on how this might impact the noradrenergic modulation of neuronal circuits. Finally, we outline possible experimental strategies to clearly delineate the role(s) of astrocytes in noradrenergic signaling, and neuromodulation in general, highlighting the urgent need for more specific and flexible experimental tools.
Collapse
Affiliation(s)
- Jérôme Wahis
- Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
- Leuven Brain Institute, Leuven, Belgium
| | - Matthew G. Holt
- Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
- Leuven Brain Institute, Leuven, Belgium
| |
Collapse
|
4
|
Perez DM. α 1-Adrenergic Receptors in Neurotransmission, Synaptic Plasticity, and Cognition. Front Pharmacol 2020; 11:581098. [PMID: 33117176 PMCID: PMC7553051 DOI: 10.3389/fphar.2020.581098] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/11/2020] [Indexed: 12/14/2022] Open
Abstract
α1-adrenergic receptors are G-Protein Coupled Receptors that are involved in neurotransmission and regulate the sympathetic nervous system through binding and activating the neurotransmitter, norepinephrine, and the neurohormone, epinephrine. There are three α1-adrenergic receptor subtypes (α1A, α1B, α1D) that are known to play various roles in neurotransmission and cognition. They are related to two other adrenergic receptor families that also bind norepinephrine and epinephrine, the β- and α2-, each with three subtypes (β1, β2, β3, α2A, α2B, α2C). Previous studies assessing the roles of α1-adrenergic receptors in neurotransmission and cognition have been inconsistent. This was due to the use of poorly-selective ligands and many of these studies were published before the characterization of the cloned receptor subtypes and the subsequent development of animal models. With the availability of more-selective ligands and the development of animal models, a clearer picture of their role in cognition and neurotransmission can be assessed. In this review, we highlight the significant role that the α1-adrenergic receptor plays in regulating synaptic efficacy, both short and long-term synaptic plasticity, and its regulation of different types of memory. We will also present evidence that the α1-adrenergic receptors, and particularly the α1A-adrenergic receptor subtype, are a potentially good target to treat a wide variety of neurological conditions with diminished cognition.
Collapse
Affiliation(s)
- Dianne M Perez
- The Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, OH, United States
| |
Collapse
|
5
|
Inoshita T, Hirano T. Norepinephrine Facilitates Induction of Long-term Depression through β-Adrenergic Receptor at Parallel Fiber-to-Purkinje Cell Synapses in the Flocculus. Neuroscience 2020; 462:141-150. [PMID: 32502572 DOI: 10.1016/j.neuroscience.2020.05.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 05/12/2020] [Accepted: 05/21/2020] [Indexed: 10/24/2022]
Abstract
The cerebellum is involved in motor learning, and long-term depression (LTD) at parallel fiber-to-Purkinje cell (PF-PC) synapses has been considered to be a primary cellular mechanism for motor learning. In addition, the contribution of norepinephrine (NE) to cerebellum-dependent learning paradigms has been reported. Thus, the roles of LTD and of NE in motor learning have been studied separately, and the relationship between the effects of NE and LTD remains unclear. Here, we examined effects of β-adrenergic receptor (β-AR) activity on the synaptic transmission and LTD at PF-PC synapses in the cerebellar flocculus. The flocculus regulates adaptation of oculomotor reflexes, and we previously reported the involvement of both LTD and β-AR in adaptation of an oculomotor reflex. Here we found that specific agonists for β-AR or NE did not directly change synaptic transmission, but lowered the threshold for LTD induction at PF-PC synapses in the flocculus. In addition, protein kinase A (PKA), which is activated downstream of β-AR, facilitated the LTD induction. Altogether, these results suggest that NE facilitates LTD induction at PF-PC synapses in the flocculus by activating PKA through β-AR.
Collapse
Affiliation(s)
- Takuma Inoshita
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Tomoo Hirano
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
| |
Collapse
|
6
|
Choy JMC, Agahari FA, Li L, Stricker C. Noradrenaline Increases mEPSC Frequency in Pyramidal Cells in Layer II of Rat Barrel Cortex via Calcium Release From Presynaptic Stores. Front Cell Neurosci 2018; 12:213. [PMID: 30100867 PMCID: PMC6072855 DOI: 10.3389/fncel.2018.00213] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 06/28/2018] [Indexed: 11/20/2022] Open
Abstract
Somatosensory cortex is innervated by afferents originating from the locus coeruleus which typically release noradrenaline. We tested if activation of presynaptic α1-adrenoceptors (AR) coupled to a Gq-mediated signaling cascade resulted in calcium (Ca2+) release from stores and thereby increased spontaneous transmitter release in rat barrel cortex. Adding 1–100 μM noradrenaline (NA) or 5 μM cirazoline (CO), a α1-AR specific agonist, to the standard artificial cerebrospinal fluid increased the frequency of miniature excitatory postsynaptic currents (mEPSC) by 64 ± 7% in 51% of pyramidal cells in layer II (responders) with no effect on the amplitude. In 42 responders, the mEPSC frequency during control was significantly smaller (39 ± 2 vs. 53 ± 4 Hz) and upon NA exposure, the input resistance (Rin) decreased (9 ± 7%) compared to non-responders. Experiments using CO and the antagonist prazosin revealed that NA acted via binding to α1-ARs, which was further corroborated by simultaneously blocking β- and α2-ARs with propranolol and yohimbine, which did not prevent the increase in mEPSC frequency. To verify elements in the signaling cascade, both the phospholipase C inhibitor edelfosine and the membrane permeable IP3 receptor blocker 2-APB averted the increase in mEPSC frequency. Likewise, emptying Ca2+ stores with cyclopiazonic acid or the chelation of intracellular Ca2+ with BAPTA-AM prevented the frequency increase, suggesting that the frequency increase was caused by presynaptic store release. When group I metabotropic glutamate receptors were activated with DHPG, co-application of NA occluded a further frequency increase suggesting that the two receptor activations may not signal independently of each other. The increased mEPSC frequency in a subset of pyramidal cells results in enhanced synaptic noise, which, together with the reduction in Rin, will affect computation in the network.
Collapse
Affiliation(s)
- Julian M C Choy
- Neuronal Network Laboratory, Eccles Institute of Neuroscience, The John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Fransiscus A Agahari
- Neuronal Network Laboratory, Eccles Institute of Neuroscience, The John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia.,Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
| | - Li Li
- Neuronal Network Laboratory, Eccles Institute of Neuroscience, The John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia.,Zhejiang Provincial Key Laboratory of Anesthesiology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China
| | - Christian Stricker
- Neuronal Network Laboratory, Eccles Institute of Neuroscience, The John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia.,ANU Medical School, Australian National University, Canberra, ACT, Australia
| |
Collapse
|
7
|
Hoxha E, Tempia F, Lippiello P, Miniaci MC. Modulation, Plasticity and Pathophysiology of the Parallel Fiber-Purkinje Cell Synapse. Front Synaptic Neurosci 2016; 8:35. [PMID: 27857688 PMCID: PMC5093118 DOI: 10.3389/fnsyn.2016.00035] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 10/19/2016] [Indexed: 12/24/2022] Open
Abstract
The parallel fiber-Purkinje cell (PF-PC) synapse represents the point of maximal signal divergence in the cerebellar cortex with an estimated number of about 60 billion synaptic contacts in the rat and 100,000 billions in humans. At the same time, the Purkinje cell dendritic tree is a site of remarkable convergence of more than 100,000 parallel fiber synapses. Parallel fiber activity generates fast postsynaptic currents via α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, and slower signals, mediated by mGlu1 receptors, resulting in Purkinje cell depolarization accompanied by sharp calcium elevation within dendritic regions. Long-term depression (LTD) and long-term potentiation (LTP) have been widely described for the PF-PC synapse and have been proposed as mechanisms for motor learning. The mechanisms of induction for LTP and LTD involve different signaling mechanisms within the presynaptic terminal and/or at the postsynaptic site, promoting enduring modification in the neurotransmitter release and change in responsiveness to the neurotransmitter. The PF-PC synapse is finely modulated by several neurotransmitters, including serotonin, noradrenaline and acetylcholine. The ability of these neuromodulators to gate LTP and LTD at the PF-PC synapse could, at least in part, explain their effect on cerebellar-dependent learning and memory paradigms. Overall, these findings have important implications for understanding the cerebellar involvement in a series of pathological conditions, ranging from ataxia to autism. For example, PF-PC synapse dysfunctions have been identified in several murine models of spino-cerebellar ataxia (SCA) types 1, 3, 5 and 27. In some cases, the defect is specific for the AMPA receptor signaling (SCA27), while in others the mGlu1 pathway is affected (SCA1, 3, 5). Interestingly, the PF-PC synapse has been shown to be hyper-functional in a mutant mouse model of autism spectrum disorder, with a selective deletion of Pten in Purkinje cells. However, the full range of methodological approaches, that allowed the discovery of the physiological principles of PF-PC synapse function, has not yet been completely exploited to investigate the pathophysiological mechanisms of diseases involving the cerebellum. We, therefore, propose to extend the spectrum of experimental investigations to tackle this problem.
Collapse
Affiliation(s)
- Eriola Hoxha
- Neuroscience Institute Cavalieri Ottolenghi (NICO) and Department of Neuroscience, University of TorinoTorino, Italy
| | - Filippo Tempia
- Neuroscience Institute Cavalieri Ottolenghi (NICO) and Department of Neuroscience, University of TorinoTorino, Italy
| | | | | |
Collapse
|
8
|
Liu J, Julnes PS, Chen J, Ehrlich S, Walton E, Calhoun VD. The association of DNA methylation and brain volume in healthy individuals and schizophrenia patients. Schizophr Res 2015; 169:447-452. [PMID: 26381449 PMCID: PMC4681600 DOI: 10.1016/j.schres.2015.08.035] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 08/22/2015] [Accepted: 08/24/2015] [Indexed: 12/12/2022]
Abstract
Both methylation and brain volume patterns hold important biological information for the development and prognosis of schizophrenia (SZ). A combined study to probe the association between them provides a new perspective to understanding SZ. Genomic methylation of peripheral blood and regional brain volumes derived from magnetic resonance imaging were analyzed using parallel independent component analyses in this study. Nine methylation components and five brain volumetric components were extracted for 94 SZ patients and 106 healthy controls. After controlling for age, sex, race, and substance use, a component comprised primarily of bilateral cerebellar volumes was significantly correlated to a methylation component from 14 CpG sites in 13 genes. Both patients and healthy controls demonstrated similar associations, but patients had significantly smaller cerebellar volumes and dysmethylation in the associated epigenetic component compared to controls. The 13 genes are enriched in cellular growth and proliferation with some genes involved in neuronal growth and cerebellum development (GATA4, ADRA1D, EPHA3, and KCNK10), and these genes are prominently associated with neurological and psychological disorders. Such findings suggest that the methylation pattern of the genes coding for cellular growth may influence the cerebellar development through regulating gene expression, and the alteration in the methylation of these genes in SZ patients may contribute to the cerebellar volume reduction observed in patients.
Collapse
Affiliation(s)
- Jingyu Liu
- The Mind Research Network, Albuquerque, NM, USA; Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, USA.
| | | | - Jiayu Chen
- The Mind Research Network, Albuquerque, NM, USA
| | - Stefan Ehrlich
- Department of Child and Adolescent Psychiatry, TU-Dresden, Faculty of Medicine, Germany,MGH/MIT/HMS Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Esther Walton
- Department of Child and Adolescent Psychiatry, TU-Dresden, Faculty of Medicine, Germany
| | - Vince D. Calhoun
- The Mind Research Network, Albuquerque, NM, USA,Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, USA
| |
Collapse
|
9
|
Velásquez-Martínez MC, Vázquez-Torres R, Rojas LV, Sanabria P, Jiménez-Rivera CA. Alpha-1 adrenoreceptors modulate GABA release onto ventral tegmental area dopamine neurons. Neuropharmacology 2014; 88:110-21. [PMID: 25261018 DOI: 10.1016/j.neuropharm.2014.09.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 08/29/2014] [Accepted: 09/01/2014] [Indexed: 01/08/2023]
Abstract
The ventral tegmental area (VTA) plays an important role in reward and motivational processes involved in drug addiction. Previous studies have shown that alpha1-adrenoreceptors (α1-AR) are primarily found pre-synaptically at this area. We hypothesized that GABA released onto VTA-dopamine (DA) cells is modulated by pre-synaptic α1-AR. Recordings were obtained from putative VTA-DA cells of male Sprague-Dawley rats (28-50 days postnatal) using whole-cell voltage clamp technique. Phenylephrine (10 μM; α1-AR agonist) decreased the amplitude of GABAA receptor-mediated inhibitory postsynaptic currents (IPSCs) evoked by electrical stimulation of afferent fibers (n = 7; p < 0.05). Prazosin (1 μM, α1-AR antagonist), blocked this effect. Paired-pulse ratios were increased by phenylephrine application (n = 13; p < 0.05) indicating a presynaptic site of action. Spontaneous IPSCs frequency but not amplitude, were decreased in the presence of phenylephrine (n = 7; p < 0.05). However, frequency or amplitude of miniature IPSCs were not changed (n = 9; p > 0.05). Phenylephrine in low Ca(2+) (1 mM) medium decreased IPSC amplitude (n = 7; p < 0.05). Chelerythrine (a protein kinase C inhibitor) blocked the α1-AR action on IPSC amplitude (n = 6; p < 0.05). Phenylephrine failed to decrease IPSCs amplitude in the presence of paxilline, a BK channel blocker (n = 7; p < 0.05). Taken together, these results demonstrate that α1-ARs at presynaptic terminals can modulate GABA release onto VTA-DA cells. Drug-induced changes in α1-AR could contribute to the modifications occurring in the VTA during the addiction process.
Collapse
Affiliation(s)
- Maria C Velásquez-Martínez
- Department of Physiology, Medical Sciences Campus, University of Puerto Rico, San Juan, PR, USA; Laboratorio de Neurociencias y Comportamiento, Departamento de Ciencias Básicas, Facultad de Salud, Universidad Industrial de Santander, Bucaramanga, Colombia
| | - Rafael Vázquez-Torres
- Department of Physiology, Medical Sciences Campus, University of Puerto Rico, San Juan, PR, USA
| | - Legier V Rojas
- Department of Physiology, Universidad Central del Caribe, Bayamón, PR, USA
| | - Priscila Sanabria
- Department of Physiology, Universidad Central del Caribe, Bayamón, PR, USA
| | - Carlos A Jiménez-Rivera
- Department of Physiology, Medical Sciences Campus, University of Puerto Rico, San Juan, PR, USA.
| |
Collapse
|
10
|
Hirono M, Nagao S, Obata K. Developmental α2-adrenergic regulation of noradrenergic synaptic facilitation at cerebellar GABAergic synapses. Neuroscience 2014; 256:242-51. [DOI: 10.1016/j.neuroscience.2013.10.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 10/10/2013] [Accepted: 10/14/2013] [Indexed: 10/26/2022]
|
11
|
Jin XT, Cui N, Zhong W, Jin X, Wu Z, Jiang C. Pre- and postsynaptic modulations of hypoglossal motoneurons by α-adrenoceptor activation in wild-type and Mecp2(-/Y) mice. Am J Physiol Cell Physiol 2013; 305:C1080-90. [PMID: 23986203 DOI: 10.1152/ajpcell.00109.2013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypoglossal motoneurons (HNs) control tongue movement and play a role in maintenance of upper airway patency. Defects in these neurons may contribute to the development of sleep apnea and other cranial motor disorders including Rett syndrome (RTT). HNs are modulated by norepinephrine (NE) through α-adrenoceptors. Although postsynaptic mechanisms are known to play a role in this effect, how NE modulates the synaptic transmissions of HNs remains poorly understood. More importantly, the NE system is defective in RTT, while how the defect affects HNs is unknown. Believing that information of NE modulation of HNs may help the understanding of RTT and the design of new therapeutical interventions to motor defects in the disease, we performed these studies in which glycinergic inhibitory postsynaptic currents and intrinsic membrane properties were examined in wild-type and Mecp2(-/Y) mice, a mouse of model of RTT. We found that activation of α1-adrenoceptor facilitated glycinergic synaptic transmission and excited HNs. These effects were mediated by both pre- and postsynaptic mechanisms. The latter effect involved an inhibition of barium-sensitive G protein-dependent K(+) currents. The pre- and postsynaptic modulations of the HNs by α1-adrenoceptors were not only retained in Mecp2-null mice but also markedly enhanced, which appears to be a compensatory mechanism for the deficiencies in NE and GABAergic synaptic transmission. The existence of the endogenous compensatory mechanism is an encouraging finding, as it may allow therapeutical modalities to alleviate motoneuronal defects in RTT.
Collapse
Affiliation(s)
- Xiao-Tao Jin
- Department of Biology, Georgia State University, Atlanta, Georgia
| | | | | | | | | | | |
Collapse
|
12
|
Wang HX, Waterhouse BD, Gao WJ. Selective suppression of excitatory synapses on GABAergic interneurons by norepinephrine in juvenile rat prefrontal cortical microcircuitry. Neuroscience 2013; 246:312-28. [PMID: 23684615 DOI: 10.1016/j.neuroscience.2013.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 04/12/2013] [Accepted: 05/02/2013] [Indexed: 11/29/2022]
Abstract
The noradrenergic system of the brain is thought to facilitate neuronal processes that promote behavioral activation, alertness, and attention. It is known that norepinephrine (NE) can be significantly elevated in the prefrontal cortex under normal conditions such as arousal and attention, and following the administration of psychostimulants and various other drugs prescribed for psychiatric disorders. However, how NE modulates neuronal activity and synapses in the local prefrontal circuitry remains elusive. In this study, we characterized the actions of NE on individual monosynaptic connections among layer V pyramidal neurons (P) and fast-spiking (FS) GABAergic interneurons in the juvenile (postnatal days 20-23) rat prefrontal local circuitry. We found that NE selectively depresses excitatory synaptic transmission in P-FS connections but has no detectable effect on the excitatory synapses in P-P connections and the inhibitory synapses in FS-P connections. NE apparently exerts distinctly different modulatory actions on identified synapses that target GABAergic interneurons but has no effect on those in the pyramidal neurons in this specific developmental period. These results indicate that, depending on the postsynaptic targets, the effects of NE in prefrontal cortex are synapse-specific, at least in the juvenile animals.
Collapse
Affiliation(s)
- H-X Wang
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States
| | | | | |
Collapse
|
13
|
Salgado H, Garcia-Oscos F, Martinolich L, Hall S, Restom R, Tseng KY, Atzori M. Pre- and postsynaptic effects of norepinephrine on γ-aminobutyric acid-mediated synaptic transmission in layer 2/3 of the rat auditory cortex. Synapse 2011; 66:20-8. [DOI: 10.1002/syn.20979] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 07/26/2011] [Accepted: 08/25/2011] [Indexed: 11/08/2022]
|
14
|
Hertz L, Lovatt D, Goldman SA, Nedergaard M. Adrenoceptors in brain: cellular gene expression and effects on astrocytic metabolism and [Ca(2+)]i. Neurochem Int 2010; 57:411-20. [PMID: 20380860 PMCID: PMC2934885 DOI: 10.1016/j.neuint.2010.03.019] [Citation(s) in RCA: 163] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2009] [Revised: 03/02/2010] [Accepted: 03/31/2010] [Indexed: 11/24/2022]
Abstract
Recent in vivo studies have established astrocytes as a major target for locus coeruleus activation (Bekar et al., 2008), renewing interest in cell culture studies on noradrenergic effects on astrocytes in primary cultures and calling for additional information about the expression of adrenoceptor subtypes on different types of brain cells. In the present communication, mRNA expression of alpha(1)-, alpha(2)- and beta-adrenergic receptors and their subtypes was determined in freshly isolated, cell marker-defined populations of astrocytes, NG2-positive cells, microglia, endothelial cells, and Thy1-positive neurons (mainly glutamatergic projection neurons) in murine cerebral cortex. Immediately after dissection of frontal, parietal and occipital cortex of 10-12-week-old transgenic mice, which combined each cell-type marker with a specific fluorescent signal, the tissue was digested, triturated and centrifuged, yielding a solution of dissociated cells of all types, which were separated by fluorescence-activated cell sorting (FACS). mRNA expression in each cell fraction was determined by microarray analysis. alpha(1A)-Receptors were unequivocally expressed in astrocytes and NG2-positive cells, but absent in other cell types, and alpha(1B)-receptors were not expressed in any cell population. Among alpha(2)-receptors only alpha(2A)-receptors were expressed, unequivocally in astrocytes and NG-positive cells, tentatively in microglia and questionably in Thy1-positive neurons and endothelial cells. beta(1)-Receptors were unequivocally expressed in astrocytes, tentatively in microglia, and questionably in neurons and endothelial cells, whereas beta(2)-adrenergic receptors showed tentative expression in neurons and astrocytes and unequivocal expression in other cell types. This distribution was supported by immunochemical data and its relevance established by previous studies in well-differentiated primary cultures of mouse astrocytes, showing that stimulation of alpha(2)-adrenoceptors increases glycogen formation and oxidative metabolism, the latter by a mechanism depending on intramitochondrial Ca(2+), whereas alpha(1)-adrenoceptor stimulation enhances glutamate uptake, and beta-adrenoceptor activation causes glycogenolysis and increased Na(+), K(+)-ATPase activity. The Ca(2+)- and cAMP-mediated association between energy-consuming and energy-yielding processes is emphasized.
Collapse
MESH Headings
- Animals
- Astrocytes/metabolism
- Brain Chemistry/genetics
- Brain Chemistry/physiology
- Calcium Signaling/physiology
- Cell Separation
- Cells, Cultured
- Flow Cytometry
- Gene Expression/physiology
- Glucose/metabolism
- Glycogen/metabolism
- Mice
- Mice, Transgenic/physiology
- Microarray Analysis
- Mitochondria/metabolism
- Oxidation-Reduction
- Pyruvic Acid/metabolism
- RNA/biosynthesis
- RNA/genetics
- Receptors, Adrenergic/biosynthesis
- Receptors, Adrenergic/genetics
- Receptors, Adrenergic, alpha-1/biosynthesis
- Receptors, Adrenergic, alpha-1/genetics
- Receptors, Adrenergic, alpha-2/biosynthesis
- Receptors, Adrenergic, alpha-2/genetics
- Receptors, Adrenergic, beta/biosynthesis
- Receptors, Adrenergic, beta/genetics
Collapse
Affiliation(s)
- Leif Hertz
- Department of Clinical Pharmacology, College of Basic Medical Sciences, China Medical University, Shenyang, P. R. China
| | - Ditte Lovatt
- Division of Glial Disease and Therapeutics, Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY 14642
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642
| | - Steven A. Goldman
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642
| | - Maiken Nedergaard
- Division of Glial Disease and Therapeutics, Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY 14642
| |
Collapse
|
15
|
Docherty JR. Subtypes of functional alpha1-adrenoceptor. Cell Mol Life Sci 2010; 67:405-17. [PMID: 19862476 PMCID: PMC11115521 DOI: 10.1007/s00018-009-0174-4] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 09/11/2009] [Accepted: 10/05/2009] [Indexed: 11/29/2022]
Abstract
In this review, subtypes of functional alpha1-adrenoceptor are discussed. These are cell membrane receptors, belonging to the seven-transmembrane-spanning G-protein-linked family of receptors, which respond to the physiological agonist noradrenaline. alpha1-Adrenoceptors can be divided into alpha1A-, alpha1B- and alpha1D-adrenoceptors, all of which mediate contractile responses involving Gq/11 and inositol phosphate turnover. A fourth alpha1-adrenoceptor, the alpha1L-, represents a functional phenotype of the alpha1A-adrenoceptor. alpha1-Adrenoceptor subtype knock-out mice have refined our knowledge of the functions of alpha-adrenoceptor subtypes, particuarly as subtype-selective agonists and antagonists are not available for all subtypes. alpha1-Adrenoceptors function as stimulatory receptors involved particularly in smooth muscle contraction, especially contraction of vascular smooth muscle, both in local vasoconstriction and in the control of blood pressure and temperature, and contraction of the prostate and bladder neck. Central actions are now being elucidated.
Collapse
MESH Headings
- Animals
- Blood Pressure/physiology
- Body Temperature Regulation
- Drug Inverse Agonism
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- Inositol Phosphates/metabolism
- Mice
- Mice, Knockout
- Muscle, Smooth/physiology
- Muscle, Smooth, Vascular/physiology
- Receptors, Adrenergic, alpha-1/classification
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, Adrenergic, alpha-1/physiology
- Second Messenger Systems/physiology
- Vasoconstriction/physiology
Collapse
Affiliation(s)
- James R Docherty
- Department of Physiology, Royal College of Surgeons in Ireland, 123, St. Stephen's Green, Dublin 2, Ireland.
| |
Collapse
|
16
|
Hirono M, Yamada M, Obata K. Ethanol enhances both action potential-dependent and action potential-independent GABAergic transmission onto cerebellar Purkinje cells. Neuropharmacology 2009; 57:109-20. [PMID: 19426745 DOI: 10.1016/j.neuropharm.2009.04.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 04/14/2009] [Accepted: 04/22/2009] [Indexed: 11/19/2022]
Abstract
Ethanol (EtOH) modulates synaptic efficacy in various brain areas, including the cerebellum, which plays a role in motor coordination. Previous studies have shown that EtOH enhances tonic inhibition of cerebellar granule cells, which is one of the possible reasons for the alcohol-induced motor impairment. However, the effects of EtOH on molecular layer interneurons (MLIs) in the mouse cerebellum have remained unknown. Here we found that MLIs were depolarized by EtOH through enhancement of hyperpolarization-activated cationic currents (I(h)). Under physiological conditions, a low EtOH concentration (3-50 mM) caused a small increase in the firing rate of MLIs, whereas, in the presence of blockers for ionotropic glutamate and GABA receptors, EtOH (>or=10 mM) robustly enhanced MLI firing, suggesting that synaptic inputs, which seem to serve as the phasic inhibition, could suppress the EtOH-mediated excitation of MLIs and Purkinje cells (PCs). Even in the absence of synaptic blockers, a high EtOH concentration (100 mM) markedly increased the firing rate of MLIs to enhance GABAergic transmission. Furthermore, 100 mM EtOH-facilitated miniature IPSCs via a mechanism that depended on intracellular cyclic AMP, voltage-dependent Ca(2+) channels, and intracellular Ca(2+) stores, but was independent of I(h) or PKA. The two distinct effects of a high EtOH concentration (>or=100 mM), however, failed to attenuate the EtOH-induced strong depolarization of MLIs. These results suggest that acute exposure to a low EtOH concentration (<or=50 mM) enhanced GABAergic synaptic transmission, which suppressed the EtOH-evoked excitation of MLIs and PCs, thereby maintaining precise synaptic integration of PCs.
Collapse
Affiliation(s)
- Moritoshi Hirono
- Yamada Research Unit, RIKEN Brain Science Institute, Wako, Saitama, Japan.
| | | | | |
Collapse
|
17
|
Hirono M, Matsunaga W, Chimura T, Obata K. Developmental enhancement of alpha2-adrenoceptor-mediated suppression of inhibitory synaptic transmission onto mouse cerebellar Purkinje cells. Neuroscience 2008; 156:143-54. [PMID: 18691636 DOI: 10.1016/j.neuroscience.2008.07.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Revised: 07/09/2008] [Accepted: 07/10/2008] [Indexed: 01/04/2023]
Abstract
Noradrenaline (NA) modulates glutamatergic and GABAergic transmission in various areas of the brain. It is reported that some alpha2-adrenoceptor subtypes are expressed in the cerebellar cortex and alpha2-adrenoceptors may play a role in motor coordination. Our previous study demonstrated that the selective alpha2-adrenoceptor agonist clonidine partially depresses spontaneous inhibitory postsynaptic currents (sIPSCs) in mouse cerebellar Purkinje cells (PCs). Here we found that the inhibitory effect of clonidine on sIPSCs was enhanced during postnatal development. The activation of alpha2-adrenoceptors by clonidine did not affect sIPSCs in PCs at postnatal days (P) 8-10, when PCs showed a few sIPSCs and interneurons in the molecular layer (MLIs) did not cause action potential (AP). In the second postnatal week, the frequency of sIPSCs increased temporarily and reached a plateau at P14. By contrast, MLIs began to fire at P11 with the firing rate gradually increasing thereafter and reaching a plateau at P21. In parallel with this rise in the rate of firing, the magnitude of the clonidine-mediated inhibition of sIPSCs increased during postnatal development. Furthermore, the magnitude of the clonidine-mediated firing suppression in MLIs, which seemed to be mediated by a reduction in amplitude of the hyperpolarization-activated nonselective cation current, I(h), was constant across development. Both alpha2A- and alpha2B-, but not alpha2C-, adrenoceptors were strongly expressed in MLIs at P13, and P31. Therefore, the developmental enhancement of the clonidine-mediated inhibition of sIPSCs is attributed to an age-dependent increase in AP-derived sIPSCs, which can be blocked by clonidine. Thus, presynaptic activation of alpha2-adrenoceptors inhibits cerebellar inhibitory synaptic transmission after the second postnatal week, leading to a restriction of NA signaling, which is mainly mediated by alpha1- and beta2-adrenoceptors in the adult cerebellar neuronal circuit.
Collapse
Affiliation(s)
- M Hirono
- Neuronal Circuit Mechanisms Research Group, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
| | | | | | | |
Collapse
|
18
|
Di Mauro M, Bronzi D, Li Volsi G, Licata F, Lombardo P, Santangelo F. Noradrenaline modulates neuronal responses to GABA in vestibular nuclei. Neuroscience 2008; 153:1320-31. [PMID: 18440712 DOI: 10.1016/j.neuroscience.2008.02.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Revised: 02/14/2008] [Accepted: 02/14/2008] [Indexed: 11/24/2022]
Abstract
The effects of noradrenaline (NA) on the inhibitory responses to GABA were studied in vivo in neurons of the vestibular nuclei of the rat using extracellular recordings of single unit electrical activity and a microiontophoretic technique of drug application in loco. NA application influenced GABA-evoked inhibitions in 82% of tested neurons, depressing them in 42% and enhancing them in 40% of cases. The more frequent action of NA on GABA responses was depressive in lateral and superior vestibular nuclei (50% of neurons) and enhancing in the remaining nuclei (56% of neurons). The most intense effect of NA application was the enhancement of GABA responses induced in a population of lateral vestibular nucleus neurons, characterized by a background firing rate significantly higher than that of other units. The alpha(2) noradrenergic receptor agonist clonidine mimicked the enhancing action of NA on GABA responses; this action was blocked by application of the specific alpha(2) antagonist yohimbine. The beta adrenergic agonist isoproterenol induced either depressive or enhancing effects on GABA responses; the former more than the latter were totally or partially blocked by application of the beta antagonist timolol. It is concluded that NA enhances GABA responses by acting on noradrenergic alpha(2) and to a lesser extent beta receptors, whereas depressive action involves beta receptors only. These results confirm the hypothesis that the noradrenergic system participates in the regulation of the vestibulospinal and the vestibulo-ocular reflexes and suggest that conspicuous changes of NA content in brain due to aging or stress could lead to a deterioration in the mechanisms of normal vestibular function.
Collapse
Affiliation(s)
- M Di Mauro
- Department of Physiological Sciences, University of Catania, Viale Andrea Doria 6, Catania, Italy
| | | | | | | | | | | |
Collapse
|