1
|
Liu J, Liu X, Zhou WY, Gan J, Wang J, Zhang Q, Li JL, Shen ZS, Zhang YY, Tang QY, Zhang Z. The activation of GABAergic neurons in the hypothalamic tuberomammillary nucleus attenuates sevoflurane and propofol-induced anesthesia in mice. Front Pharmacol 2023; 14:1153735. [PMID: 37426823 PMCID: PMC10325722 DOI: 10.3389/fphar.2023.1153735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 06/08/2023] [Indexed: 07/11/2023] Open
Abstract
Background: The histaminergic neurons in the hypothalamic tuberomammillary nucleus (TMN) have been suggested to play a vital role in maintaining a rising state. But the neuronal types of the TMN are in debate and the role of GABAergic neurons remains unclear. Methods: In the present study, we examined the role of TMN GABAergic neurons in general anesthesia using chemogenetics and optogenetics strategies to regulate the activity of TMN GABAergic neurons. Results: The results indicated that either chemogenetic or optogenetic activation of TMN GABAergic neurons in mice decreased the effect of sevoflurane and propofol anesthesia. In contrast, inhibition of the TMN GABAergic neurons facilitates the sevoflurane anesthesia effect. Conclusion: Our results suggest that the activity of TMN GABAergic neurons produces an anti-anesthesia effect in loss of consciousness and analgesia.
Collapse
Affiliation(s)
- Jing Liu
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou Medical University, Xuzhou, Jiangsu, China
- Department of Cell Biology and Neurobiology, Life Sciences College, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Xiao Liu
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Wen-Yu Zhou
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Jun Gan
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Jie Wang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Qi Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Jun-Liang Li
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Zhong-Shan Shen
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Yue-Ying Zhang
- Department of Anesthesia, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Qiong-Yao Tang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Zhe Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu, China
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou Medical University, Xuzhou, Jiangsu, China
| |
Collapse
|
2
|
Siskos N, Ververidis C, Skavdis G, Grigoriou ME. Genoarchitectonic Compartmentalization of the Embryonic Telencephalon: Insights From the Domestic Cat. Front Neuroanat 2022; 15:785541. [PMID: 34975420 PMCID: PMC8716433 DOI: 10.3389/fnana.2021.785541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 11/16/2021] [Indexed: 11/13/2022] Open
Abstract
The telencephalon develops from the alar plate of the secondary prosencephalon and is subdivided into two distinct divisions, the pallium, which derives solely from prosomere hp1, and the subpallium which derives from both hp1 and hp2 prosomeres. In this first systematic analysis of the feline telencephalon genoarchitecture, we apply the prosomeric model to compare the expression of a battery of genes, including Tbr1, Tbr2, Pax6, Mash1, Dlx2, Nkx2-1, Lhx6, Lhx7, Lhx2, and Emx1, the orthologs of which alone or in combination, demarcate molecularly distinct territories in other species. We characterize, within the pallium and the subpallium, domains and subdomains topologically equivalent to those previously described in other vertebrate species and we show that the overall genoarchitectural map of the E26/27 feline brain is highly similar to that of the E13.5/E14 mouse. In addition, using the same approach at the earlier (E22/23 and E24/25) or later (E28/29 and E34/35) stages we further analyze neurogenesis, define the timing and duration of several developmental events, and compare our data with those from similar mouse studies; our results point to a complex pattern of heterochronies and show that, compared with the mouse, developmental events in the feline telencephalon span over extended periods suggesting that cats may provide a useful animal model to study brain patterning in ontogenesis and evolution.
Collapse
Affiliation(s)
- Nikistratos Siskos
- Laboratory of Developmental Biology & Molecular Neurobiology, Department of Molecular Biology & Genetics, Democritus University of Thrace, Alexandroupolis, Greece
| | - Charalampos Ververidis
- Obstetrics and Surgery Unit, Companion Animal Clinic, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - George Skavdis
- Laboratory of Molecular Regulation & Diagnostic Technology, Department of Molecular Biology & Genetics, Democritus University of Thrace, Alexandroupolis, Greece
| | - Maria E Grigoriou
- Laboratory of Developmental Biology & Molecular Neurobiology, Department of Molecular Biology & Genetics, Democritus University of Thrace, Alexandroupolis, Greece
| |
Collapse
|
3
|
Kajita Y, Mushiake H. Heterogeneous GAD65 Expression in Subtypes of GABAergic Neurons Across Layers of the Cerebral Cortex and Hippocampus. Front Behav Neurosci 2021; 15:750869. [PMID: 34803625 PMCID: PMC8595203 DOI: 10.3389/fnbeh.2021.750869] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/16/2021] [Indexed: 11/13/2022] Open
Abstract
Gamma-aminobutyric acid (GABA), a major inhibitory transmitter in the central nervous system, is synthesized via either of two enzyme isoforms, GAD65 or GAD67. GAD65 is synthesized in the soma but functions at synaptic terminals in an activity-dependent manner, playing a distinct role in excitatory-inhibitory balance. However, the extent to which each GABAergic subtype expresses GAD65 in the resting state remains unclear. In this study, we compared GAD65 expression among six GABAergic subtypes: NPY+, nNOS+, PV+, SOM+, CR+, and CCK+. According to the results, the GABAergic subtypes were classified into two groups per region based on GAD65 expression levels: high-expression (NPY+ and nNOS+) and low-expression groups (PV+, SOM+, CR+, and CCK+) in the cerebral cortex and high-expression (NPY+, nNOS+, and CCK+) and low-expression groups (PV+, SOM+, and CR+) in the hippocampus. Moreover, these expression patterns revealed a distinct laminar distribution in the cerebral cortex and hippocampus. To investigate the extent of GAD65 transport from the soma to synaptic terminals, we examined GAD65 expression in colchicine-treated rats in which GAD65 was synthesized in the soma but not transported to terminals. We found a significant positive correlation in GAD65 expression across subtypes between colchicine-treated and control rats. In summary, each GABAergic subtype exhibits a distinct GAD65 expression pattern across layers of the cerebral cortex and hippocampus. In addition, the level of GAD65 expression in the soma can be used as a proxy for the amount of GAD65 in the cytoplasm. These findings suggest that exploration of the distinct profiles of GAD65 expression among GABAergic subtypes could clarify the roles that GABAergic subtypes play in maintaining the excitatory-inhibitory balance.
Collapse
Affiliation(s)
- Yuki Kajita
- Department of Physiology, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Hajime Mushiake
- Department of Physiology, Graduate School of Medicine, Tohoku University, Sendai, Japan
| |
Collapse
|
4
|
Understanding the Significance of the Hypothalamic Nature of the Subthalamic Nucleus. eNeuro 2021; 8:ENEURO.0116-21.2021. [PMID: 34518367 PMCID: PMC8493884 DOI: 10.1523/eneuro.0116-21.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 08/05/2021] [Accepted: 08/20/2021] [Indexed: 11/21/2022] Open
Abstract
The subthalamic nucleus (STN) is an essential component of the basal ganglia and has long been considered to be a part of the ventral thalamus. However, recent neurodevelopmental data indicated that this nucleus is of hypothalamic origin which is now commonly acknowledged. In this work, we aimed to verify whether the inclusion of the STN in the hypothalamus could influence the way we understand and conduct research on the organization of the whole ventral and posterior diencephalon. Developmental and neurochemical data indicate that the STN is part of a larger glutamatergic posterior hypothalamic region that includes the premammillary and mammillary nuclei. The main anatomic characteristic common to this region involves the convergent cortical and pallidal projections that it receives, which is based on the model of the hyperdirect and indirect pathways to the STN. This whole posterior hypothalamic region is then integrated into distinct functional networks that interact with the ventral mesencephalon to adjust behavior depending on external and internal contexts.
Collapse
|
5
|
Panthi S, Lyons NMA, Leitch B. Impact of Dysfunctional Feed-Forward Inhibition on Glutamate Decarboxylase Isoforms and γ-Aminobutyric Acid Transporters. Int J Mol Sci 2021; 22:ijms22147740. [PMID: 34299369 PMCID: PMC8306481 DOI: 10.3390/ijms22147740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 07/16/2021] [Indexed: 12/02/2022] Open
Abstract
Absence seizures are associated with generalised synchronous 2.5–4 Hz spike-wave discharges causing brief and sudden alteration of awareness during childhood, which is known as childhood absence epilepsy (CAE). CAE is also associated with impaired learning, psychosocial challenges, and physical danger. Absence seizures arise from disturbances within the cortico-thalamocortical (CTC) network, including dysfunctional feed-forward inhibition (FFI); however, the precise mechanisms remain unclear. In epileptic stargazers, a genetic mouse model of CAE with chronic seizures, levels of γ-aminobutyric acid (GABA), and expression of GABA receptors are altered within the CTC network, implicating altered GABAergic transmission in absence seizures. However, the expression of GABA synthesising enzymes (GAD65 and GAD67) and GABA transporters (GAT-1 and 3) have not yet been characterised within absence seizure models. We found a specific upregulation of GAD65 in the somatosensory cortex but not the thalamus of epileptic stargazer mice. No differences were detected in GAD67 and GAT-3 levels in the thalamus or somatosensory cortex. Then, we assessed if GAD65 upregulation also occurred in Gi-DREADD mice exhibiting acute absence seizures, but we found no change in the expression profiles of GAD65/67 or GAT-3. Thus, the upregulation of GAD65 in stargazers may be a compensatory mechanism in response to long-term dysfunctional FFI and chronic absence seizures.
Collapse
Affiliation(s)
| | | | - Beulah Leitch
- Correspondence: ; Tel.: +64-3-479-7618; Fax: +64-3-479-7254
| |
Collapse
|
6
|
Gordon-Fennell A, Gordon-Fennell L, Desaivre S, Marinelli M. The Lateral Preoptic Area and Its Projection to the VTA Regulate VTA Activity and Drive Complex Reward Behaviors. Front Syst Neurosci 2020; 14:581830. [PMID: 33224029 PMCID: PMC7669548 DOI: 10.3389/fnsys.2020.581830] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 08/27/2020] [Indexed: 11/22/2022] Open
Abstract
The ventral tegmental area (VTA) underlies motivation and reinforcement of natural rewards. The lateral preoptic area (LPO) is an anterior hypothalamic brain region that sends direct projections to the VTA and to other brain structures known to regulate VTA activity. Here, we investigated the functional connection between the LPO and subpopulations of VTA neurons and explored the reinforcing and valence qualities of the LPO in rats. We found that the LPO and the LPO→VTA pathway inhibit the activity of VTA GABA neurons and have mixed effects on VTA dopamine neurons. Furthermore, we found that the LPO supports operant responding but drives avoidance, and we explored the apparent discrepancy between these two results. Finally, using fiber photometry, we show that the LPO signals aversive events but not rewarding events. Together, our findings demonstrate that the LPO modulates the activity of the VTA and drives motivated behavior and represents an overlooked modulator of reinforcement.
Collapse
Affiliation(s)
- Adam Gordon-Fennell
- Department of Neuroscience, College of Natural Sciences, University of Texas at Austin, Austin, TX, United States
| | - Lydia Gordon-Fennell
- Department of Neuroscience, College of Natural Sciences, University of Texas at Austin, Austin, TX, United States
| | - Stève Desaivre
- Department of Neuroscience, College of Natural Sciences, University of Texas at Austin, Austin, TX, United States
| | - Michela Marinelli
- Department of Neuroscience, College of Natural Sciences, University of Texas at Austin, Austin, TX, United States.,Department of Neurology, Dell Medical School, University of Texas at Austin, Austin, TX, United States.,Department of Psychiatry, Dell Medical School, University of Texas at Austin, Austin, TX, United States.,Division of Pharmacology and Toxicology, College of Pharmacy, University of Texas at Austin, Austin, TX, United States
| |
Collapse
|
7
|
Sbai O, Soussi R, Bole A, Khrestchatisky M, Esclapez M, Ferhat L. The actin binding protein α-actinin-2 expression is associated with dendritic spine plasticity and migrating granule cells in the rat dentate gyrus following pilocarpine-induced seizures. Exp Neurol 2020; 335:113512. [PMID: 33098872 DOI: 10.1016/j.expneurol.2020.113512] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/08/2020] [Accepted: 10/19/2020] [Indexed: 12/24/2022]
Abstract
α-actinin-2 (α-actn-2) is an F-actin-crosslinking protein, localized in dendritic spines. In vitro studies suggested that it is involved in spinogenesis, morphogenesis, actin organization, cell migration and anchoring of the NR1 subunit of the N-methyl-D-aspartate (NMDA) receptors in dendritic spines. However, little is known regarding its function in vivo. We examined the levels of α-actn-2 expression within the dentate gyrus (DG) during the development of chronic limbic seizures (epileptogenesis) induced by pilocarpine in rats. In this model, plasticity of the DG glutamatergic granule cells including spine loss, spinogenesis, morphogenesis, neo-synaptogenesis, aberrant migration, and alterations of NMDA receptors have been well characterized. We showed that α-actn-2 immunolabeling was reduced in the inner molecular layer at 1-2 weeks post-status epilepticus (SE), when granule cell spinogenesis and morphogenesis occur. This low level persisted at the chronic stage when new functional synapses are established. This decreased of α-actn-2 protein is concomitant with the recovery of drebrin A (DA), another actin-binding protein, at the chronic stage. Indeed, we demonstrated in cultured cells that in contrast to DA, α-actn-2 did not protect F-actin destabilization and DA inhibited α-actn-2 binding to F-actin. Such alteration could affect the anchoring of NR1 in dendritic spines. Furthermore, we showed that the expression of α-actn-2 and NR1 are co-down-regulated in membrane fractions of pilocarpine animals at chronic stage. Last, we showed that α-actn-2 is expressed in migrating newly born granule cells observed within the hilus of pilocarpine-treated rats. Altogether, our results suggest that α-actn-2 is not critical for the structural integrity and stabilization of granule cell dendritic spines. Instead, its expression is regulated when spinogenesis and morphogenesis occur and within migrating granule cells. Our data also suggest that the balance between α-actn-2 and DA expression levels may modulate NR1 anchoring within dendritic spines.
Collapse
Affiliation(s)
- Oualid Sbai
- Aix-Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France
| | - Rabia Soussi
- Aix-Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France
| | - Angélique Bole
- Aix-Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France
| | | | - Monique Esclapez
- Aix-Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | - Lotfi Ferhat
- Aix-Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France.
| |
Collapse
|
8
|
Beyeler A, Dabrowska J. Neuronal diversity of the amygdala and the bed nucleus of the stria terminalis. HANDBOOK OF BEHAVIORAL NEUROSCIENCE 2020; 26:63-100. [PMID: 32792868 DOI: 10.1016/b978-0-12-815134-1.00003-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Anna Beyeler
- Neurocentre Magendie, French National Institutes of Health (INSERM) unit 1215, Neurocampus of Bordeaux University, Bordeaux, France
| | - Joanna Dabrowska
- Center for the Neurobiology of Stress Resilience and Psychiatric Disorders, Discipline of Cellular and Molecular Pharmacology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States
| |
Collapse
|
9
|
Wearne TA, Cornish JL. Inhibitory regulation of the prefrontal cortex following behavioral sensitization to amphetamine and/or methamphetamine psychostimulants: A review of GABAergic mechanisms. Prog Neuropsychopharmacol Biol Psychiatry 2019; 95:109681. [PMID: 31255648 DOI: 10.1016/j.pnpbp.2019.109681] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 06/18/2019] [Accepted: 06/26/2019] [Indexed: 12/30/2022]
Abstract
Behavioral sensitization to repeated psychostimulant administration has been proposed to reflect many of the neurochemical and behavioral changes that are characteristic of a range of disorders, including drug addiction and psychoses. While previous studies have examined the role of dopamine and glutamate neurotransmission in mediating sensitization, particularly within the prefrontal cortex (PFC), the role of inhibitory GABAergic processing of the PFC in the expression of sensitization is not well understood. Recent research, however, has proposed an emerging role of GABA synthesis, reuptake, ionotropic and metabotropic receptor regulation, and interneuronal changes following sensitization to methamphetamine and/or amphetamine within the PFC. The aim of this review, therefore, is to synthesize research findings on changes to the GABAergic network following sensitization induced by amphetamines (i.e., amphetamine and/or methamphetamine) in the PFC. In addition to providing an overview of global PFC changes, we also provide evidence of regional specific inhibitory influences on sensitized circuitry, focusing on the prelimbic and orbitofrontal cortices. We propose a neural circuit through which inhibitory PFC GABA changes mediate sensitized disease states, focusing on the interaction between the prelimbic and orbitofrontal cortices with subcortical brain structures and the mesolimbic system. Methodological considerations and avenues for future research are also discussed.
Collapse
Affiliation(s)
- Travis A Wearne
- Department of Psychology, Macquarie University, Sydney, NSW, Australia; School of Psychology, University of New South Wales, Kensington, NSW, Australia
| | | |
Collapse
|
10
|
Γ-Aminobutyric acid in adult brain: an update. Behav Brain Res 2019; 376:112224. [DOI: 10.1016/j.bbr.2019.112224] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 09/09/2019] [Accepted: 09/09/2019] [Indexed: 01/21/2023]
|
11
|
Campbell RR, Domingo RD, Williams AR, Wroten MG, McGregor HA, Waltermire RS, Greentree DI, Goulding SP, Thompson AB, Lee KM, Quadir SG, Jimenez Chavez CL, Coelho MA, Gould AT, von Jonquieres G, Klugmann M, Worley PF, Kippin TE, Szumlinski KK. Increased Alcohol-Drinking Induced by Manipulations of mGlu5 Phosphorylation within the Bed Nucleus of the Stria Terminalis. J Neurosci 2019; 39:2745-2761. [PMID: 30737312 PMCID: PMC6445984 DOI: 10.1523/jneurosci.1909-18.2018] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 12/06/2018] [Accepted: 12/21/2018] [Indexed: 12/18/2022] Open
Abstract
The bed nucleus of the stria terminalis (BNST) is part of the limbic-hypothalamic system important for behavioral responses to stress, and glutamate transmission within this region has been implicated in the neurobiology of alcoholism. Herein, we used a combination of immunoblotting, neuropharmacological and transgenic procedures to investigate the role for metabotropic glutamate receptor 5 (mGlu5) signaling within the BNST in excessive drinking. We discovered that mGlu5 signaling in the BNST is linked to excessive alcohol consumption in a manner distinct from behavioral or neuropharmacological endophenotypes that have been previously implicated as triggers for heavy drinking. Our studies demonstrate that, in male mice, a history of chronic binge alcohol-drinking elevates BNST levels of the mGlu5-scaffolding protein Homer2 and activated extracellular signal-regulated kinase (ERK) in an adaptive response to limit alcohol consumption. Male and female transgenic mice expressing a point mutation of mGlu5 that cannot be phosphorylated by ERK exhibit excessive alcohol-drinking, despite greater behavioral signs of alcohol intoxication and reduced anxiety, and are insensitive to local manipulations of signaling in the BNST. These transgenic mice also show selective insensitivity to alcohol-aversion and increased novelty-seeking, which may be relevant to excessive drinking. Further, the insensitivity to alcohol-aversion exhibited by male mice can be mimicked by the local inhibition of ERK signaling within the BNST. Our findings elucidate a novel mGluR5-linked signaling state within BNST that plays a central and unanticipated role in excessive alcohol consumption.SIGNIFICANCE STATEMENT The bed nucleus of the stria terminalis (BNST) is part of the limbic-hypothalamic system important for behavioral responses to stress and alcohol, and glutamate transmission within BNST is implicated in the neurobiology of alcoholism. The present study provides evidence that a history of excessive alcohol drinking increases signaling through the metabotropic glutamate receptor 5 (mGlu5) receptor within the BNST in an adaptive response to limit alcohol consumption. In particular, disruption of mGlu5 phosphorylation by extracellular signal-regulated kinase within this brain region induces excessive alcohol-drinking, which reflects a selective insensitivity to the aversive properties of alcohol intoxication. These data indicate that a specific signaling state of mGlu5 within BNST plays a central and unanticipated role in excessive alcohol consumption.
Collapse
Affiliation(s)
- Rianne R Campbell
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Racquel D Domingo
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Amy R Williams
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Melissa G Wroten
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Hadley A McGregor
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Ryan S Waltermire
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Daniel I Greentree
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Scott P Goulding
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Andrew B Thompson
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Kaziya M Lee
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Sema G Quadir
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - C Leonardo Jimenez Chavez
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Michal A Coelho
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Adam T Gould
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Georg von Jonquieres
- Translational Neuroscience Facility, School of Medical Sciences, University of New South Wales, New South Wales 2052, Australia, and
| | - Matthias Klugmann
- Translational Neuroscience Facility, School of Medical Sciences, University of New South Wales, New South Wales 2052, Australia, and
| | - Paul F Worley
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Tod E Kippin
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - Karen K Szumlinski
- Department of Psychological and Brain Sciences, the Neuroscience Research Institute, Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California 93106-9660,
| |
Collapse
|
12
|
O’Connor MJ, Beebe LL, Deodato D, Ball RE, Page AT, VanLeuven AJ, Harris KT, Park S, Hariharan V, Lauderdale JD, Dore TM. Bypassing Glutamic Acid Decarboxylase 1 (Gad1) Induced Craniofacial Defects with a Photoactivatable Translation Blocker Morpholino. ACS Chem Neurosci 2019; 10:266-278. [PMID: 30200754 PMCID: PMC6337688 DOI: 10.1021/acschemneuro.8b00231] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
![]()
γ-Amino
butyric acid (GABA) mediated signaling is critical
in the central and enteric nervous systems, pancreas, lungs, and other
tissues. It is associated with many neurological disorders and craniofacial
development. Glutamic acid decarboxylase (GAD) synthesizes GABA from
glutamate, and knockdown of the gad1 gene results
in craniofacial defects that are lethal in zebrafish. To bypass this
and enable observation of the neurological defects resulting from
knocking down gad1 expression, a photoactivatable
morpholino oligonucleotide (MO) against gad1 was
prepared by cyclization with a photocleavable linker rendering the
MO inactive. The cyclized MO was stable in the dark and toward degradative
enzymes and was completely linearized upon brief exposure to 405 nm
light. In the course of investigating the function of the ccMOs in
zebrafish, we discovered that zebrafish possess paralogous gad1 genes, gad1a and gad1b. A gad1b MO injected at the 1–4 cell stage
caused severe morphological defects in head development, which could
be bypassed, enabling the fish to develop normally, if the fish were
injected with a photoactivatable, cyclized gad1b MO
and grown in the dark. At 1 day post fertilization (dpf), light activation
of the gad1b MO followed by observation at 3 and
7 dpf led to increased and abnormal electrophysiological brain activity
compared to wild type animals. The photocleavable linker can be used
to cyclize and inactivate any MO, and represents a general strategy
to parse the function of developmentally important genes in a spatiotemporal
manner.
Collapse
Affiliation(s)
- Matthew J. O’Connor
- New York University Abu Dhabi, PO Box 129188, Abu Dhabi, United Arab Emirates
| | - Lindsey L. Beebe
- Department of Genetics, University of Georgia, Athens, Georgia 30602, United States
| | - Davide Deodato
- New York University Abu Dhabi, PO Box 129188, Abu Dhabi, United Arab Emirates
| | - Rebecca E. Ball
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, United States
| | - A. Tyler Page
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, United States
| | - Ariel J. VanLeuven
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, United States
| | - Kyle T. Harris
- Department of Chemistry, University of Georgia, Athens, Georgia 30602 United States
| | - Sungdae Park
- Department of Genetics, University of Georgia, Athens, Georgia 30602, United States
| | - Vani Hariharan
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, United States
| | - James D. Lauderdale
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, United States
- Neuroscience
Division
of the Biomedical and Health Sciences Institute, Athens, Georgia 30602, United States
| | - Timothy M. Dore
- New York University Abu Dhabi, PO Box 129188, Abu Dhabi, United Arab Emirates
- Department of Chemistry, University of Georgia, Athens, Georgia 30602 United States
| |
Collapse
|
13
|
Prefrontal-Bed Nucleus Circuit Modulation of a Passive Coping Response Set. J Neurosci 2018; 39:1405-1419. [PMID: 30573644 DOI: 10.1523/jneurosci.1421-18.2018] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 11/16/2018] [Accepted: 12/12/2018] [Indexed: 12/29/2022] Open
Abstract
One of the challenges facing neuroscience entails localization of circuits and mechanisms accounting for how multiple features of stress responses are organized to promote survival during adverse experiences. The rodent medial prefrontal cortex (mPFC) is generally regarded as a key site for cognitive and affective information processing, and the anteroventral bed nuclei of the stria terminalis (avBST) integrates homeostatic information from a variety of sources, including the mPFC. Thus, we proposed that the mPFC is capable of generating multiple features (endocrine, behavioral) of adaptive responses via its influence over the avBST. To address this possibility, we first optogenetically inhibited input to avBST from the rostral prelimbic cortical region of mPFC and observed concurrent increases in immobility and hypothalamo-pituitary-adrenal (HPA) output in male rats during tail suspension, whereas photostimulation of this pathway decreased immobility during the same challenge. Anatomical tracing experiments confirmed projections from the rostral prelimbic subfield to separate populations of avBST neurons, and from these to HPA effector neurons in the paraventricular hypothalamic nucleus, and to aspects of the midbrain periaqueductal gray that coordinate passive defensive behaviors. Finally, stimulation and inhibition of the prelimbic-avBST pathway, respectively, decreased and increased passive coping in the shock-probe defensive burying test, without having any direct effect on active coping (burying) behavior. These results define a new neural substrate in the coordination of a response set that involves the gating of passive, rather than active, coping behaviors while restraining neuroendocrine activation to optimize adaptation during threat exposure.SIGNIFICANCE STATEMENT The circuits and mechanisms accounting for how multiple features of responses are organized to promote adaptation have yet to be elucidated. Our report identifies a prefrontal-bed nucleus pathway that organizes a response set capable of gating passive coping behaviors while concurrently restraining neuroendocrine activation during exposure to inescapable stressors. These data provide insight into the central organization of how multiple features of responses are integrated to promote adaptation during adverse experiences, and how disruption in one neural pathway may underlie a broad array of maladaptive responses in stress-related psychiatric disorders.
Collapse
|
14
|
Lee SJ, Sanchez-Watts G, Krieger JP, Pignalosa A, Norell PN, Cortella A, Pettersen KG, Vrdoljak D, Hayes MR, Kanoski SE, Langhans W, Watts AG. Loss of dorsomedial hypothalamic GLP-1 signaling reduces BAT thermogenesis and increases adiposity. Mol Metab 2018; 11:33-46. [PMID: 29650350 PMCID: PMC6001878 DOI: 10.1016/j.molmet.2018.03.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/09/2018] [Accepted: 03/14/2018] [Indexed: 12/15/2022] Open
Abstract
Objective Glucagon-like peptide-1 (GLP-1) neurons in the hindbrain densely innervate the dorsomedial hypothalamus (DMH), a nucleus strongly implicated in body weight regulation and the sympathetic control of brown adipose tissue (BAT) thermogenesis. Therefore, DMH GLP-1 receptors (GLP-1R) are well placed to regulate energy balance by controlling sympathetic outflow and BAT function. Methods We investigate this possibility in adult male rats by using direct administration of GLP-1 (0.5 ug) into the DMH, knocking down DMH GLP-1R mRNA with viral-mediated RNA interference, and by examining the neurochemical phenotype of GLP-1R expressing cells in the DMH using in situ hybridization. Results GLP-1 administered into the DMH increased BAT thermogenesis and hepatic triglyceride (TG) mobilization. On the other hand, Glp1r knockdown (KD) in the DMH increased body weight gain and adiposity, with a concomitant reduction in energy expenditure (EE), BAT temperature, and uncoupling protein 1 (UCP1) expression. Moreover, DMH Glp1r KD induced hepatic steatosis, increased plasma TG, and elevated liver specific de-novo lipogenesis, effects that collectively contributed to insulin resistance. Interestingly, DMH Glp1r KD increased neuropeptide Y (NPY) mRNA expression in the DMH. GLP-1R mRNA in the DMH, however, was found in GABAergic not NPY neurons, consistent with a GLP-1R-dependent inhibition of NPY neurons that is mediated by local GABAergic neurons. Finally, DMH Glp1r KD attenuated the anorexigenic effects of the GLP-1R agonist exendin-4, highlighting an important role of DMH GLP-1R signaling in GLP-1-based therapies. Conclusions Collectively, our data show that DMH GLP-1R signaling plays a key role for BAT thermogenesis and adiposity. DMH GLP-1R stimulation acutely increases BAT thermogenesis. DMH GLP-1R mRNA knockdown decreases EE and BAT thermogenesis. DMH GLP-1R mRNA knockdown impairs lipid and glucose metabolism. Reduced DMH GLP-1R signaling blunts the anorexigenic responses to Ex-4. DMH GLP-1R signaling indirectly regulates NPY gene expression.
Collapse
Affiliation(s)
- Shin J Lee
- Physiology and Behavior Laboratory, ETH Zürich, 8603 Schwerzenbach, Switzerland.
| | - Graciela Sanchez-Watts
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | | | - Angelica Pignalosa
- Physiology and Behavior Laboratory, ETH Zürich, 8603 Schwerzenbach, Switzerland
| | - Puck N Norell
- Physiology and Behavior Laboratory, ETH Zürich, 8603 Schwerzenbach, Switzerland
| | - Alyssa Cortella
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Klaus G Pettersen
- Physiology and Behavior Laboratory, ETH Zürich, 8603 Schwerzenbach, Switzerland
| | - Dubravka Vrdoljak
- Physiology and Behavior Laboratory, ETH Zürich, 8603 Schwerzenbach, Switzerland
| | - Matthew R Hayes
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Scott E Kanoski
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Wolfgang Langhans
- Physiology and Behavior Laboratory, ETH Zürich, 8603 Schwerzenbach, Switzerland
| | - Alan G Watts
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| |
Collapse
|
15
|
Wang X, Liu C, Wang X, Gao F, Zhan RZ. Density and neurochemical profiles of neuronal nitric oxide synthase-expressing interneuron in the mouse basolateral amygdala. Brain Res 2017; 1663:106-113. [DOI: 10.1016/j.brainres.2017.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Revised: 12/24/2016] [Accepted: 02/12/2017] [Indexed: 01/28/2023]
|
16
|
Vranjkovic O, Pina M, Kash TL, Winder DG. The bed nucleus of the stria terminalis in drug-associated behavior and affect: A circuit-based perspective. Neuropharmacology 2017; 122:100-106. [PMID: 28351600 DOI: 10.1016/j.neuropharm.2017.03.028] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/21/2017] [Accepted: 03/23/2017] [Indexed: 10/19/2022]
Abstract
The bed nucleus of the stria terminalis was first described nearly a century ago and has since emerged as a region central to motivated behavior and affective states. The last several decades have firmly established a role for the BNST in drug-associated behavior and implicated this region in addiction-related processes. Whereas past approaches used to characterize the BNST have focused on a more general role of this region and its subnuclei in behavior, more recent work has begun to reveal its elaborate circuitry and cellular components. Such recent developments are largely owed to methodological advances, which have made possible efforts previously deemed intractable, such as tracing of long-range cell-type specific projections and identifying functional efferent and afferent connections. In this review, we integrate earlier foundational work with more recent and advanced studies to construct a broad overview of the molecular neurocircuitry of the BNST in drug-associated behavior and affect. This article is part of the Special Issue entitled "Alcoholism".
Collapse
Affiliation(s)
- Oliver Vranjkovic
- Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, USA
| | - Melanie Pina
- Bowles Center for Alcohol Studies, Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, USA
| | - Thomas L Kash
- Bowles Center for Alcohol Studies, Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, USA
| | - Danny G Winder
- Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, USA; Department of Psychiatry, Vanderbilt University School of Medicine, USA; Department of Pharmacology, Vanderbilt University School of Medicine, USA; Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| |
Collapse
|
17
|
Growth hormone biases amygdala network activation after fear learning. Transl Psychiatry 2016; 6:e960. [PMID: 27898076 PMCID: PMC5290350 DOI: 10.1038/tp.2016.203] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 07/07/2016] [Accepted: 07/18/2016] [Indexed: 01/27/2023] Open
Abstract
Prolonged stress exposure is a risk factor for developing posttraumatic stress disorder, a disorder characterized by the 'over-encoding' of a traumatic experience. A potential mechanism by which this occurs is through upregulation of growth hormone (GH) in the amygdala. Here we test the hypotheses that GH promotes the over-encoding of fearful memories by increasing the number of neurons activated during memory encoding and biasing the allocation of neuronal activation, one aspect of the process by which neurons compete to encode memories, to favor neurons that have stronger inputs. Viral overexpression of GH in the amygdala increased the number of amygdala cells activated by fear memory formation. GH-overexpressing cells were especially biased to express the immediate early gene c-Fos after fear conditioning, revealing strong autocrine actions of GH in the amygdala. In addition, we observed dramatically enhanced dendritic spine density in GH-overexpressing neurons. These data elucidate a previously unrecognized autocrine role for GH in the regulation of amygdala neuron function and identify specific mechanisms by which chronic stress, by enhancing GH in the amygdala, may predispose an individual to excessive fear memory formation.
Collapse
|
18
|
Development of putative inhibitory neurons in the embryonic and postnatal mouse superficial spinal dorsal horn. Brain Struct Funct 2016; 222:2157-2171. [PMID: 27783222 DOI: 10.1007/s00429-016-1331-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 10/20/2016] [Indexed: 10/20/2022]
Abstract
The superficial spinal dorsal horn is the first relay station of pain processing. It is also widely accepted that spinal synaptic processing to control the modality and intensity of pain signals transmitted to higher brain centers is primarily defined by inhibitory neurons in the superficial spinal dorsal horn. Earlier studies suggest that the construction of pain processing spinal neural circuits including the GABAergic components should be completed by birth, although major chemical refinements may occur postnatally. Because of their utmost importance in pain processing, we intended to provide a detailed knowledge concerning the development of GABAergic neurons in the superficial spinal dorsal horn, which is now missing from the literature. Thus, we studied the developmental changes in the distribution of neurons expressing GABAergic markers like Pax2, GAD65 and GAD67 in the superficial spinal dorsal horn of wild type as well as GAD65-GFP and GAD67-GFP transgenic mice from embryonic day 11.5 (E11.5) till postnatal day 14 (P14). We found that GABAergic neurons populate the superficial spinal dorsal horn from the beginning of its delineation at E14.5. We also showed that the numbers of GABAergic neurons in the superficial spinal dorsal horn continuously increase till E17.5, but there is a prominent decline in their numbers during the first two postnatal weeks. Our results indicate that the developmental process leading to the delineation of the inhibitory and excitatory cellular assemblies of pain processing neural circuits in the superficial spinal dorsal horn of mice is not completed by birth, but it continues postnatally.
Collapse
|
19
|
Liao C, Han Q, Ma Y, Su B. Age-related gene expression change of GABAergic system in visual cortex of rhesus macaque. Gene 2016; 590:227-33. [PMID: 27196061 DOI: 10.1016/j.gene.2016.05.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 05/03/2016] [Accepted: 05/08/2016] [Indexed: 01/31/2023]
Abstract
Degradation of visual function is a common phenomenon during aging and likely mediated by change in the impaired central visual pathway. Treatment with GABA or its agonist could recover the ability of visual neurons in the primary visual cortex of senescent macaques. However, little is known about how GABAergic system change is related to the aged degradation of visual function in nonhuman primate. With the use of quantitative PCR method, we measured the expression change of 24 GABA related genes in the primary visual cortex (Brodmann's 17) of different age groups. In this study, both of mRNA and protein of glutamic acid decarboxylase (GAD65) were measured by real-time RT-PCR and Western blot, respectively. Results revealed that the level of GAD65 message was not significantly altered, but the proteins were significantly decreased in the aged monkey. As GAD65 plays an important role in GABA synthesis, the down-regulation of GAD65 protein was likely the key factor leading to the observed GABA reduction in the primary visual cortex of the aged macaques. In addition, 7 of 14 GABA receptor genes were up-regulated and one GABA receptor gene was significantly reduced during aging process even after Banjamini correction for multiple comparisons (P<0.05). These results suggested that the dysregulation of GAD65 protein might contribute to some age-related neural visual dysfunctions and most of GABA receptor genes induce a clear indication of compensatory effect for the reduced GABA release in the healthy aged monkey cortex.
Collapse
Affiliation(s)
- Chenghong Liao
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, 570228, China; Laboratory of Tropical Veterinary Medicine and Vector Biology, College of Agriculture, Hainan University, Haikou, 570228, China
| | - Qian Han
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, 570228, China; Laboratory of Tropical Veterinary Medicine and Vector Biology, College of Agriculture, Hainan University, Haikou, 570228, China
| | - Yuanye Ma
- Laboratory of the Primate Model for Brain Diseases and Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming 650223, China; State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan, China
| | - Bing Su
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.
| |
Collapse
|
20
|
Glutamic acid decarboxylase isoform distribution in transgenic mouse septum: an anti-GFP immunofluorescence study. Anat Sci Int 2015; 91:398-406. [PMID: 26643381 DOI: 10.1007/s12565-015-0316-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 11/08/2015] [Indexed: 10/22/2022]
Abstract
The septum is a basal forebrain region located between the lateral ventricles in rodents. It consists of lateral and medial divisions. Medial septal projections regulate hippocampal theta rhythm whereas lateral septal projections are involved in processes such as affective functions, memory formation, and behavioral responses. Gamma-aminobutyric acidergic neurons of the septal region possess the 65 and 67 isoforms of the enzyme glutamic acid decarboxylase. Although data on the glutamic acid decarboxylase isoform distribution in the septal region generally appears to indicate glutamic acid decarboxylase 67 dominance, different studies have given inconsistent results in this regard. The aim of this study was therefore to obtain information on the distributions of both of these glutamic acid decarboxylase isoforms in the septal region in transgenic mice. Two animal groups of glutamic acid decarboxylase-green fluorescent protein knock-in transgenic mice were utilized in the experiment. Brain sections from the region were taken for anti-green fluorescent protein immunohistochemistry in order to obtain estimated quantitative data on the number of gamma-aminobutyric acidergic neurons. Following the immunohistochemical procedures, the mean numbers of labeled cells in the lateral and medial septal nuclei were obtained for the two isoform groups. Statistical analysis yielded significant results which indicated that the 65 isoform of glutamic acid decarboxylase predominates in both lateral and medial septal nuclei (unpaired two-tailed t-test p < 0.0001 for LS, p < 0.01 for MS). This study is the first to reveal the dominance of glutamic acid decarboxylase isoform 65 in the septal region in glutamic acid decarboxylase-green fluorescent protein transgenic mice.
Collapse
|
21
|
Kalló I, Molnár CS, Szöke S, Fekete C, Hrabovszky E, Liposits Z. Area-specific analysis of the distribution of hypothalamic neurons projecting to the rat ventral tegmental area, with special reference to the GABAergic and glutamatergic efferents. Front Neuroanat 2015; 9:112. [PMID: 26388742 PMCID: PMC4559648 DOI: 10.3389/fnana.2015.00112] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 07/30/2015] [Indexed: 12/22/2022] Open
Abstract
The ventral tegmental area (VTA) is a main regulator of reward and integrates a wide scale of hormonal and neuronal information. Feeding-, energy expenditure-, stress, adaptation- and reproduction-related hypothalamic signals are processed in the VTA and influence the reward processes. However, the neuroanatomical origin and chemical phenotype of neurons mediating these signals to the VTA have not been fully characterized. In this study we have systematically mapped hypothalamic neurons that project to the VTA using the retrograde tracer Choleratoxin B subunit (CTB) and analyzed their putative gamma-aminobutyric acid (GABA) and/or glutamate character with in situ hybridization in male rats. 23.93 ± 3.91% of hypothalamic neurons projecting to the VTA was found in preoptic and 76.27 ± 4.88% in anterior, tuberal and mammillary hypothalamic regions. Nearly half of the retrogradely-labeled neurons in the preoptic, and more than one third in the anterior, tuberal and mammillary hypothalamus appeared in medially located regions. The analyses of vesicular glutamate transporter 2 (VGLUT2) and glutamate decarboxylase 65 (GAD65) mRNA expression revealed both amino acid markers in different subsets of retrogradely-labeled hypothalamic neurons, typically with the predominance of the glutamatergic marker VGLUT2. About one tenth of CTB-IR neurons were GAD65-positive even in hypothalamic nuclei expressing primarily VGLUT2. Some regions were populated mostly by GAD65 mRNA-containing retrogradely-labeled neurons. These included the perifornical part of the lateral hypothalamus where 58.63 ± 19.04% of CTB-IR neurons were GABAergic. These results indicate that both the medial and lateral nuclear compartments of the hypothalamus provide substantial input to the VTA. Furthermore, colocalization studies revealed that these projections not only use glutamate but also GABA for neurotransmission. These GABAergic afferents may underlie important inhibitory mechanism to fine-tune the reward value of specific signals in the VTA.
Collapse
Affiliation(s)
- Imre Kalló
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary ; Faculty of Information Technology and Bionics, Pázmány Péter Catholic University Budapest, Hungary
| | - Csilla S Molnár
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Sarolta Szöke
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Csaba Fekete
- Laboratory of Integrative Neuroendocrinology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary ; Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tupper Research Institute, Tufts Medical Center Boston, MA, USA
| | - Erik Hrabovszky
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Zsolt Liposits
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary ; Faculty of Information Technology and Bionics, Pázmány Péter Catholic University Budapest, Hungary
| |
Collapse
|
22
|
Besser S, Sicker M, Marx G, Winkler U, Eulenburg V, Hülsmann S, Hirrlinger J. A Transgenic Mouse Line Expressing the Red Fluorescent Protein tdTomato in GABAergic Neurons. PLoS One 2015; 10:e0129934. [PMID: 26076353 PMCID: PMC4468179 DOI: 10.1371/journal.pone.0129934] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 05/13/2015] [Indexed: 12/25/2022] Open
Abstract
GABAergic inhibitory neurons are a large population of neurons in the central nervous system (CNS) of mammals and crucially contribute to the function of the circuitry of the brain. To identify specific cell types and investigate their functions labelling of cell populations by transgenic expression of fluorescent proteins is a powerful approach. While a number of mouse lines expressing the green fluorescent protein (GFP) in different subpopulations of GABAergic cells are available, GFP expressing mouse lines are not suitable for either crossbreeding to other mouse lines expressing GFP in other cell types or for Ca2+-imaging using the superior green Ca2+-indicator dyes. Therefore, we have generated a novel transgenic mouse line expressing the red fluorescent protein tdTomato in GABAergic neurons using a bacterial artificial chromosome based strategy and inserting the tdTomato open reading frame at the start codon within exon 1 of the GAD2 gene encoding glutamic acid decarboxylase 65 (GAD65). TdTomato expression was observed in all expected brain regions; however, the fluorescence intensity was highest in the olfactory bulb and the striatum. Robust expression was also observed in cortical and hippocampal neurons, Purkinje cells in the cerebellum, amacrine cells in the retina as well as in cells migrating along the rostral migratory stream. In cortex, hippocampus, olfactory bulb and brainstem, 80% to 90% of neurons expressing endogenous GAD65 also expressed the fluorescent protein. Moreover, almost all tdTomato-expressing cells coexpressed GAD65, indicating that indeed only GABAergic neurons are labelled by tdTomato expression. This mouse line with its unique spectral properties for labelling GABAergic neurons will therefore be a valuable new tool for research addressing this fascinating cell type.
Collapse
Affiliation(s)
- Stefanie Besser
- Carl-Ludwig-Institute for Physiology, University of Leipzig, Leipzig, Germany
| | - Marit Sicker
- Carl-Ludwig-Institute for Physiology, University of Leipzig, Leipzig, Germany
| | - Grit Marx
- Carl-Ludwig-Institute for Physiology, University of Leipzig, Leipzig, Germany
| | - Ulrike Winkler
- Carl-Ludwig-Institute for Physiology, University of Leipzig, Leipzig, Germany
| | - Volker Eulenburg
- Institute for Biochemistry and Molecular Medicine, University of Erlangen, Erlangen, Germany
| | - Swen Hülsmann
- Laboratory for Experimental Neuroanesthesiology, Clinic for Anesthesiology, University Hospital Göttingen, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Johannes Hirrlinger
- Carl-Ludwig-Institute for Physiology, University of Leipzig, Leipzig, Germany
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| |
Collapse
|
23
|
Brown RE, McKenna JT. Turning a Negative into a Positive: Ascending GABAergic Control of Cortical Activation and Arousal. Front Neurol 2015; 6:135. [PMID: 26124745 PMCID: PMC4463930 DOI: 10.3389/fneur.2015.00135] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 05/28/2015] [Indexed: 01/01/2023] Open
Abstract
Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain. Recent technological advances have illuminated the role of GABAergic neurons in control of cortical arousal and sleep. Sleep-promoting GABAergic neurons in the preoptic hypothalamus are well-known. Less well-appreciated are GABAergic projection neurons in the brainstem, midbrain, hypothalamus, and basal forebrain, which paradoxically promote arousal and fast electroencephalographic (EEG) rhythms. Thus, GABA is not purely a sleep-promoting neurotransmitter. GABAergic projection neurons in the brainstem nucleus incertus and ventral tegmental nucleus of Gudden promote theta (4-8 Hz) rhythms. Ventral tegmental area GABAergic neurons, neighboring midbrain dopamine neurons, project to the frontal cortex and nucleus accumbens. They discharge faster during cortical arousal and regulate reward. Thalamic reticular nucleus GABAergic neurons initiate sleep spindles in non-REM sleep. In addition, however, during wakefulness, they tonically regulate the activity of thalamocortical neurons. Other GABAergic inputs to the thalamus arising in the globus pallidus pars interna, substantia nigra pars reticulata, zona incerta, and basal forebrain regulate motor activity, arousal, attention, and sensory transmission. Several subpopulations of cortically projecting GABAergic neurons in the basal forebrain project to the thalamus and neocortex and preferentially promote cortical gamma-band (30-80 Hz) activity and wakefulness. Unlike sleep-active GABAergic neurons, these ascending GABAergic neurons are fast-firing neurons which disinhibit and synchronize the activity of their forebrain targets, promoting the fast EEG rhythms typical of conscious states. They are prominent targets of GABAergic hypnotic agents. Understanding the properties of ascending GABAergic neurons may lead to novel treatments for diseases involving disorders of cortical activation and wakefulness.
Collapse
Affiliation(s)
- Ritchie E Brown
- Laboratory of Neuroscience, Department of Psychiatry, VA Boston Healthcare System, Harvard Medical School , Brockton, MA , USA
| | - James T McKenna
- Laboratory of Neuroscience, Department of Psychiatry, VA Boston Healthcare System, Harvard Medical School , Brockton, MA , USA
| |
Collapse
|
24
|
A premammillary lateral hypothalamic nuclear complex responds to hedonic but not aversive tastes in the male rat. Brain Struct Funct 2015; 221:2183-208. [PMID: 25863939 DOI: 10.1007/s00429-015-1038-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 04/01/2015] [Indexed: 12/18/2022]
Abstract
The lateral hypothalamic area (LHA) has two major roles: arousal/waking and food intake controls. Here, it is shown that a premammillary part of the LHA is neurochemically and cytoarchitectonically distinct from the tuberal LHA in male rats. This part contains nuclear masses, namely the parasubthalamic nucleus and the calbindin nucleus, involved in pathways that predict its participation in the control of food intake. Analyzing c-Fos expression in experiments related to feeding behavior, this region responded specifically to the ingestion of palatable nutriments.
Collapse
|
25
|
Taylor SR, Badurek S, Dileone RJ, Nashmi R, Minichiello L, Picciotto MR. GABAergic and glutamatergic efferents of the mouse ventral tegmental area. J Comp Neurol 2015; 522:3308-34. [PMID: 24715505 DOI: 10.1002/cne.23603] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 04/02/2014] [Accepted: 04/03/2014] [Indexed: 12/11/2022]
Abstract
The role of dopaminergic (DA) projections from the ventral tegmental area (VTA) in appetitive and rewarding behavior has been widely studied, but the VTA also has documented DA-independent functions. Several drugs of abuse, act on VTA GABAergic neurons, and most studies have focused on local inhibitory connections. Relatively little is known about VTA GABA projection neurons and their connections to brain sites outside the VTA. This study employed viral-vector-mediated cell-type-specific anterograde tracing, classical retrograde tracing, and immunohistochemistry to characterize VTA GABA efferents throughout the brain. We found that VTA GABA neurons project widely to forebrain and brainstem targets, including the ventral pallidum, lateral and magnocellular preoptic nuclei, lateral hypothalamus, and lateral habenula. Minor projections also go to central amygdala, mediodorsal thalamus, dorsal raphe, and deep mesencephalic nuclei, and sparse projections go to prefrontal cortical regions and to nucleus accumbens shell and core. These projections differ from the major VTA DA target regions. Retrograde tracing studies confirmed results from the anterograde experiments and differences in projections from VTA subnuclei. Retrogradely labeled GABA neurons were not numerous, and most non-tyrosine hydroxylase/retrogradely labeled cells lacked GABAergic markers. Many non-TH/retrogradely labeled cells projecting to several areas expressed VGluT2. VTA GABA and glutamate neurons project throughout the brain, most prominently to regions with reciprocal connections to the VTA. These data indicate that VTA GABA and glutamate neurons may have more DA-independent functions than previously recognized.
Collapse
Affiliation(s)
- Seth R Taylor
- Interdepartmental Neuroscience Program, Yale University, New Haven, Connecticut, 06519
| | | | | | | | | | | |
Collapse
|
26
|
Miyamoto Y, Fukuda T. Immunohistochemical study on the neuronal diversity and three-dimensional organization of the mouse entopeduncular nucleus. Neurosci Res 2015; 94:37-49. [PMID: 25722090 DOI: 10.1016/j.neures.2015.02.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 02/13/2015] [Accepted: 02/14/2015] [Indexed: 10/23/2022]
Abstract
The entopeduncular nucleus (EPN) is one of the major output nuclei of the basal ganglia in rodents. Previous studies have divided it into rostral and caudal halves, with the former containing somatostatin (SOM)-immunoreactive neurons and the latter dominated by parvalbumin (PV)-containing neurons, respectively. However, it is unclear whether this simple rostrocaudal segmentation is appropriate, and the possibility of the existence of other neuronal populations remains to be investigated. In this study the cytoarchitecture of the mouse EPN was analyzed immunohistochemically. Substance P (SP)-immunoreactivity determined the extent of the EPN, which was 800 μm-long along the rostrocaudal axis. PV-positive neurons were concentrated in the caudal two-thirds of this range. PV-negative neurons were abundant in the rostral half but were further located caudally around the PV neuron-rich core. PV(+)/SOM(-) and PV(-)/SOM(+) neurons constituted 28.6% and 45.7% of EPN neurons, respectively, whereas the remaining population (25.7%) exhibited neither immunoreactivity. Eleven percent of EPN neurons lacked immunoreactivity for glutamic acid decarboxylase, indicating their non-GABAergic nature. Three-dimensional reconstruction revealed that PV-rich/SP-poor core was surrounded by PV-poor/SP-rich shell region. Therefore, presumptive thalamus-targeting PV neurons are outnumbered by other populations, and the regional heterogeneity shown here might be related to functionally distinct pathways through the basal ganglia.
Collapse
Affiliation(s)
- Yuta Miyamoto
- Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, Japan
| | - Takaichi Fukuda
- Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, Japan.
| |
Collapse
|
27
|
Lower glutamic acid decarboxylase 65-kDa isoform messenger RNA and protein levels in the prefrontal cortex in schizoaffective disorder but not schizophrenia. Biol Psychiatry 2015; 77:167-76. [PMID: 24993056 PMCID: PMC4247819 DOI: 10.1016/j.biopsych.2014.05.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 05/13/2014] [Accepted: 05/21/2014] [Indexed: 01/27/2023]
Abstract
BACKGROUND Altered gamma-aminobutyric acid (GABA) signaling in the prefrontal cortex (PFC) has been associated with cognitive dysfunction in patients with schizophrenia and schizoaffective disorder. Levels of the GABA-synthesizing enzyme glutamic acid decarboxylase 67-kDa isoform (GAD67) in the PFC have been consistently reported to be lower in patients with these disorders, but the status of the second GABA-synthesizing enzyme, glutamic acid decarboxylase 65-kDa isoform (GAD65), remains unclear. METHODS GAD65 messenger RNA (mRNA) levels were quantified in PFC area 9 by quantitative polymerase chain reaction from 62 subjects with schizophrenia or schizoaffective disorder and 62 matched healthy comparison subjects. In a subset of subject pairs, GAD65 relative protein levels were quantified by confocal immunofluorescence microscopy. RESULTS Mean GAD65 mRNA levels were 13.6% lower in subjects with schizoaffective disorder but did not differ in subjects with schizophrenia relative to their matched healthy comparison subjects. In the subjects with schizoaffective disorder, mean GAD65 protein levels were 19.4% lower and were correlated with GAD65 mRNA levels. Lower GAD65 mRNA and protein levels within subjects with schizoaffective disorder were not attributable to factors commonly comorbid with the diagnosis. CONCLUSIONS In concert with previous studies, these findings suggest that schizoaffective disorder is associated with lower levels of both GAD65 and GAD67 mRNA and protein in the PFC, whereas subjects with schizophrenia have lower mean levels of only GAD67 mRNA and protein. Because cognitive function is generally better preserved in patients with schizoaffective disorder relative to patients with schizophrenia, these findings may support an interpretation that GAD65 downregulation provides a homeostatic response complementary to GAD67 downregulation that serves to reduce inhibition in the face of lower PFC network activity.
Collapse
|
28
|
Wang L, Ennis M, Szabó G, Armstrong WE. Characteristics of GABAergic and cholinergic neurons in perinuclear zone of mouse supraoptic nucleus. J Neurophysiol 2014; 113:754-67. [PMID: 25376783 DOI: 10.1152/jn.00561.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The perinuclear zone (PNZ) of the supraoptic nucleus (SON) contains some GABAergic and cholinergic neurons thought to innervate the SON proper. In mice expressing enhanced green fluorescent protein (eGFP) in association with glutamate decarboxylase (GAD)65 we found an abundance of GAD65-eGFP neurons in the PNZ, whereas in mice expressing GAD67-eGFP, there were few labeled PNZ neurons. In mice expressing choline acetyltransferase (ChAT)-eGFP, large, brightly fluorescent and small, dimly fluorescent ChAT-eGFP neurons were present in the PNZ. The small ChAT-eGFP and GAD65-eGFP neurons exhibited a low-threshold depolarizing potential consistent with a low-threshold spike, with little transient outward rectification. Large ChAT-eGFP neurons exhibited strong transient outward rectification and a large hyperpolarizing spike afterpotential, very similar to that of magnocellular vasopressin and oxytocin neurons. Thus the large soma and transient outward rectification of large ChAT-eGFP neurons suggest that these neurons would be difficult to distinguish from magnocellular SON neurons in dissociated preparations by these criteria. Large, but not small, ChAT-eGFP neurons were immunostained with ChAT antibody (AB144p). Reconstructed neurons revealed a few processes encroaching near and passing through the SON from all types but no clear evidence of a terminal axon arbor. Large ChAT-eGFP neurons were usually oriented vertically and had four or five dendrites with multiple branches and an axon with many collaterals and local arborizations. Small ChAT-eGFP neurons had a more restricted dendritic tree compared with parvocellular GAD65 neurons, the latter of which had long thin processes oriented mediolaterally. Thus many of the characteristics found previously in unidentified, small PNZ neurons are also found in identified GABAergic neurons and in a population of smaller ChAT-eGFP neurons.
Collapse
Affiliation(s)
- Lie Wang
- Department of Anatomy and Neurobiology and Neuroscience Institute, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Matthew Ennis
- Department of Anatomy and Neurobiology and Neuroscience Institute, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Gábor Szabó
- Department of Gene Technology and Developmental Biology, Institute of Experimental Medicine, Budapest, Hungary
| | - William E Armstrong
- Department of Anatomy and Neurobiology and Neuroscience Institute, University of Tennessee Health Science Center, Memphis, Tennessee; and
| |
Collapse
|
29
|
Trifonov S, Yamashita Y, Kase M, Maruyama M, Sugimoto T. Glutamic acid decarboxylase 1 alternative splicing isoforms: characterization, expression and quantification in the mouse brain. BMC Neurosci 2014; 15:114. [PMID: 25322942 PMCID: PMC4295415 DOI: 10.1186/1471-2202-15-114] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/25/2014] [Indexed: 11/24/2022] Open
Abstract
Background GABA has important functions in brain plasticity related processes like memory, learning, locomotion and during the development of the nervous system. It is synthesized by the glutamic acid decarboxylase (GAD). There are two isoforms of GAD, GAD1 and GAD2, which are encoded by different genes. During embryonic development the transcription of GAD1 mRNA is regulated by alternative splicing and several alternative transcripts were distinguished in human, mouse and rat. Despite the fact that the structure of GAD1 gene has been extensively studied, knowledge of its exact structural organization, alternative promoter usage and splicing have remained incomplete. Results In the present study we report the identification and characterization of novel GAD1 splicing isoforms (GenBank: KM102984, KM102985) by analyzing genomic and mRNA sequence data using bioinformatics, cloning and sequencing. Ten mRNA isoforms are generated from GAD1 gene locus by the combined actions of utilizing different promoters and alternative splicing of the coding exons. Using RT-PCR we found that GAD1 isoforms share similar pattern of expression in different mouse tissues and are expressed early during development. Quantitative RT-PCR was used to investigate the expression of GAD1 isoforms and GAD2 in olfactory bulb, cortex, medial and lateral striatum, hippocampus and cerebellum of adult mouse. Olfactory bulb showed the highest expression of GAD1 transcripts. Isoforms 1/2 are the most abundant forms. Their expression is significantly higher in the lateral compared to the medial striatum. Isoforms 3/4, 5/6, 7/8 and 9/10 are barely detectable in all investigated regions except of the high expression in olfactory bulb. When comparing GAD1 expression with GAD2 we found that Isoforms 1/2 are the predominant isoforms. In situ hybridization confirmed the predominant expression of Isoforms 7/8 and 9/10 in the olfactory bulb and revealed their weak expression in hippocampus, cerebellum and some other areas known to express GAD1. Conclusions Generation of ten splicing isoforms of GAD1 was described including two so far uncharacterized transcripts. GAD1 splicing isoforms producing the shorter, enzymatically inactive GAD25 protein are expressed at very low level in adult mouse brain except in the olfactory bulb that is associated with neurogenesis and synaptic plasticity even during adulthood. Electronic supplementary material The online version of this article (doi:10.1186/1471-2202-15-114) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
| | | | | | | | - Tetsuo Sugimoto
- Department of Anatomy and Brain Science, Kansai Medical University, Hirakata, Osaka 573-1010, Japan.
| |
Collapse
|
30
|
Soussi R, Boulland JL, Bassot E, Bras H, Coulon P, Chaudhry FA, Storm-Mathisen J, Ferhat L, Esclapez M. Reorganization of supramammillary-hippocampal pathways in the rat pilocarpine model of temporal lobe epilepsy: evidence for axon terminal sprouting. Brain Struct Funct 2014; 220:2449-68. [PMID: 24889162 PMCID: PMC4481331 DOI: 10.1007/s00429-014-0800-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 05/14/2014] [Indexed: 01/11/2023]
Abstract
In mesial temporal lobe epilepsy (MTLE), spontaneous seizures likely originate from a multi-structural epileptogenic zone, including several regions of the limbic system connected to the hippocampal formation. In this study, we investigate the structural connectivity between the supramammillary nucleus (SuM) and the dentate gyrus (DG) in the model of MTLE induced by pilocarpine in the rat. This hypothalamic nucleus, which provides major extracortical projections to the hippocampal formation, plays a key role in the regulation of several hippocampus-dependent activities, including theta rhythms, memory function and emotional behavior, such as stress and anxiety, functions that are known to be altered in MTLE. Our findings demonstrate a marked reorganization of DG afferents originating from the SuM in pilocarpine-treated rats. This reorganization, which starts during the latent period, is massive when animals become epileptic and continue to evolve during epilepsy. It is characterized by an aberrant distribution and an increased number of axon terminals from neurons of both lateral and medial regions of the SuM, invading the entire inner molecular layer of the DG. This reorganization, which reflects an axon terminal sprouting from SuM neurons, could contribute to trigger spontaneous seizures within an altered hippocampal intrinsic circuitry.
Collapse
Affiliation(s)
- Rabia Soussi
- INSERM, UMR 1106, Institut de Neurosciences des Systèmes - INS, 13385, Marseille, France
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Rodríguez-Molina V, Patiño J, Vargas Y, Sánchez-Jaramillo E, Joseph-Bravo P, Charli JL. TRH regulates action potential shape in cerebral cortex pyramidal neurons. Brain Res 2014; 1571:1-11. [PMID: 24842001 DOI: 10.1016/j.brainres.2014.05.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 05/03/2014] [Accepted: 05/08/2014] [Indexed: 11/28/2022]
Abstract
Thyrotropin releasing hormone (TRH) is a neuropeptide with a wide neural distribution and a variety of functions. It modulates neuronal electrophysiological properties, including resting membrane potential, as well as excitatory postsynaptic potential and spike frequencies. We explored, with whole-cell patch clamp, TRH effect on action potential shape in pyramidal neurons of the sensorimotor cortex. TRH reduced spike and after hyperpolarization amplitudes, and increased spike half-width. The effect varied with dose, time and cortical layer. In layer V, 0.5µM of TRH induced a small increase in spike half-width, while 1 and 5µM induced a strong but transient change in spike half-width, and amplitude; after hyperpolarization amplitude was modified at 5µM of TRH. Cortical layers III and VI neurons responded intensely to 0.5µM TRH; layer II neurons response was small. The effect of 1µM TRH on action potential shape in layer V neurons was blocked by G-protein inhibition. Inhibition of the activity of the TRH-degrading enzyme pyroglutamyl peptidase II (PPII) reproduced the effect of TRH, with enhanced spike half-width. Many cortical PPII mRNA+ cells were VGLUT1 mRNA+, and some GAD mRNA+. These data show that TRH regulates action potential shape in pyramidal cortical neurons, and are consistent with the hypothesis that PPII controls its action in this region.
Collapse
Affiliation(s)
- Víctor Rodríguez-Molina
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), AP 70250, México, D.F. 04510, México; Facultad de Medicina, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México
| | - Javier Patiño
- Facultad de Medicina, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México
| | - Yamili Vargas
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Ave. Universidad 2001, Chamilpa, Cuernavaca, Morelos 62210, México
| | - Edith Sánchez-Jaramillo
- Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría, Ramón de la Fuente Muñíz, México D.F., México
| | - Patricia Joseph-Bravo
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Ave. Universidad 2001, Chamilpa, Cuernavaca, Morelos 62210, México
| | - Jean-Louis Charli
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Ave. Universidad 2001, Chamilpa, Cuernavaca, Morelos 62210, México.
| |
Collapse
|
32
|
Ma J, Yao XH, Fu Y, Yu YC. Development of Layer 1 Neurons in the Mouse Neocortex. Cereb Cortex 2014; 24:2604-18. [DOI: 10.1093/cercor/bht114] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
|
33
|
Tritsch NX, Oh WJ, Gu C, Sabatini BL. Midbrain dopamine neurons sustain inhibitory transmission using plasma membrane uptake of GABA, not synthesis. eLife 2014; 3:e01936. [PMID: 24843012 PMCID: PMC4001323 DOI: 10.7554/elife.01936] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Synaptic transmission between midbrain dopamine neurons and target neurons in the striatum is essential for the selection and reinforcement of movements. Recent evidence indicates that nigrostriatal dopamine neurons inhibit striatal projection neurons by releasing a neurotransmitter that activates GABAA receptors. Here, we demonstrate that this phenomenon extends to mesolimbic afferents, and confirm that the released neurotransmitter is GABA. However, the GABA synthetic enzymes GAD65 and GAD67 are not detected in midbrain dopamine neurons. Instead, these cells express the membrane GABA transporters mGAT1 (Slc6a1) and mGAT4 (Slc6a11) and inhibition of these transporters prevents GABA co-release. These findings therefore indicate that GABA co-release is a general feature of midbrain dopaminergic neurons that relies on GABA uptake from the extracellular milieu as opposed to de novo synthesis. This atypical mechanism may confer dopaminergic neurons the flexibility to differentially control GABAergic transmission in a target-dependent manner across their extensive axonal arbors. DOI:http://dx.doi.org/10.7554/eLife.01936.001 The electrical signals that are fired along neurons cannot be transmitted across the small gaps, called synapses that are found between neurons. Instead, the neuron sending the signal releases chemicals called neurotransmitters into the synapse. These neurotransmitters bind to receptor proteins on the surface of the second neuron and control how it fires. A neurotransmitter called dopamine plays a key role in the circuits of the brain that control how we learn certain tasks involving movement. In particular, two populations of neurons from the midbrain that release dopamine target the striatum, an area of the brain that is responsible for motor control. These neurons also release other neurotransmitters, but the identity of these other chemicals is not known, and the details of the interaction between the neurons and the striatum are poorly understood. Previous research showed that some of the midbrain neurons activate receptors that normally respond to a neurotransmitter called gamma-aminobutyric acid (GABA). However, several different chemicals can trigger this receptor. Using a range of techniques, Tritsch et al. now confirm that dopamine neurons release GABA alongside dopamine, and that this applies to both sets of the dopamine-producing neurons that feed into the striatum. Some neurons can manufacture GABA from amino acids found in their internal fluid. However, Tritsch et al. could not detect the enzymes needed for this reaction in dopamine-producing neurons. Instead, these neurons contain proteins that can transport GABA across the cell membrane, which suggests that the neurons collect GABA from the extracellular fluid that surrounds them. DOI:http://dx.doi.org/10.7554/eLife.01936.002
Collapse
Affiliation(s)
- Nicolas X Tritsch
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Won-Jong Oh
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Chenghua Gu
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Bernardo L Sabatini
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| |
Collapse
|
34
|
Sandhu KV, Lang D, Müller B, Nullmeier S, Yanagawa Y, Schwegler H, Stork O. Glutamic acid decarboxylase 67 haplodeficiency impairs social behavior in mice. GENES BRAIN AND BEHAVIOR 2014; 13:439-50. [DOI: 10.1111/gbb.12131] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 01/06/2014] [Accepted: 03/05/2014] [Indexed: 12/31/2022]
Affiliation(s)
- K. V. Sandhu
- Department of Genetics & Molecular Neurobiology; Institute of Biology; Magdeburg Germany
| | - D. Lang
- Department of Genetics & Molecular Neurobiology; Institute of Biology; Magdeburg Germany
| | - B. Müller
- Department of Genetics & Molecular Neurobiology; Institute of Biology; Magdeburg Germany
| | - S. Nullmeier
- Institute of Anatomy; Otto-von-Guericke University Magdeburg; Magdeburg Germany
| | - Y. Yanagawa
- Department of Genetic and Behavioral Neuroscience; Gunma University Graduate School of Medicine and JST, CREST; Maebashi Japan
| | - H. Schwegler
- Institute of Anatomy; Otto-von-Guericke University Magdeburg; Magdeburg Germany
- Center for Behavioral Brain Sciences; Magdeburg Germany
| | - O. Stork
- Department of Genetics & Molecular Neurobiology; Institute of Biology; Magdeburg Germany
- Center for Behavioral Brain Sciences; Magdeburg Germany
| |
Collapse
|
35
|
CGRP inhibits neurons of the bed nucleus of the stria terminalis: implications for the regulation of fear and anxiety. J Neurosci 2014; 34:60-5. [PMID: 24381268 DOI: 10.1523/jneurosci.3473-13.2014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The bed nucleus of the stria terminalis (BNST) is thought to generate anxiety-like states via its projections to autonomic and neuroendocrine regulatory structures of the brain. However, because most BNST cells are GABAergic, they are expected to inhibit target neurons. In contrast with this, infusion of calcitonin gene-related peptide (CGRP) into BNST was reported to potentiate anxiety while activating BNST targets. The present study aimed to shed light on this paradox. The CGRP innervation of BNST originates in the pontine parabrachial nucleus and targets its anterolateral sector (BNST-AL). Thus, we investigated the effects of CGRP on BNST-AL neurons using patch recordings in vitro in male rats. CGRP did not alter the passive properties of BNST-AL cells but increased the amplitude of IPSPs evoked by stimulation of the stria terminalis (ST). However, IPSP paired-pulse ratios were unchanged by CGRP, and there was no correlation between IPSP potentiation and variance, suggesting that CGRP acts postsynaptically. Consistent with this, CGRP hyperpolarized the GABA-A reversal of BNST-AL cells. These results indicate that CGRP increases ST-evoked GABA-A IPSPs and hyperpolarizes their reversal potential through a postsynaptic change in Cl(-) homeostasis. Overall, our findings suggest that CGRP potentiates anxiety-like behaviors and increases neural activity in BNST targets, by inhibiting BNST-AL cells, supporting the conclusion that BNST-AL exerts anxiolytic effects.
Collapse
|
36
|
Seo S, Leitch B. Altered thalamic GABAA-receptor subunit expression in the stargazer mouse model of absence epilepsy. Epilepsia 2014; 55:224-32. [PMID: 24417662 DOI: 10.1111/epi.12500] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/29/2013] [Indexed: 01/11/2023]
Abstract
PURPOSE Absence seizures, also known as petit mal seizures, arise from disruptions within the cortico-thalamocortical network. Interconnected circuits within the thalamus consisting of inhibitory neurons of the reticular thalamic nucleus (RTN) and excitatory relay neurons of the ventral posterior (VP) complex, generate normal intrathalamic oscillatory activity. The degree of synchrony in this network determines whether normal (spindle) or pathologic (spike wave) oscillations occur; however, the cellular and molecular mechanisms underlying absence seizures are complex and multifactorial and currently are not fully understood. Recent experimental evidence from rodent models suggests that regional alterations in γ-aminobutyric acid (GABA)ergic inhibition may underlie hypersynchronous oscillations featured in absence seizures. The aim of the current study was to investigate whether region-specific differences in GABAA receptor (GABAAR) subunit expression occur in the VP and RTN thalamic regions in the stargazer mouse model of absence epilepsy where the primary deficit is in α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) expression. METHODS Immunofluorescence confocal microscopy and semiquantitative Western blot analysis were used to investigate region-specific changes in GABAAR subunits in the thalamus of the stargazer mouse model of absence epilepsy to determine whether changes in GABAergic inhibition could contribute to the mechanisms underlying seizures in this model of absence epilepsy. KEY FINDINGS Immunofluorescence confocal microscopy revealed that GABAAR α1 and β2 subunits are predominantly expressed in the VP, whereas α3 and β3 subunits are localized primarily in the RTN. Semiquantitative Western blot analysis of VP and RTN samples from epileptic stargazers and their nonepileptic littermates showed that GABAAR α1 and β2 subunit expression levels in the VP were significantly increased (α1: 33%, β2: 96%) in epileptic stargazers, whereas α3 and β3 subunits in the RTN were unchanged in the epileptic mice compared to nonepileptic control littermates. SIGNIFICANCE These findings suggest that region-specific differences in GABAAR subunits in the thalamus of epileptic mice, specifically up-regulation of GABAARs in the thalamic relay neurons of the VP, may contribute to generation of hypersynchronous thalamocortical activity in absence seizures. Understanding region-specific differences in GABAAR subunit expression could help elucidate some of the cellular and molecular mechanisms underlying absence seizures and thereby identify targets by which drugs can modulate the frequency and severity of epileptic seizures. Ultimately, this information could be crucial for the development of more specific and effective therapeutic drugs for treatment of this form of epilepsy.
Collapse
Affiliation(s)
- Steve Seo
- Department of Anatomy, Brain Health Research Centre, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | | |
Collapse
|
37
|
Czéh B, Abrahám H, Tahtakran S, Houser CR, Seress L. Number and regional distribution of GAD65 mRNA-expressing interneurons in the rat hippocampal formation. ACTA BIOLOGICA HUNGARICA 2013; 64:395-413. [PMID: 24275587 DOI: 10.1556/abiol.64.2013.4.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In rodent models for neuropsychiatric disorders reduced number of hippocampal interneurons have been reported, but the total number of GABAergic neurons in the normal rat hippocampus is yet unknown. We used in situ hybridization method to label the 65 isoform of glutamic acid decarboxylase (GAD65) and counted the number of GAD65 mRNA-expressing neurons along the entire septo-temporal axis of the hippocampus. We found that 2/3 of the interneurons were in Ammon's horn (61,590) and 1/3 in the dentate gyrus (28,000). We observed the following numbers in Ammon's horn: CA3 area 33,400, CA2 area 4,190, CA1 area 24,000 and in the dentate gyrus: 6,000 in the molecular and 9,000 in the granule cell layers and 13,000 in the hilus. GAD65 mRNA-expressing neurons were significantly more numerous in dorsal than in ventral hippocampus. The ratio between interneurons and principal cells was lowest in the granule cell layer (0.9%) and highest in hilus (21%). In Ammon's horn this ratio was constant being 13% in CA3 and 8% in CA1-2 areas. In the entire hippocampal formation, the interneuron/principal cell ratio was 6%, with a significant difference between Ammon's horn (9.5%) and the dentate gyrus (2.8%) including the hilus. Such low ratios could suggest that even a limited loss of GABAergic neurons in the hippocampus may have a considerable functional impact.
Collapse
Affiliation(s)
- B Czéh
- University of Pécs Department of Laboratory Medicine, Faculty of Medicine H-7624 Pécs Hungary Aarhus University Hospital Centre for Psychiatric Research 8240 Risskov Denmark University of Pécs Szentágothai János Research Center, Neuroendocrinology Research Group H-7624 Pécs Hungary
| | | | | | | | | |
Collapse
|
38
|
Dimitrov EL, Yanagawa Y, Usdin TB. Forebrain GABAergic projections to locus coeruleus in mouse. J Comp Neurol 2013; 521:2373-97. [PMID: 23296594 DOI: 10.1002/cne.23291] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 10/30/2012] [Accepted: 12/27/2012] [Indexed: 01/10/2023]
Abstract
The noradrenergic locus coeruleus (LC) regulates arousal, memory, sympathetic nervous system activity, and pain. Forebrain projections to LC have been characterized in rat, cat, and primates, but not systematically in mouse. We surveyed mouse forebrain LC-projecting neurons by examining retrogradely labeled cells following LC iontophoresis of Fluoro-Gold and anterograde LC labeling after forebrain injection of biotinylated dextran amine or viral tracer. Similar to other species, the central amygdalar nucleus (CAmy), anterior hypothalamus, paraventricular nucleus, and posterior lateral hypothalamic area (PLH) provide major LC inputs. By using mice expressing green fluorescent protein in γ-aminobutyric acid (GABA)ergic neurons, we found that more than one-third of LC-projecting CAmy and PLH neurons are GABAergic. LC colocalization of biotinylated dextran amine, following CAmy or PLH injection, with either green fluorescent protein or glutamic acid decarboxylase (GAD)65/67 immunoreactivity confirmed these GABAergic projections. CAmy injection of adeno-associated virus encoding channelrhodopsin-2-Venus showed similar fiber labeling and association with GAD65/67-immunoreactive (ir) and tyrosine hydroxylase (TH)-ir neurons. CAmy and PLH projections were densest in a pericoerulear zone, but many fibers entered the LC proper. Close apposition between CAmy GABAergic projections and TH-ir processes suggests that CAmy GABAergic neurons may directly inhibit noradrenergic principal neurons. Direct LC neuron targeting was confirmed by anterograde transneuronal labeling of LC TH-ir neurons following CAmy or PLH injection of a herpes virus that expresses red fluorescent protein following activation by Cre recombinase in mice that express Cre recombinase in GABAergic neurons. This description of GABAergic projections from the CAmy and PLH to the LC clarifies important forebrain sources of inhibitory control of central nervous system noradrenergic activity.
Collapse
Affiliation(s)
- Eugene L Dimitrov
- Section on Fundamental Neuroscience, National Institute of Mental Health, Bethesda, Maryland 20892, USA
| | | | | |
Collapse
|
39
|
Haufler D, Nagy FZ, Pare D. Neuronal correlates of fear conditioning in the bed nucleus of the stria terminalis. Learn Mem 2013; 20:633-41. [PMID: 24131794 PMCID: PMC3799415 DOI: 10.1101/lm.031799.113] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Lesion and inactivation studies indicate that the central amygdala (CeA) participates in the expression of cued and contextual fear, whereas the bed nucleus of the stria terminalis (BNST) is only involved in the latter. The basis for this functional dissociation is unclear because CeA and BNST form similar connections with the amygdala and brainstem fear effectors. To address this question, we recorded neurons in the anterolateral (AL) and anteromedial (AM) regions of BNST in rats subjected to auditory fear conditioning. During habituation, few neurons were responsive to the conditioned stimulus (CS). After fear conditioning, 20% of BNST-AL neurons developed inhibitory responses to the CS. In BNST-AM, 26% of neurons developed positive CS responses. The behavior of BNST-AM and -AL neurons during contextual fear paralleled their CS responsiveness: More BNST-AM neurons fired at higher rates during contextual freezing than movement, whereas the opposite was seen in BNST-AL cells. These findings point to regional differences in the activity of BNST-AL and -AM in relation to learned fear, raising the possibility that they exert opposite influences on fear output networks. However, given the similar behavior of BNST-AM and -AL neurons in relation to cued and contextual fear, it remains unclear why lesion and inactivation of BNST differentially affect these two types of fear. Either neurons in a different BNST sector, not explored here, show a different activity profile in relation to the two forms of fear or inactivation/lesion studies inadvertently affected a structure adjacent to BNST, which is involved in contextual fear.
Collapse
Affiliation(s)
- Darrell Haufler
- Center for Molecular & Behavioral Neuroscience, Rutgers State University, Newark, New Jersey 07102, USA
| | | | | |
Collapse
|
40
|
Wittmann G, Hrabovszky E, Lechan RM. Distinct glutamatergic and GABAergic subsets of hypothalamic pro-opiomelanocortin neurons revealed by in situ hybridization in male rats and mice. J Comp Neurol 2013; 521:3287-302. [PMID: 23640796 PMCID: PMC4003895 DOI: 10.1002/cne.23350] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 04/07/2013] [Accepted: 04/25/2013] [Indexed: 11/10/2022]
Abstract
Pro-opiomelanocortin (POMC) and agouti-related protein (AGRP) neurons in the hypothalamus regulate various aspects of energy homeostasis and metabolism. POMC and AGRP neurons, respectively, agonize and antagonize melanocortin receptors on their common downstream neurons. However, it is unknown whether they also reciprocally stimulate and inhibit the same neurons by amino acid transmitters. Whereas AGRP neurons are mostly GABAergic, surprisingly, only a small population of POMC neurons has been found to be glutamatergic, and a significantly larger subpopulation to be GABAergic. To further examine amino acid phenotypes of POMC neurons, we studied mRNA expression for the glutamatergic marker, type 2 vesicular glutamate transporter (VGLUT2), and the GABA synthetic enzyme, glutamic acid decarboxylase 67 (GAD67), in POMC neurons of both rats and mice by using in situ hybridization techniques. In rats, approximately 58% of POMC neurons were labeled for VGLUT2 and 37% for GAD67 mRNA. In mice, approximately 43% of POMC neurons contained VGLUT2, and 54% contained GAD67 mRNA. In both species, a prominent mediolateral distribution pattern was observed at rostral and mid levels of the POMC cell group with VGLUT2-POMC neurons dominating in lateral portions and GAD67-POMC neurons in medial portions. These data demonstrate that both glutamatergic and GABAergic cells are present in comparably significant numbers among POMC neurons. Their glutamatergic or GABAergic phenotype may represent a major functional division within the POMC cell group.
Collapse
Affiliation(s)
- Gábor Wittmann
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
| | - Erik Hrabovszky
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary
| | - Ronald M. Lechan
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| |
Collapse
|
41
|
Zhao C, Eisinger B, Gammie SC. Characterization of GABAergic neurons in the mouse lateral septum: a double fluorescence in situ hybridization and immunohistochemical study using tyramide signal amplification. PLoS One 2013; 8:e73750. [PMID: 23967349 PMCID: PMC3742568 DOI: 10.1371/journal.pone.0073750] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 07/26/2013] [Indexed: 01/02/2023] Open
Abstract
Gamma-aminobutyric acid (GABA) neurotransmission in the lateral septum (LS) is implicated in modulating various behavioral processes, including emotional reactivity and maternal behavior. However, identifying the phenotype of GABAergic neurons in the CNS has been hampered by the longstanding inability to reliably detect somal immunoreactivity for GABA or glutamic acid decarboxylase (GAD), the enzyme that produces GABA. In this study, we designed unique probes for both GAD65 (GAD2) and GAD67 (GAD1), and used fluorescence in Situ hybridization (FISH) with tyramide signal amplification (TSA) to achieve unequivocal detection of cell bodies of GABAergic neurons by GAD mRNAs. We quantitatively characterized the expression and chemical phenotype of GABAergic neurons across each subdivision of LS and in cingulate cortex (Cg) and medial preoptic area (MPOA) in female mice. Across LS, almost all GAD65 mRNA-expressing neurons were found to contain GAD67 mRNA (approximately 95-98%), while a small proportion of GAD67 mRNA-containing neurons did not express GAD65 mRNA (5-14%). Using the neuronal marker NeuN, almost every neuron in LS (> 90%) was also found to be GABA-positive. Interneuron markers using calcium-binding proteins showed that LS GABAergic neurons displayed immunoreactivity for calbindin (CB) or calretinin (CR), but not parvalbumin (PV); almost all CB- or CR-immunoreactive neurons (98-100%) were GABAergic. The proportion of GABAergic neurons immunoreactive for CB or CR varied depending on the subdivisions examined, with the highest percentage of colocalization in the caudal intermediate LS (LSI) (approximately 58% for CB and 35% for CR). These findings suggest that the vast majority of GABAergic neurons within the LS have the potential for synthesizing GABA via the dual enzyme systems GAD65 and GAD67, and each subtype of GABAergic neurons identified by distinct calcium-binding proteins may exert unique roles in the physiological function and neuronal circuitry of the LS.
Collapse
Affiliation(s)
- Changjiu Zhao
- Department of Zoology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
| | | | | |
Collapse
|
42
|
Rodríguez-Sierra OE, Turesson HK, Pare D. Contrasting distribution of physiological cell types in different regions of the bed nucleus of the stria terminalis. J Neurophysiol 2013; 110:2037-49. [PMID: 23926040 DOI: 10.1152/jn.00408.2013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
We characterized the electroresponsive and morphological properties of neurons in the bed nucleus of the stria terminalis (BNST). Previously, Rainnie and colleagues distinguished three cell types in the anterolateral region of BNST (BNST-AL): low-threshold bursting cells (LTB; type II) and regular spiking neurons that display time-dependent (RS; type I) or fast (fIR; type III) inward rectification in the hyperpolarizing direction (Hammack SE, Mania I, Rainnie DG. J Neurophysiol 98: 638-56, 2007). We report that the same neuronal types exist in the anteromedial (AM) and anteroventral (AV) regions of BNST. In addition, we observed two hitherto unreported cell types: late-firing (LF) cells, only seen in BNST-AL, that display a conspicuous delay to firing, and spontaneously active (SA) neurons, only present in BNST-AV, firing continuously at rest. However, the feature that most clearly distinguished the three BNST regions was the incidence of LTB cells (approximately 40-70%) and the strength of their bursting behavior (both higher in BNST-AM and AV relative to AL). The incidence of RS cells was similar in the three regions (∼25%), whereas that of fIR cells was higher in BNST-AL (∼25%) than AV or AM (≤8%). With the use of biocytin, two dominant morphological cell classes were identified but they were not consistently related to particular physiological phenotypes. One neuronal class had highly branched and spiny dendrites; the second had longer but poorly branched and sparsely spiny dendrites. Both often exhibited dendritic varicosities. Since LTB cells prevail in BNST, it will be important to determine what inputs set their firing mode (tonic vs. bursting) and in what behavioral states.
Collapse
Affiliation(s)
- Olga E Rodríguez-Sierra
- Center for Molecular and Behavioral Neuroscience, Rutgers State University, Newark, New Jersey; and
| | | | | |
Collapse
|
43
|
Jarvie BC, Hentges ST. Expression of GABAergic and glutamatergic phenotypic markers in hypothalamic proopiomelanocortin neurons. J Comp Neurol 2013; 520:3863-76. [PMID: 22522889 DOI: 10.1002/cne.23127] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Hypothalamic proopiomelanocortin (POMC) neurons have traditionally been defined by their peptide transmitters, which are important regulators of energy balance and reward. Recent work shows that POMC neurons can also release the amino acid transmitters γ-aminobutyric acid (GABA) and glutamate, although studying GABAergic and glutamatergic populations of POMC neurons has been hindered by the difficulty in reliably identifying amino acid (AA) transmitter phenotypes. In the present study, fluorescent in situ hybridization and immunohistochemistry were used to identify POMC neurons and to detect the presence of mRNA for the transporters responsible for packaging either GABA (vesicular GABA transporter [vGAT]) or glutamate (vesicular glutamate transporter [vGLUT]) into vesicles, as well as the enzymes responsible for GABA synthesis, glutamic acid decarboxylase (GAD)65 and GAD67. Approximately 7% of POMC neurons expressed vGlut2 and the highest percentage of vGlut2-positive POMC cells were located in the rostral arcuate nucleus. Despite the reports of GABA release from POMC neurons, vGat was not detected in POMC neurons, although Gad65 and Gad67 were present in ~40% of POMC neurons. Approximately half of the vGlut2-expressing POMC cells also expressed Gad65. Markers of neurotransmitter phenotype were better detected by using in situ hybridization techniques rather than transgenic expression of fluorophores under the control of the vGat or Gad67 promoters. It is now clear that the expression of markers of AA phenotype provides a useful means to identify distinct subpopulations of POMC neurons. Additionally, the method described will be useful to explore the possibility that plasticity of AA phenotype is an important aspect of POMC neuron function.
Collapse
Affiliation(s)
- Brooke C Jarvie
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523, USA
| | | |
Collapse
|
44
|
Bowman BR, Kumar NN, Hassan SF, McMullan S, Goodchild AK. Brain sources of inhibitory input to the rat rostral ventrolateral medulla. J Comp Neurol 2013; 521:213-32. [PMID: 22740031 DOI: 10.1002/cne.23175] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 05/02/2012] [Accepted: 06/20/2012] [Indexed: 12/19/2022]
Abstract
The rostral ventrolateral medulla (RVLM) contains neurons critical for cardiovascular, respiratory, metabolic, and motor control. The activity of these neurons is controlled by inputs from multiple identified brain regions; however, the neurochemistry of these inputs is largely unknown. Gamma-aminobutyric acid (GABA) and enkephalin tonically inhibit neurons within the RVLM. The aim of this study was to identify all brain regions that provide GABAergic or enkephalinergic input to the rat RVLM. Neurons immunoreactive for cholera toxin B (CTB-ir), retrogradely transported from the RVLM, were assessed for expression of glutamic acid decarboxylase (GAD67) or preproenkephalin (PPE) mRNA using in situ hybridization. GAD67 mRNA was expressed in CTB-ir neurons in the following regions: the nucleus of the solitary tract (NTS, 6% of CTB-ir neurons), area postrema (AP, 8%), caudal ventrolateral medulla (17%), midline raphe (40%), ventrolateral periaqueductal gray (VLPAG, 15%), lateral hypothalamic area (LHA, 25%), central nucleus of the amygdala (CeA, 77%), sublenticular extended amygdala (SLEA, 86%), interstitial nucleus of the posterior limb of the anterior commissure (IPAC, 56%), bed nucleus of the stria terminals (BNST, 59%), and medial preoptic area (MPA, 53%). PPE mRNA was expressed in CTB-ir neurons in the following regions: the NTS (14% of CTB-ir neurons), midline raphe (26%), LHA (22%), zona incerta (ZI, 15%), CeA (5%), paraventricular nucleus (PVN, 13%), SLEA (66%), and MPA (26%). Thus, limited brain regions contribute GABAergic and/or enkephalinergic input to the RVLM. Multiple neurochemically distinct pathways originate from these brain regions projecting to the RVLM.
Collapse
Affiliation(s)
- Belinda R Bowman
- Australian School of Advanced Medicine, Macquarie University, 2109, NSW Australia
| | | | | | | | | |
Collapse
|
45
|
Turesson HK, Rodríguez-Sierra OE, Pare D. Intrinsic connections in the anterior part of the bed nucleus of the stria terminalis. J Neurophysiol 2013; 109:2438-50. [PMID: 23446692 DOI: 10.1152/jn.00004.2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Intrinsic connections in the anterior portion of the bed nucleus of the stria terminalis (BNST-A) were studied using patch recordings and ultraviolet (UV) glutamate uncaging (GU) in vitro. UV light was delivered at small BNST-A sites in a grid-like pattern while evoked responses were monitored in different BNST-A regions. Three sectors were distinguished in the BNST-A using fiber bundles readily identifiable in transilluminated slices: the anterior commissure, dividing the BNST-A into dorsal and ventral (BNST-AV) regions, and the intra-BNST component of the stria terminalis, subdividing the dorsal portion into medial (BNST-AM) and lateral (BNST-AL) regions. Overall, GU elicited GABAergic inhibitory postsynaptic potentials (IPSPs) more frequently than excitatory postsynaptic potentials. The incidence of intraregional connections was higher than interregional links. With respect to the latter, asymmetric connections were seen between different parts of the BNST-A. Indeed, while reciprocal connections were found between the BNST-AL and BNST-AM, BNST-AL to BNST-AM connections were more frequent than in the opposite direction. Similarly, while GU in the BNST-AM or BNST-AL often elicited IPSPs in BNST-AV cells, the opposite was rarely seen. Within the BNST-AM, connections were polarized, with dorsal GU sites eliciting IPSPs in more ventrally located cells more frequently than the opposite. This trend was not seen in other regions of the BNST. Consistent with this, most BNST-AM cells had dorsally directed dendrites and ventrally ramified axons, whereas this morphological polarization was not seen in other parts of the BNST-A. Overall, our results reveal a hitherto unsuspected level of asymmetry in the connections within and between different BNST-A regions, implying a degree of interdependence in their activity.
Collapse
Affiliation(s)
- Hjalmar K Turesson
- Center for Molecular and Behavioral Neuroscience, Rutgers State University, Newark, New Jersey 07102, USA
| | | | | |
Collapse
|
46
|
Tjen-A-Looi SC, Guo ZL, Li M, Longhurst JC. Medullary GABAergic mechanisms contribute to electroacupuncture modulation of cardiovascular depressor responses during gastric distention in rats. Am J Physiol Regul Integr Comp Physiol 2013; 304:R321-32. [PMID: 23302958 DOI: 10.1152/ajpregu.00451.2012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Electroacupuncture (EA) at P5-P6 acupoints overlying the median nerves typically reduces sympathoexcitatory blood pressure (BP) reflex responses in eucapnic rats. Gastric distention in hypercapnic acidotic rats, by activating both vagal and sympathetic afferents, decreases heart rate (HR) and BP through actions in the rostral ventrolateral medulla (rVLM) and nucleus ambiguus (NAmb), leading to sympathetic withdrawal and parasympathetic activation, respectively. A GABAA mechanism in the rVLM mediates the decreased sympathetic outflow. The present study investigated the hypothesis that EA modulates gastric distention-induced hemodynamic depressor and bradycardia responses through nuclei that process parasympathetic and sympathetic outflow. Anesthetized hypercapnic acidotic rats manifested repeatable decreases in BP and HR with gastric distention every 10 min. Bilateral EA at P5-P6 for 30 min reversed the hypotensive response from -26 ± 3 to -6 ± 1 mmHg and the bradycardia from -35 ± 11 to -10 ± 3 beats/min for a period that lasted more than 70 min. Immunohistochemistry and in situ hybridization to detect c-Fos protein and GAD 67 mRNA expression showed that GABAergic caudal ventral lateral medulla (cVLM) neurons were activated by EA. Glutamatergic antagonism of cVLM neurons with kynurenic acid reversed the actions of EA. Gabazine used to block GABAA receptors microinjected into the rVLM or cVLM reversed EA's action on both the reflex depressor and bradycardia responses. EA modulation of the decreased HR was inhibited by microinjection of gabazine into the NAmb. Thus, EA through GABAA receptor mechanisms in the rVLM, cVLM, and NAmb modulates gastric distention-induced reflex sympathoinhibition and vagal excitation.
Collapse
Affiliation(s)
- Stephanie C Tjen-A-Looi
- Susan Samueli Center for Integrative Medicine, Department of Medicine, School of Medicine, University of California, Irvine, CA 92697, USA.
| | | | | | | |
Collapse
|
47
|
Heldt SA, Mou L, Ressler KJ. In vivo knockdown of GAD67 in the amygdala disrupts fear extinction and the anxiolytic-like effect of diazepam in mice. Transl Psychiatry 2012; 2:e181. [PMID: 23149445 PMCID: PMC3565763 DOI: 10.1038/tp.2012.101] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In mammals, γ-aminobutyric acid (GABA) transmission in the amygdala is particularly important for controlling levels of fear and anxiety. Most GABA synthesis in the brain is catalyzed in inhibitory neurons from L-glutamic acid by the enzyme glutamic acid decarboxylase 67 (GAD67). In the current study, we sought to examine the acquisition and extinction of conditioned fear in mice with knocked down expression of the GABA synthesizing enzyme GAD67 in the amygdala using a lentiviral-based (LV) RNA interference strategy to locally induce loss-of-function. In vitro experiments revealed that our LV-siRNA-GAD67 construct diminished the expression of GAD67 as determined with western blot and fluorescent immunocytochemical analyses. In vivo experiments, in which male C57BL/6J mice received bilateral amygdala microinjections, revealed that LV-siRNA-GAD67 injections produce significant inhibition of endogenous GAD67 when compared with control injections. In contrast, no significant changes in GAD65 expression were detected in the amygdala, validating the specificity of LV knockdown. Behavioral experiments showed that LV knockdown of GAD67 results in a deficit in the extinction, but not the acquisition or retention, of fear as measured by conditioned freezing. GAD67 knockdown did not affect baseline locomotion or basal measures of anxiety as measured in open field apparatus. However, diminished GAD67 in the amygdala blunted the anxiolytic-like effect of diazepam (1.5 mg kg(-1)) as measured in the elevated plus maze. Together, these studies suggest that of GABAergic transmission in amygdala mediates the inhibition of conditioned fear and the anxiolytic-like effect of diazepam in adult mice.
Collapse
Affiliation(s)
- S A Heldt
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA.
| | - L Mou
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
| | - K J Ressler
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA,Howard Hughes Medical Institute, Bethesda, MD, USA
| |
Collapse
|
48
|
The fraction of cortical GABAergic neurons is constant from near the start of cortical neurogenesis to adulthood. J Neurosci 2012; 32:4755-61. [PMID: 22492031 DOI: 10.1523/jneurosci.6412-11.2012] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Approximately one in five neurons is GABAergic in many neocortical areas and species, forming a critical balance between inhibition and excitation in adult circuits. During development, cortical GABAergic neurons are generated in ventral telencephalon and migrate up to developing cortex where the excitatory glutamatergic neurons are born. We ask here: when during development is the adult GABAergic/glutamatergic neuron ratio first established? To answer this question, we have determined the fraction of all neocortical GABAergic neurons that will become inhibitory (GAD67(+)) in mice from embryonic day 10.5 (E10.5) to postnatal day 28 (P28). We find that this fraction is close to 1/5, the adult value, starting from early in corticogenesis (E14.5, when GAD67(+) neurons are still migrating tangentially to the cortex) and continuing at the same 1/5 value throughout the remainder of brain development. Thus our data indicate the one-in-five fraction of GABAergic neurons is already established during their neuronal migration and well before significant synapse formation.
Collapse
|
49
|
Bota M, Sporns O, Swanson LW. Neuroinformatics analysis of molecular expression patterns and neuron populations in gray matter regions: the rat BST as a rich exemplar. Brain Res 2012; 1450:174-93. [PMID: 22421015 DOI: 10.1016/j.brainres.2012.02.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 02/12/2012] [Accepted: 02/14/2012] [Indexed: 10/28/2022]
Abstract
The rat bed nuclei of the stria terminalis (BST) is an important part of the cerebral nuclei, both structurally and functionally. However, the literature is rather scarce and more importantly, often contradictory. In this paper we review the literature related to neuron populations reported in different rat BST parts, and to a set of more than 50 expressed molecules. The information related to neuron populations and molecules detected in the BST was expertly collated manually in a publicly available neuroinformatics system, the Brain Architecture Knowledge Management System (BAMS; http://brancusi.usc.edu/bkms). Using the tools implemented in BAMS, we organized the collated information, and further analyzed it statistically. The result of our analysis over the set of >50 expressed molecules confirms the BST parcellation scheme proposed by Swanson in 2004, with two exceptions. We present and discuss these results, and propose refined parcellation ventrally in the BST. We also review and discuss the presence of cholinergic neurons in the BST, and of neuron populations that express serotonin receptors. This review is one of the most comprehensive for the rat BST published in the literature, and it was possible only by using neuroinformatics tools.
Collapse
Affiliation(s)
- Mihail Bota
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | | | | |
Collapse
|
50
|
Trifonov S, Houtani T, Kase M, Toida K, Maruyama M, Yamashita Y, Shimizu JI, Sugimoto T. Lateral regions of the rodent striatum reveal elevated glutamate decarboxylase 1 mRNA expression in medium-sized projection neurons. Eur J Neurosci 2012; 35:711-22. [PMID: 22332935 DOI: 10.1111/j.1460-9568.2012.08001.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The GABA-synthesizing enzymes glutamate decarboxylase (GAD)1 and GAD2 are universally contained in GABAergic neurons in the central nervous system of the mouse and rat. The two isoforms are almost identically expressed throughout the brain and spinal cord. By using in situ hybridization, we found that the mouse lateral striatum concentrates medium-sized projection neurons with high-level expression of GAD1, but not of GAD2, mRNA. This was confirmed with several types of riboprobe, including those directed to the 5'-noncoding, 3'-noncoding and coding regions. Immunohistochemical localization of GAD1 also revealed predominant localization of the enzyme in the same striatal region. The lateral region of the mouse striatum, harboring such neurons, is ovoid in shape and extends between interaural +4.8 and +2.8, and at lateral 2.8 and dorsoventral 2.0. This intriguing region corresponds to the area that receives afferent inputs from the primary motor and sensory cortex that are presumably related to mouth and forelimb representations. The lateral striatum is included in the basal ganglia-thalamocortical loop, and is most vulnerable to various noxious stimuli in the neurodegeneration processes involving the basal ganglia. We have confirmed elevated expression of GAD1 mRNA, but not of GAD2 mRNA, also in the rat lateral striatum. Image analysis favored the view that the regional increase is caused by elevated cellular expression, and that the greatest number of medium-sized spiny neurons were positive for GAD1 mRNA. The GAD1 mRNA distribution in the mouse lateral striatum partially resembled those of GPR155 and cannabinoid receptor type 1 mRNAs, suggesting functional cooperation in some neurons.
Collapse
Affiliation(s)
- Stefan Trifonov
- Department of Anatomy and Brain Science, Kansai Medical University, Moriguchi, Osaka 570-8506, Japan
| | | | | | | | | | | | | | | |
Collapse
|