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Nordenankar, Karin
Publications (10 of 14) Show all publications
Fredriksson, R., Sreedharan, S., Nordenankar, K., Alsiö, J., Lindberg, F. A., Hutchinson, A., . . . Schiöth, H. B. (2019). The polyamine transporter Slc18b1(VPAT) is important for both short and long time memory and for regulation of polyamine content in the brain.. PLoS Genetics, 15(12), Article ID e1008455.
Open this publication in new window or tab >>The polyamine transporter Slc18b1(VPAT) is important for both short and long time memory and for regulation of polyamine content in the brain.
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2019 (English)In: PLoS Genetics, ISSN 1553-7390, E-ISSN 1553-7404, Vol. 15, no 12, article id e1008455Article in journal (Refereed) Published
Abstract [en]

SLC18B1 is a sister gene to the vesicular monoamine and acetylcholine transporters, and the only known polyamine transporter, with unknown physiological role. We reveal that Slc18b1 knock out mice has significantly reduced polyamine content in the brain providing the first evidence that Slc18b1 is functionally required for regulating polyamine levels. We found that this mouse has impaired short and long term memory in novel object recognition, radial arm maze and self-administration paradigms. We also show that Slc18b1 KO mice have altered expression of genes involved in Long Term Potentiation, plasticity, calcium signalling and synaptic functions and that expression of components of GABA and glutamate signalling are changed. We further observe a partial resistance to diazepam, manifested as significantly lowered reduction in locomotion after diazepam treatment. We suggest that removal of Slc18b1 leads to reduction of polyamine contents in neurons, resulting in reduced GABA signalling due to long-term reduction in glutamatergic signalling.

National Category
Neurosciences
Identifiers
urn:nbn:se:uu:diva-401876 (URN)10.1371/journal.pgen.1008455 (DOI)000512336600007 ()31800589 (PubMedID)
Available from: 2020-01-09 Created: 2020-01-09 Last updated: 2020-03-25Bibliographically approved
Vrettou, M., Nordenankar, K., Segerström, L., Wallén-Mackenzie, Å., Fredriksson, R., Comasco, E. & Nylander, I. (2017). Vgluts In The Mesocorticolimbic Brain Of Adolescent Outbred Rats Exposed To Alcohol And Nicotine. Alcohol and Alcoholism, 52
Open this publication in new window or tab >>Vgluts In The Mesocorticolimbic Brain Of Adolescent Outbred Rats Exposed To Alcohol And Nicotine
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2017 (English)In: Alcohol and Alcoholism, ISSN 0735-0414, E-ISSN 1464-3502, Vol. 52Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
OXFORD UNIV PRESS, 2017
National Category
Substance Abuse
Identifiers
urn:nbn:se:uu:diva-345577 (URN)000417304100159 ()
Available from: 2018-03-09 Created: 2018-03-09 Last updated: 2018-03-09Bibliographically approved
Schweizer, N., Viereckel, T., Smith-Anttila, C. J. A., Nordenankar, K., Arvidsson, E., Mahmoudi, S., . . . Wallén-Mackenzie, Å. (2016). Reduced Vglut2/Slc17a6 Gene Expression Levels throughout the Mouse Subthalamic Nucleus Cause Cell Loss and Structural Disorganization Followed by Increased Motor Activity and Decreased Sugar Consumption. ENEURO, 3(5), Article ID UNSP e0264.
Open this publication in new window or tab >>Reduced Vglut2/Slc17a6 Gene Expression Levels throughout the Mouse Subthalamic Nucleus Cause Cell Loss and Structural Disorganization Followed by Increased Motor Activity and Decreased Sugar Consumption
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2016 (English)In: ENEURO, ISSN 2373-2822, Vol. 3, no 5, article id UNSP e0264Article in journal (Refereed) Published
Abstract [en]

The subthalamic nucleus (STN) plays a central role in motor, cognitive, and affective behavior. Deep brain stimulation (DBS) of the STN is the most common surgical intervention for advanced Parkinson's disease (PD), and STN has lately gained attention as target for DBS in neuropsychiatric disorders, including obsessive compulsive disorder, eating disorders, and addiction. Animal studies using STN-DBS, lesioning, or inactivation of STN neurons have been used extensively alongside clinical studies to unravel the structural organization, circuitry, and function of the STN. Recent studies in rodent STN models have exposed different roles for STN neurons in reward-related functions. We have previously shown that the majority of STN neurons express the vesicular glutamate transporter 2 gene (Vglut2/Slc17a6) and that reduction of Vglut2 mRNA levels within the STN of mice [conditional knockout (cKO)] causes reduced postsynaptic activity and behavioral hyperlocomotion. The cKO mice showed less interest in fatty rewards, which motivated analysis of reward-response. The current results demonstrate decreased sugar consumption and strong rearing behavior, whereas biochemical analyses show altered dopaminergic and peptidergic activity in the striatum. The behavioral alterations were in fact correlated with opposite effects in the dorsal versus the ventral striatum. Significant cell loss and disorganization of the STN structure was identified, which likely accounts for the observed alterations. Rare genetic variants of the human VGLUT2 gene exist, and this study shows that reduced Vglut2/Slc17a6 gene expression levels exclusively within the STN of mice is sufficient to cause strong modifications in both the STN and the mesostriatal dopamine system.

Keywords
dopamine, dynorphin, glutamate, rearing, reward, self-administration
National Category
Neurology
Identifiers
urn:nbn:se:uu:diva-315932 (URN)10.1523/ENEURO.0264-16.2016 (DOI)000391930400042 ()
Funder
Swedish Research Council, Vetenskapsradet 2013-4657 2014-3804 2011-4423 2015-4870 2012-2304The Swedish Brain FoundationÅke Wiberg Foundation
Available from: 2017-02-22 Created: 2017-02-22 Last updated: 2017-09-05Bibliographically approved
Nordenankar, K., Smith-Anttila, C. J., Schweizer, N., Viereckel, T., Birgner, C., Mejia-Toiber, J., . . . Wallén-Mackenzie, Å. (2015). Increased hippocampal excitability and impaired spatial memory function in mice lacking VGLUT2 selectively in neurons defined by tyrosine hydroxylase promoter activity. Brain Structure and Function, 220(4), 2171-2190
Open this publication in new window or tab >>Increased hippocampal excitability and impaired spatial memory function in mice lacking VGLUT2 selectively in neurons defined by tyrosine hydroxylase promoter activity
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2015 (English)In: Brain Structure and Function, ISSN 1863-2653, E-ISSN 1863-2661, Vol. 220, no 4, p. 2171-2190Article in journal (Refereed) Published
Abstract [en]

Three populations of neurons expressing the vesicular glutamate transporter 2 (Vglut2) were recently described in the A10 area of the mouse midbrain, of which two populations were shown to express the gene encoding, the rate-limiting enzyme for catecholamine synthesis, tyrosine hydroxylase (TH).One of these populations ("TH-Vglut2 Class1") also expressed the dopamine transporter (DAT) gene while one did not ("TH-Vglut2 Class2"), and the remaining population did not express TH at all ("Vglut2-only"). TH is known to be expressed by a promoter which shows two phases of activation, a transient one early during embryonal development, and a later one which gives rise to stable endogenous expression of the TH gene. The transient phase is, however, not specific to catecholaminergic neurons, a feature taken to advantage here as it enabled Vglut2 gene targeting within all three A10 populations expressing this gene, thus creating a new conditional knockout. These knockout mice showed impairment in spatial memory function. Electrophysiological analyses revealed a profound alteration of oscillatory activity in the CA3 region of the hippocampus. In addition to identifying a novel role for Vglut2 in hippocampus function, this study points to the need for improved genetic tools for targeting of the diversity of subpopulations of the A10 area.

National Category
Neurology
Identifiers
urn:nbn:se:uu:diva-239640 (URN)10.1007/s00429-014-0778-9 (DOI)000356874700020 ()24802380 (PubMedID)
Funder
Swedish Research Council, 2007-5742, 2011-4747
Available from: 2014-12-29 Created: 2014-12-29 Last updated: 2017-12-05Bibliographically approved
Nordenankar, K., Bergfors, A. & Wallén-Mackenzie, Å. (2015). Targeted deletion of Vglut2 expression in the embryonal telencephalon promotes an anxiolytic phenotype of the adult mouse. Upsala Journal of Medical Sciences, 120(3)
Open this publication in new window or tab >>Targeted deletion of Vglut2 expression in the embryonal telencephalon promotes an anxiolytic phenotype of the adult mouse
2015 (English)In: Upsala Journal of Medical Sciences, ISSN 0300-9734, E-ISSN 2000-1967, Vol. 120, no 3Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Anxiety is a natural emotion experienced by all individuals. However, when anxiety becomes excessive, it contributes to the substantial group of anxiety disorders that affect one in three people and thus are among the most common psychiatric disorders. Anxiolysis, the reduction of anxiety, is mediated via several large groups of therapeutical compounds, but the relief is often only temporary, and increased knowledge of the neurobiology underlying anxiety is needed in order to improve future therapies.

AIM: We previously demonstrated that mice lacking forebrain expression of the Vesicular glutamate transporter 2 (Vglut2) from adolescence showed a strong anxiolytic behaviour as adults. In the current study, we wished to analyse if removal of Vglut2 expression already from mid-gestation of the mouse embryo would give rise to similar anxiolysis in the adult mouse.

METHODS: We produced transgenic mice lacking Vglut2 from mid-gestation and analysed their affective behaviour, including anxiety, when they had reached adulthood.

RESULTS: The transgenic mice lacking Vglut2 expression from mid-gestation showed certain signs of anxiolytic behaviour, but this phenotype was not as prominent as when Vglut2 was removed during adolescence.

CONCLUSION: Our results suggest that both embryonal and adolescent forebrain expression of Vglut2 normally contributes to balancing the level of anxiety. As the neurobiological basis for anxiety is similar across species, our results in mice may help improve the current understanding of the neurocircuitry of anxiety, and hence anxiolysis, also in humans.

National Category
Neurosciences
Identifiers
urn:nbn:se:uu:diva-287918 (URN)10.3109/03009734.2015.1032454 (DOI)000359819800002 ()25857802 (PubMedID)
Available from: 2016-04-26 Created: 2016-04-26 Last updated: 2018-01-10Bibliographically approved
Schweizer, N., Pupe, S., Arvidsson, E., Nordenankar, K., Smith-Anttila, C. J. A., Mahmoudi, S., . . . Wallén-Mackenzie, Å. (2014). Limiting glutamate transmission in a Vglut2-expressing subpopulation of the subthalamic nucleus is sufficient to cause hyperlocomotion. Proceedings of the National Academy of Sciences of the United States of America, 111(21), 7837-7842
Open this publication in new window or tab >>Limiting glutamate transmission in a Vglut2-expressing subpopulation of the subthalamic nucleus is sufficient to cause hyperlocomotion
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2014 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 111, no 21, p. 7837-7842Article in journal (Refereed) Published
Abstract [en]

The subthalamic nucleus (STN) is a key area of the basal ganglia circuitry regulating movement. We identified a subpopulation of neurons within this structure that coexpresses Vglut2 and Pitx2, and by conditional targeting of this subpopulation we reduced Vglut2 expression levels in the STN by 40%, leaving Pitx2 expression intact. This reduction diminished, yet did not eliminate, glutamatergic transmission in the substantia nigra pars reticulata and entopeduncular nucleus, two major targets of the STN. The knockout mice displayed hyperlocomotion and decreased latency in the initiation of movement while preserving normal gait and balance. Spatial cognition, social function, and level of impulsive choice also remained undisturbed. Furthermore, these mice showed reduced dopamine transporter binding and slower dopamine clearance in vivo, suggesting that Vglut2-expressing cells in the STN regulate dopaminergic transmission. Our results demonstrate that altering the contribution of a limited population within the STN is sufficient to achieve results similar to STN lesions and high-frequency stimulation, but with fewer side effects.

Keywords
Parkinson disease, deep brain stimulation, vesicular transporter, optogenetics, striatum
National Category
Neurosciences
Identifiers
urn:nbn:se:uu:diva-227717 (URN)10.1073/pnas.1323499111 (DOI)000336411300073 ()
Note

N.S. and S.P. contributed equally to this work.

Available from: 2014-06-30 Created: 2014-06-30 Last updated: 2018-01-11Bibliographically approved
Rajagopalan, A., Schweizer, N., Nordenankar, K., Jahan, S. N., Emilsson, L. & Wallen-Mackenzie, Å. (2014). Reduced Gene Expression Levels of Munc13-1 and Additional Components of the Presynaptic Exocytosis Machinery Upon Conditional Targeting of Vglut2 in the Adolescent Mouse. Synapse, 68(12), 624-633
Open this publication in new window or tab >>Reduced Gene Expression Levels of Munc13-1 and Additional Components of the Presynaptic Exocytosis Machinery Upon Conditional Targeting of Vglut2 in the Adolescent Mouse
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2014 (English)In: Synapse, ISSN 0887-4476, E-ISSN 1098-2396, Vol. 68, no 12, p. 624-633Article in journal (Refereed) Published
Abstract [en]

Presynaptic proteins orchestrate an intricate interplay of dynamic interactions in order to regulate quantal exocytosis of transmitter-filled vesicles, and their dysregulation might cause neurological and neuropsychiatric dysfunction. Mice carrying a spatiotemporal restriction in the expression of the Vesicular glutamate transporter 2 (Vglut2; aka Slc17a6) in the cortex, amygdala and hippocampal subiculum from the third postnatal week show a strong anxiolytic phenotype and certain behavioral correlates of schizophrenia. To further understand the molecular consequences of this targeted deletion of Vglut2, we performed an unbiased microarray analysis comparing gene expression levels in the subiculum of these conditional Vglut2 knockout mice (Vglut2(f/f;CamKII) cKO) to those in control littermates. Expression of Unc13C (Munc13-3), a member of the Unc/Munc family, previously shown to be important for glutamatergic transmission, was identified to be significantly down-regulated. Subsequent analysis by quantitative RT-PCR revealed a 50% down-regulation of Munc 13-1, the gene encoding the Unc/Munc subtype described as an essential component in the majority of glutamtergic synapses in the hippocampus. Genes encoding additional components of the presynaptic machinery were also found regulated, including Rab3A, RIM1, as well as Syntaxin1 and Synaptobrevin. Altered expression levels of these genes were further found in the amygdala and in the retrosplenial group of the cortex, additional regions in which Vglut2 was conditionally targeted. These findings suggest that expression levels of Vglut2 might be important for the maintenance of gene expression in the presynaptic machinery in the adult mouse brain. Synapse 68:624-633, 2014.

Keywords
amygdala, cortex, hippocampus, microarray, schizophrenia, Slc17a6, subiculum
National Category
Neurosciences
Identifiers
urn:nbn:se:uu:diva-237282 (URN)10.1002/syn.21776 (DOI)000343756900007 ()25139798 (PubMedID)
Available from: 2014-12-03 Created: 2014-12-01 Last updated: 2018-01-11Bibliographically approved
Nordenankar, K. (2012). Functional Analysis of the Vesicular Glutamate Transporter 2 in Specific Neuronal Circuits of the Brain. (Doctoral dissertation). Uppsala: Acta Universitatis Upsaliensis
Open this publication in new window or tab >>Functional Analysis of the Vesicular Glutamate Transporter 2 in Specific Neuronal Circuits of the Brain
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

A key issue in neuroscience is to determine the connection between neuronal circuits and behaviour. In the adult brain, all neuronal circuits include a glutamatergic component. Three proteins designated Vesicular glutamate transporter 1-3 (VGLUT1-3) possess the capability of packaging glutamate into presynaptic vesicles for release of glutamate at the nerve terminal.

The present study aimed at determining the role of VGLUT2 in neuronal circuits of higher brain function, emotion, and reward-pocessing. A conditional knockout (cKO) strategy was utilised, and three different mouse lines were produced to delete VGLUT2 in specific neuronal circuits in a temporally and spatially controlled manner. First, we produced a cKO mouse in which Vglut2 was deleted in specific subpopulations of the cortex, amygdala and hippocampus from preadolescence. This resulted in blunted aspects in cognitive, emotional and social behaviour in a schizophrenia-related phenotype. Furthermore, we showed a downstream effect of the targeted deletion on the dopaminergic system. In a subsequent analysis of the same cKO mice, we showed that female cKO mice were more affected their male counterparts, and we also found that female schizophrenia patients, but not male patients, had increased Vglut2 levels in the cortex.  Second, we produced and analysed cKO mice in which Vglut2 was deleted in the cortex, amygdala and hippocampus already from midgestation, and could show that this deletion affected emotional, but not cognitive, function. Third, we addressed the role of VGLUT2 in midbrain dopamine neurons by targeting Vglut2 specifically in these neurons. These cKO mice showed a blunted activational response to the psychostimulant amphetamine and increased operant self-administration of both sugar and cocaine reinforcers. Further, the cKO mice displayed strongly enhanced cocaine-seeking in response to cocaine-associated cues, a behaviour of relevance for addiction in humans.

In summary, this thesis work has addressed the role of the presynaptic glutamatergic neuron in different neuronal circuits and shown that the temporal and spatial distribution of VGLUT2 is of great significance for normal brain function.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2012. p. 53
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 748
Keywords
Addiction, amphetamine, affective behaviour, cocaine, cognitive behaviour, conditional knockout mouse, dopamine, operant self-administration, reward system, schizophrenia
National Category
Neurosciences
Research subject
Neuroscience
Identifiers
urn:nbn:se:uu:diva-170046 (URN)978-91-554-8297-8 (ISBN)
Public defence
2012-04-20, B22, BMC, Husargatan 3, 751 24 Uppsala, 09:15 (English)
Opponent
Supervisors
Available from: 2012-03-30 Created: 2012-03-07 Last updated: 2018-01-12Bibliographically approved
Fortin, G. M., Bourque, M.-J. -., Mendez, J. A., Leo, D., Nordenankar, K., Birgner, C., . . . Trudeau, L.-E. -. (2012). Glutamate corelease promotes growth and survival of midbrain dopamine neurons. Journal of Neuroscience, 32(48), 17477-17491
Open this publication in new window or tab >>Glutamate corelease promotes growth and survival of midbrain dopamine neurons
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2012 (English)In: Journal of Neuroscience, ISSN 0270-6474, E-ISSN 1529-2401, Vol. 32, no 48, p. 17477-17491Article in journal (Refereed) Published
Abstract [en]

Recent studies have proposed that glutamate corelease by mesostriatal dopamine (DA) neurons regulates behavioral activation by psychostimulants.How and when glutamate release by DA neurons might play this role remains unclear. Considering evidence for early expression of the type 2 vesicular glutamate transporter in mesencephalic DA neurons, we hypothesized that this cophenotype is particularly important during development. Using a conditional gene knock-out approach to selectively disrupt the Vglut2 gene in mouse DA neurons, we obtained in vitro and in vivo evidence for reduced growth and survival of mesencephalic DA neurons, associated with a decrease in the density of DA innervation in the nucleus accumbens, reduced activity-dependent DA release, and impaired motor behavior. These findings provide strong evidence for a functional role of the glutamatergic cophenotype in the development of mesencephalic DA neurons, opening new perspectives into the pathophysiology of neurodegenerative disorders involving the mesostriatal DA system.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-188124 (URN)10.1523/JNEUROSCI.1939-12.2012 (DOI)000311794700042 ()
Available from: 2012-12-13 Created: 2012-12-12 Last updated: 2017-12-06Bibliographically approved
Alsiö, J., Nordenankar, K., Arvidsson, E., Birgner, C., Mahmoudi, S., Halbout, B., . . . Wallén-Mackenzie, Å. (2011). Enhanced Sucrose and Cocaine Self-Administration and Cue-Induced Drug Seeking after Loss of VGLUT2 in Midbrain Dopamine Neurons in Mice. Journal of Neuroscience, 31(35), 12593-12603
Open this publication in new window or tab >>Enhanced Sucrose and Cocaine Self-Administration and Cue-Induced Drug Seeking after Loss of VGLUT2 in Midbrain Dopamine Neurons in Mice
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2011 (English)In: Journal of Neuroscience, ISSN 0270-6474, E-ISSN 1529-2401, Vol. 31, no 35, p. 12593-12603Article in journal (Refereed) Published
Abstract [en]

The mesostriatal dopamine (DA) system contributes to several aspects of responses to rewarding substances and is implicated in conditions such as drug addiction and eating disorders. A subset of DA neurons has been shown to express the type 2 Vesicular glutamate transporter (Vglut2) and may therefore corelease glutamate. In the present study, we analyzed mice with a conditional deletion of Vglut2 in DA neurons (Vglut2(f/f;DAT-Cre)) to address the functional significance of the glutamate-DA cophenotype for responses to cocaine and food reinforcement. Biochemical parameters of striatal DA function were also examined by using DA receptor autoradiography, immediate-early gene quantitative in situ hybridization after cocaine challenge, and DA-selective in vivo chronoamperometry. Mice in which Vglut2 expression had been abrogated in DA neurons displayed enhanced operant self-administration of both high-sucrose food and intravenous cocaine. Furthermore, cocaine seeking maintained by drug-paired cues was increased by 76%, showing that reward-dependent plasticity is perturbed in these mice. In addition, several lines of evidence suggest that adaptive changes occurred in both the ventral and dorsal striatum in the absence of VGLUT2: DA receptor binding was increased, and basal mRNA levels of the DA-induced early genes Nur77 and c-fos were elevated as after cocaine induction. Furthermore, in vivo challenge of the DA system by potassium-evoked depolarization revealed less DA release in both striatal areas. This study demonstrates that absence of VGLUT2 in DA neurons leads to perturbations of reward consumption as well as reward-associated memory, features of particular relevance for addictive-like behavior.

National Category
Neurosciences
Identifiers
urn:nbn:se:uu:diva-158895 (URN)10.1523/JNEUROSCI.2397-11.2011 (DOI)000294451900022 ()
Available from: 2011-09-19 Created: 2011-09-19 Last updated: 2018-01-12Bibliographically approved
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