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Wilbrecht L, Lin WC, Callahan K, Bateson M, Myers K, Ross R. Experimental biology can inform our understanding of food insecurity. J Exp Biol 2024; 227:jeb246215. [PMID: 38449329 PMCID: PMC10949070 DOI: 10.1242/jeb.246215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Food insecurity is a major public health issue. Millions of households worldwide have intermittent and unpredictable access to food and this experience is associated with greater risk for a host of negative health outcomes. While food insecurity is a contemporary concern, we can understand its effects better if we acknowledge that there are ancient biological programs that evolved to respond to the experience of food scarcity and uncertainty, and they may be particularly sensitive to food insecurity during development. Support for this conjecture comes from common findings in several recent animal studies that have modeled insecurity by manipulating predictability of food access in various ways. Using different experimental paradigms in different species, these studies have shown that experience of insecure access to food can lead to changes in weight, motivation and cognition. Some of these studies account for changes in weight through changes in metabolism, while others observe increases in feeding and motivation to work for food. It has been proposed that weight gain is an adaptive response to the experience of food insecurity as 'insurance' in an uncertain future, while changes in motivation and cognition may reflect strategic adjustments in foraging behavior. Animal studies also offer the opportunity to make in-depth controlled studies of mechanisms and behavior. So far, there is evidence that the experience of food insecurity can impact metabolic efficiency, reproductive capacity and dopamine neuron synapses. Further work on behavior, the central and peripheral nervous system, the gut and liver, along with variation in age of exposure, will be needed to better understand the full body impacts of food insecurity at different stages of development.
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Affiliation(s)
- Linda Wilbrecht
- Department of Psychology, University of California, Berkeley, Berkeley, CA 94720-1650, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Wan Chen Lin
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Kathryn Callahan
- Psychiatric Research Institute of Montefiore and Einstein, Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Melissa Bateson
- Bioscience Institute, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK
| | - Kevin Myers
- Department of Psychology and Programs in Animal Behavior and Neuroscience, Bucknell University, Lewisburg, PA 17837, USA
| | - Rachel Ross
- Psychiatric Research Institute of Montefiore and Einstein, Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
- Department of Psychiatry, Montefiore Medical Center, Bronx, New York, NY 10467, USA
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2
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Anastasaki C, Gao Y, Gutmann DH. Neurons as stromal drivers of nervous system cancer formation and progression. Dev Cell 2023; 58:81-93. [PMID: 36693322 PMCID: PMC9883043 DOI: 10.1016/j.devcel.2022.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/24/2022] [Accepted: 12/27/2022] [Indexed: 01/24/2023]
Abstract
Similar to their pivotal roles in nervous system development, neurons have emerged as critical regulators of cancer initiation, maintenance, and progression. Focusing on nervous system tumors, we describe the normal relationships between neurons and other cell types relevant to normal nerve function, and discuss how disruptions of these interactions promote tumor evolution, focusing on electrical (gap junctions) and chemical (synaptic) coupling, as well as the establishment of new paracrine relationships. We also review how neuron-tumor communication contributes to some of the complications of cancer, including neuropathy, chemobrain, seizures, and pain. Finally, we consider the implications of cancer neuroscience in establishing risk for tumor penetrance and in the design of future anti-tumoral treatments.
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Affiliation(s)
- Corina Anastasaki
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Yunqing Gao
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - David H Gutmann
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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3
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Bauer S, Dittrich L, Kaczmarczyk L, Schleif M, Benfeitas R, Jackson WS. Translatome profiling in fatal familial insomnia implicates TOR signaling in somatostatin neurons. Life Sci Alliance 2022; 5:5/11/e202201530. [PMID: 36192034 PMCID: PMC9531780 DOI: 10.26508/lsa.202201530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 09/09/2022] [Accepted: 09/12/2022] [Indexed: 11/24/2022] Open
Abstract
Bauer and colleagues report that among the six neuron types studied, somatostatin neurons have an unexpectedly strong and similar response to two distinct genetic prion diseases before disease onset. Selective neuronal vulnerability is common in neurodegenerative diseases but poorly understood. In genetic prion diseases, including fatal familial insomnia (FFI) and Creutzfeldt–Jakob disease (CJD), different mutations in the Prnp gene manifest as clinically and neuropathologically distinct diseases. Here we report with electroencephalography studies that theta waves are mildly increased in 21 mo old knock-in mice modeling FFI and CJD and that sleep is mildy affected in FFI mice. To define affected cell types, we analyzed cell type–specific translatomes from six neuron types of 9 mo old FFI and CJD mice. Somatostatin (SST) neurons responded the strongest in both diseases, with unexpectedly high overlap in genes and pathways. Functional analyses revealed up-regulation of neurodegenerative disease pathways and ribosome and mitochondria biogenesis, and down-regulation of synaptic function and small GTPase-mediated signaling in FFI, implicating down-regulation of mTOR signaling as the root of these changes. In contrast, responses in glutamatergic cerebellar neurons were disease-specific. The high similarity in SST neurons of FFI and CJD mice suggests that a common therapy may be beneficial for multiple genetic prion diseases.
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Affiliation(s)
- Susanne Bauer
- Department of Biomedical and Clinical Sciences, Wallenberg Center for Molecular Medicine, Linköping University, Linköping, Sweden
| | - Lars Dittrich
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Lech Kaczmarczyk
- Department of Biomedical and Clinical Sciences, Wallenberg Center for Molecular Medicine, Linköping University, Linköping, Sweden.,German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Melvin Schleif
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Rui Benfeitas
- Department of Biochemistry and Biophysics, National Bioinformatics Infrastructure Sweden (NBIS), Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | - Walker S Jackson
- Department of Biomedical and Clinical Sciences, Wallenberg Center for Molecular Medicine, Linköping University, Linköping, Sweden .,German Center for Neurodegenerative Diseases, Bonn, Germany
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4
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Kosillo P, Ahmed KM, Aisenberg EE, Karalis V, Roberts BM, Cragg SJ, Bateup HS. Dopamine neuron morphology and output are differentially controlled by mTORC1 and mTORC2. eLife 2022; 11:e75398. [PMID: 35881440 PMCID: PMC9328766 DOI: 10.7554/elife.75398] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 07/08/2022] [Indexed: 02/07/2023] Open
Abstract
The mTOR pathway is an essential regulator of cell growth and metabolism. Midbrain dopamine neurons are particularly sensitive to mTOR signaling status as activation or inhibition of mTOR alters their morphology and physiology. mTOR exists in two distinct multiprotein complexes termed mTORC1 and mTORC2. How each of these complexes affect dopamine neuron properties, and whether they have similar or distinct functions is unknown. Here, we investigated this in mice with dopamine neuron-specific deletion of Rptor or Rictor, which encode obligatory components of mTORC1 or mTORC2, respectively. We find that inhibition of mTORC1 strongly and broadly impacts dopamine neuron structure and function causing somatodendritic and axonal hypotrophy, increased intrinsic excitability, decreased dopamine production, and impaired dopamine release. In contrast, inhibition of mTORC2 has more subtle effects, with selective alterations to the output of ventral tegmental area dopamine neurons. Disruption of both mTOR complexes leads to pronounced deficits in dopamine release demonstrating the importance of balanced mTORC1 and mTORC2 signaling for dopaminergic function.
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Affiliation(s)
- Polina Kosillo
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Kamran M Ahmed
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Erin E Aisenberg
- Helen Wills Neuroscience Institute, University of California, BerkeleyBerkeleyUnited States
| | - Vasiliki Karalis
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Bradley M Roberts
- Department of Physiology, Physiology, Anatomy and Genetics, University of OxfordOxfordUnited Kingdom
| | - Stephanie J Cragg
- Department of Physiology, Physiology, Anatomy and Genetics, University of OxfordOxfordUnited Kingdom
| | - Helen S Bateup
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- Helen Wills Neuroscience Institute, University of California, BerkeleyBerkeleyUnited States
- Chan Zuckerberg Biohub, San FranciscoSan FranciscoUnited States
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5
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Wu X, Sosunov AA, Lado W, Teoh JJ, Ham A, Li H, Al-Dalahmah O, Gill BJA, Arancio O, Schevon CA, Frankel WN, McKhann GM, Sulzer D, Goldman JE, Tang G. Synaptic hyperexcitability of cytomegalic pyramidal neurons contributes to epileptogenesis in tuberous sclerosis complex. Cell Rep 2022; 40:111085. [PMID: 35858542 PMCID: PMC9376014 DOI: 10.1016/j.celrep.2022.111085] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 02/15/2022] [Accepted: 06/22/2022] [Indexed: 11/27/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a developmental disorder associated with epilepsy, autism, and cognitive impairment. Despite inactivating mutations in the TSC1 or TSC2 genes and hyperactive mechanistic target of rapamycin (mTOR) signaling, the mechanisms underlying TSC-associated neurological symptoms remain incompletely understood. Here we generate a Tsc1 conditional knockout (CKO) mouse model in which Tsc1 inactivation in late embryonic radial glia causes social and cognitive impairment and spontaneous seizures. Tsc1 depletion occurs in a subset of layer 2/3 cortical pyramidal neurons, leading to development of cytomegalic pyramidal neurons (CPNs) that mimic dysplastic neurons in human TSC, featuring abnormal dendritic and axonal overgrowth, enhanced glutamatergic synaptic transmission, and increased susceptibility to seizure-like activities. We provide evidence that enhanced synaptic excitation in CPNs contributes to cortical hyperexcitability and epileptogenesis. In contrast, astrocytic regulation of synapse formation and synaptic transmission remains unchanged after late embryonic radial glial Tsc1 inactivation, and astrogliosis evolves secondary to seizures. Wu et al. demonstrate that Tsc1 inactivation in late embryonic radial glial cells (RGCs) produces cytomegalic pyramidal neurons that mimic TSC-like dysplastic neurons. They find that enhanced excitatory synaptic transmission in Tsc1-null cytomegalic pyramidal neurons contributes to cortical hyperexcitability and epileptogenesis.
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Affiliation(s)
- Xiaoping Wu
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Alexander A Sosunov
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Wudu Lado
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jia Jie Teoh
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Ahrom Ham
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Hongyu Li
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Osama Al-Dalahmah
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Brian J A Gill
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Ottavio Arancio
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA; The Taub Institute, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Catherine A Schevon
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Wayne N Frankel
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Guy M McKhann
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - David Sulzer
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Pharmacology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - James E Goldman
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; The Taub Institute, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Guomei Tang
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA.
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6
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A distinct D1-MSN subpopulation down-regulates dopamine to promote negative emotional state. Cell Res 2022; 32:139-156. [PMID: 34848869 PMCID: PMC8807621 DOI: 10.1038/s41422-021-00588-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 10/12/2021] [Indexed: 12/12/2022] Open
Abstract
Dopamine (DA) level in the nucleus accumbens (NAc) is critical for reward and aversion encoding. DA released from the ventral mesencephalon (VM) DAergic neurons increases the excitability of VM-projecting D1-dopamine receptor-expressing medium spiny neurons (D1-MSNs) in the NAc to enhance DA release and augment rewards. However, how such a DA positive feedback loop is regulated to maintain DA homeostasis and reward-aversion balance remains elusive. Here we report that the ventral pallidum (VP) projection of NAc D1-MSNs (D1NAc-VP) is inhibited by rewarding stimuli and activated by aversive stimuli. In contrast to the VM projection of D1-MSN (D1NAc-VM), activation of D1NAc-VP projection induces aversion, but not reward. D1NAc-VP MSNs are distinct from the D1NAc-VM MSNs, which exhibit conventional functions of D1-MSNs. Activation of D1NAc-VP projection stimulates VM GABAergic transmission, inhibits VM DAergic neurons, and reduces DA release into the NAc. Thus, D1NAc-VP and D1NAc-VM MSNs cooperatively control NAc dopamine balance and reward-aversion states.
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7
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Koene LM, Niggl E, Wallaard I, Proietti-Onori M, Rotaru DC, Elgersma Y. Identifying the temporal electrophysiological and molecular changes that contribute to TSC-associated epileptogenesis. JCI Insight 2021; 6:e150120. [PMID: 34877936 PMCID: PMC8675202 DOI: 10.1172/jci.insight.150120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 10/27/2021] [Indexed: 11/17/2022] Open
Abstract
Tuberous sclerosis complex (TSC), caused by heterozygous mutations in TSC1 or TSC2, frequently results in intractable epilepsy. Here, we made use of an inducible Tsc1-knockout mouse model, allowing us to study electrophysiological and molecular changes of Tsc1-induced epileptogenesis over time. We recorded from pyramidal neurons in the hippocampus and somatosensory cortex (L2/L3) and combined this with an analysis of transcriptome changes during epileptogenesis. Deletion of Tsc1 resulted in hippocampus-specific changes in excitability and adaptation, which emerged before seizure onset and progressed over time. All phenotypes were rescued after early treatment with rapamycin, an mTOR inhibitor. Later in epileptogenesis, we observed a hippocampal increase of excitation-to-inhibition ratio. These cellular changes were accompanied by dramatic transcriptional changes, especially after seizure onset. Most of these changes were rescued upon rapamycin treatment. Of the genes encoding ion channels or belonging to the Gene Ontology term action potential, 27 were differentially expressed just before seizure onset, suggesting a potential driving role in epileptogenesis. Our data highlight the complex changes driving epileptogenesis in TSC, including the changed expression of multiple ion channels. Our study emphasizes inhibition of the TSC/mTOR signaling pathway as a promising therapeutic approach to target epilepsy in patients with TSC.
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8
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Benthall KN, Cording KR, Agopyan-Miu AHCW, Wong CD, Chen EY, Bateup HS. Loss of Tsc1 from striatal direct pathway neurons impairs endocannabinoid-LTD and enhances motor routine learning. Cell Rep 2021; 36:109511. [PMID: 34380034 PMCID: PMC8404511 DOI: 10.1016/j.celrep.2021.109511] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 05/28/2021] [Accepted: 07/21/2021] [Indexed: 02/08/2023] Open
Abstract
Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder that often presents with psychiatric conditions, including autism spectrum disorder (ASD). ASD is characterized by restricted, repetitive, and inflexible behaviors, which may result from abnormal activity in striatal circuits that mediate motor learning and action selection. To test whether altered striatal activity contributes to aberrant motor behaviors in the context of TSC, we conditionally deleted Tsc1 from direct or indirect pathway striatal projection neurons (dSPNs or iSPNs, respectively). We find that dSPN-specific loss of Tsc1 impairs endocannabinoid-mediated long-term depression (eCB-LTD) at cortico-dSPN synapses and strongly enhances corticostriatal synaptic drive, which is not observed in iSPNs. dSPN-Tsc1 KO, but not iSPN-Tsc1 KO, mice show enhanced motor learning, a phenotype observed in several mouse models of ASD. These findings demonstrate that dSPNs are particularly sensitive to Tsc1 loss and suggest that enhanced corticostriatal activation may contribute to altered motor behaviors in TSC.
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Affiliation(s)
- Katelyn N Benthall
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Katherine R Cording
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | | | - Corinna D Wong
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Emily Y Chen
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Helen S Bateup
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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9
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Cording KR, Bateup HS. The Convergence of Two Signaling Pathways Within the Striatum Reveals Potential Mechanisms of Neuropsychiatric Disease. Biol Psychiatry 2021; 89:1027-1029. [PMID: 34016376 DOI: 10.1016/j.biopsych.2021.03.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 11/29/2022]
Affiliation(s)
- Katherine R Cording
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California
| | - Helen S Bateup
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California; Chan Zuckerberg Biohub, San Francisco, California.
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10
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Davatolhagh MF, Fuccillo MV. Neurexin1⍺ differentially regulates synaptic efficacy within striatal circuits. Cell Rep 2021; 34:108773. [PMID: 33626349 PMCID: PMC8071350 DOI: 10.1016/j.celrep.2021.108773] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 11/18/2020] [Accepted: 01/29/2021] [Indexed: 02/08/2023] Open
Abstract
Mutations in genes essential for synaptic function, such as the presynaptic adhesion molecule Neurexin1α (Nrxn1α), are strongly implicated in neuropsychiatric pathophysiology. As the input nucleus of the basal ganglia, the striatum integrates diverse excitatory projections governing cognitive and motor control, and its impairment may represent a recurrent pathway to disease. Here, we test the functional relevance of Nrxn1α in striatal circuits by employing optogenetic-mediated afferent recruitment of dorsal prefrontal cortical (dPFC) and parafascicular thalamic connections onto dorsomedial striatal (DMS) spiny projection neurons (SPNs). For dPFC-DMS circuits, we find decreased synaptic strength specifically onto indirect pathway SPNs in both Nrxn1α+/- and Nrxn1α-/- mice, driven by reductions in neurotransmitter release. In contrast, thalamic excitatory inputs to DMS exhibit relatively normal excitatory synaptic strength despite changes in synaptic N-methyl-D-aspartate receptor (NMDAR) content. These findings suggest that dysregulation of Nrxn1α modulates striatal function in an input- and target-specific manner.
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Affiliation(s)
- M Felicia Davatolhagh
- Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marc V Fuccillo
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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11
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Rial D, Puighermanal E, Chazalon M, Valjent E, Schiffmann SN, de Kerchove d'Exaerde A. Mammalian Target of Rapamycin-RhoA Signaling Impairments in Direct Striatal Projection Neurons Induce Altered Behaviors and Striatal Physiology in Mice. Biol Psychiatry 2020; 88:945-954. [PMID: 32711953 DOI: 10.1016/j.biopsych.2020.05.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 05/18/2020] [Accepted: 05/21/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND As an integrator of molecular pathways, mTOR (mammalian target of rapamycin) has been associated with diseases including neurodevelopmental, psychiatric, and neurodegenerative disorders such as autism spectrum disorder, schizophrenia, and Huntington's disease. An important brain area involved in all these diseases is the striatum. However, the mechanisms behind how mTOR is involved in striatal physiology and its relative role in distinct neuronal populations in these striatal-related diseases still remain to be clarified. METHODS Using Drd1-Cre mTOR-conditional knockout male mice, we combined behavioral, biochemical, electrophysiological, and morphological analysis aiming to untangle the role of mTOR in direct pathway striatal projection neurons and how this would impact on striatal physiology. RESULTS Our results indicate deep behavioral changes in absence of mTOR in Drd1-expressing neurons such as decreased spontaneous locomotion, impaired social interaction, and decreased marble-burying behavior. These alterations were accompanied by a Kv1.1-induced increase in the fast phase of afterhyperpolarization and coincident decreased distal spine density in striatal direct pathway striatal projection neurons. The physiological changes were mechanistically independent of protein synthesis but sensitive to pharmacological blockade of transforming protein RhoA activity. CONCLUSIONS These results identify mTOR signaling as an important regulator of striatal functions through an intricate mechanism involving RhoA and culminating in Kv1.1 overfunction, which could be targeted to treat striatal-related monogenic disorders associated with the mTOR signaling pathway.
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Affiliation(s)
- Daniel Rial
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Emma Puighermanal
- Institut de Génétique Foncionnelle (IGF), Centre National de la Recherche Scientifique (CNRS), (Institut National de la Santé et de la Recherche Médicale (INSERM), University of Montpellier, Montpellier, France
| | - Marine Chazalon
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Emmanuel Valjent
- Institut de Génétique Foncionnelle (IGF), Centre National de la Recherche Scientifique (CNRS), (Institut National de la Santé et de la Recherche Médicale (INSERM), University of Montpellier, Montpellier, France
| | - Serge N Schiffmann
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Alban de Kerchove d'Exaerde
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium.
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12
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Lin WC, Delevich K, Wilbrecht L. A role for adaptive developmental plasticity in learning and decision making. Curr Opin Behav Sci 2020; 36:48-54. [DOI: 10.1016/j.cobeha.2020.07.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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13
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Kapur M, Ganguly A, Nagy G, Adamson SI, Chuang JH, Frankel WN, Ackerman SL. Expression of the Neuronal tRNA n-Tr20 Regulates Synaptic Transmission and Seizure Susceptibility. Neuron 2020; 108:193-208.e9. [PMID: 32853550 DOI: 10.1016/j.neuron.2020.07.023] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 06/07/2020] [Accepted: 07/19/2020] [Indexed: 12/31/2022]
Abstract
The mammalian genome has hundreds of nuclear-encoded tRNAs, but the contribution of individual tRNA genes to cellular and organismal function remains unknown. Here, we demonstrate that mutations in a neuronally enriched arginine tRNA, n-Tr20, increased seizure threshold and altered synaptic transmission. n-Tr20 expression also modulated seizures caused by an epilepsy-linked mutation in Gabrg2, a gene encoding a GABAA receptor subunit. Loss of n-Tr20 altered translation initiation by activating the integrated stress response and suppressing mTOR signaling, the latter of which may contribute to altered neurotransmission in mutant mice. Deletion of a highly expressed isoleucine tRNA similarly altered these signaling pathways in the brain, suggesting that regulation of translation initiation is a conserved response to tRNA loss. Our data indicate that loss of a single member of a tRNA family results in multiple cellular phenotypes, highlighting the disease-causing potential of tRNA mutations.
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Affiliation(s)
- Mridu Kapur
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Archan Ganguly
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Gabor Nagy
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Scott I Adamson
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA; Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn Health, Farmington, CT 06030, USA
| | - Jeffrey H Chuang
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Wayne N Frankel
- Institute for Genomic Medicine, Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Susan L Ackerman
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA.
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14
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Feliciano DM. The Neurodevelopmental Pathogenesis of Tuberous Sclerosis Complex (TSC). Front Neuroanat 2020; 14:39. [PMID: 32765227 PMCID: PMC7381175 DOI: 10.3389/fnana.2020.00039] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 06/10/2020] [Indexed: 12/22/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a model disorder for understanding brain development because the genes that cause TSC are known, many downstream molecular pathways have been identified, and the resulting perturbations of cellular events are established. TSC, therefore, provides an intellectual framework to understand the molecular and biochemical pathways that orchestrate normal brain development. The TSC1 and TSC2 genes encode Hamartin and Tuberin which form a GTPase activating protein (GAP) complex. Inactivating mutations in TSC genes (TSC1/TSC2) cause sustained Ras homologue enriched in brain (RHEB) activation of the mammalian isoform of the target of rapamycin complex 1 (mTORC1). TOR is a protein kinase that regulates cell size in many organisms throughout nature. mTORC1 inhibits catabolic processes including autophagy and activates anabolic processes including mRNA translation. mTORC1 regulation is achieved through two main upstream mechanisms. The first mechanism is regulation by growth factor signaling. The second mechanism is regulation by amino acids. Gene mutations that cause too much or too little mTORC1 activity lead to a spectrum of neuroanatomical changes ranging from altered brain size (micro and macrocephaly) to cortical malformations to Type I neoplasias. Because somatic mutations often underlie these changes, the timing, and location of mutation results in focal brain malformations. These mutations, therefore, provide gain-of-function and loss-of-function changes that are a powerful tool to assess the events that have gone awry during development and to determine their functional physiological consequences. Knowledge about the TSC-mTORC1 pathway has allowed scientists to predict which upstream and downstream mutations should cause commensurate neuroanatomical changes. Indeed, many of these predictions have now been clinically validated. A description of clinical imaging and histochemical findings is provided in relation to laboratory models of TSC that will allow the reader to appreciate how human pathology can provide an understanding of the fundamental mechanisms of development.
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Affiliation(s)
- David M Feliciano
- Department of Biological Sciences, Clemson University, Clemson, SC, United States
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15
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Kosillo P, Doig NM, Ahmed KM, Agopyan-Miu AHCW, Wong CD, Conyers L, Threlfell S, Magill PJ, Bateup HS. Tsc1-mTORC1 signaling controls striatal dopamine release and cognitive flexibility. Nat Commun 2019; 10:5426. [PMID: 31780742 PMCID: PMC6882901 DOI: 10.1038/s41467-019-13396-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 11/07/2019] [Indexed: 11/13/2022] Open
Abstract
Tuberous Sclerosis Complex (TSC) is a neurodevelopmental disorder caused by mutations in TSC1 or TSC2, which encode proteins that negatively regulate mTOR complex 1 (mTORC1). TSC is associated with significant cognitive, psychiatric, and behavioral problems, collectively termed TSC-Associated Neuropsychiatric Disorders (TAND), and the cell types responsible for these manifestations are largely unknown. Here we use cell type-specific Tsc1 deletion to test whether dopamine neurons, which modulate cognitive, motivational, and affective behaviors, are involved in TAND. We show that loss of Tsc1 and constitutive activation of mTORC1 in dopamine neurons causes somatodendritic hypertrophy, reduces intrinsic excitability, alters axon terminal structure, and impairs striatal dopamine release. These perturbations lead to a selective deficit in cognitive flexibility, preventable by genetic reduction of the mTOR-binding protein Raptor. Our results establish a critical role for Tsc1-mTORC1 signaling in setting the functional properties of dopamine neurons, and indicate that dopaminergic dysfunction may contribute to cognitive inflexibility in TSC.
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Affiliation(s)
- Polina Kosillo
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Natalie M Doig
- Medical Research Council Brain Network Dynamics Unit, University of Oxford, Oxford, OX1 3TH, UK
| | - Kamran M Ahmed
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
| | | | - Corinna D Wong
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Lisa Conyers
- Medical Research Council Brain Network Dynamics Unit, University of Oxford, Oxford, OX1 3TH, UK
| | - Sarah Threlfell
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, OX1 3QX, UK
| | - Peter J Magill
- Medical Research Council Brain Network Dynamics Unit, University of Oxford, Oxford, OX1 3TH, UK
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, OX1 3QX, UK
| | - Helen S Bateup
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, 94720, USA.
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, 94720, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA.
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Krajeski RN, Macey-Dare A, van Heusden F, Ebrahimjee F, Ellender TJ. Dynamic postnatal development of the cellular and circuit properties of striatal D1 and D2 spiny projection neurons. J Physiol 2019; 597:5265-5293. [PMID: 31531863 PMCID: PMC6900874 DOI: 10.1113/jp278416] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 09/04/2019] [Indexed: 12/15/2022] Open
Abstract
KEY POINTS Imbalances in the activity of the D1-expressing direct pathway and D2-expressing indirect pathway striatal projection neurons (SPNs) are thought to contribute to many basal ganglia disorders, including early-onset neurodevelopmental disorders such as obsessive-compulsive disorder, attention deficit hyperactivity disorder and Tourette's syndrome. This study provides the first detailed quantitative investigation of development of D1 and D2 SPNs, including their cellular properties and connectivity within neural circuits, during the first postnatal weeks. This period is highly dynamic with many properties changing, but it is possible to make three main observations: many aspects of D1 and D2 SPNs progressively mature in parallel; there are notable exceptions when they diverge; and many of the defining properties of mature striatal SPNs and circuits are already established by the first and second postnatal weeks, suggesting guidance through intrinsic developmental programmes. These findings provide an experimental framework for future studies of striatal development in both health and disease. ABSTRACT Many basal ganglia neurodevelopmental disorders are thought to result from imbalances in the activity of the D1-expressing direct pathway and D2-expressing indirect pathway striatal projection neurons (SPNs). Insight into these disorders is reliant on our understanding of normal D1 and D2 SPN development. Here we provide the first detailed study and quantification of the striatal cellular and circuit changes occurring for both D1 and D2 SPNs in the first postnatal weeks using in vitro whole-cell patch-clamp electrophysiology. Characterization of their intrinsic electrophysiological and morphological properties, the excitatory long-range inputs coming from cortex and thalamus, as well their local gap junction and inhibitory synaptic connections reveals this period to be highly dynamic with numerous properties changing. However it is possible to make three main observations. Firstly, many aspects of SPNs mature in parallel, including intrinsic membrane properties, increases in dendritic arbours and spine densities, general synaptic inputs and expression of specific glutamate receptors. Secondly, there are notable exceptions, including a transient stronger thalamic innervation of D2 SPNs and stronger cortical NMDA receptor-mediated inputs to D1 SPNs, both in the second postnatal week. Thirdly, many of the defining properties of mature D1 and D2 SPNs and striatal circuits are already established by the first and second postnatal weeks, including different electrophysiological properties as well as biased local inhibitory connections between SPNs, suggesting this is guided through intrinsic developmental programmes. Together these findings provide an experimental framework for future studies of D1 and D2 SPN development in health and disease.
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Affiliation(s)
- Rohan N Krajeski
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
| | - Anežka Macey-Dare
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
| | - Fran van Heusden
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
| | - Farid Ebrahimjee
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
| | - Tommas J Ellender
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
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Li W, Su D, Zhai Q, Chi H, She X, Gao X, Wang K, Yang H, Wang R, Cui B. Proteomes analysis reveals the involvement of autophagy in AD-like neuropathology induced by noise exposure and ApoE4. ENVIRONMENTAL RESEARCH 2019; 176:108537. [PMID: 31228807 DOI: 10.1016/j.envres.2019.108537] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/12/2019] [Accepted: 06/14/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Noise is one of the most important environmental health hazards for humans. Environmental noise or apolipoprotein ε4 (ApoE4) can cause typical Alzheimer's disease (AD)-like pathological changes, which is characterized by progressive cognitive decline and neurodegenerative lesions. Gene-environment interactions may accelerate cognitive decline and increase AD risk. However, there is limited experimental evidence regarding the underlying mechanisms of noise-ApoE4 interactions and AD, which may be closely related to AD development. METHODS In this study, we investigated the combined effects of chronic noise exposure and the ApoE4 gene activation on hippocampus by using proteomics and differentially expressed proteins were found through performed gene ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. In addition, we assessed the changes in adult hippocampal neurogenesis and potential underlying mechanism for AD-like neuropathology. RESULTS Relative to control rats, combined exposure of noise and ApoE4 synergistically increased the characteristic pathological amyloid β-protein of AD-like neuropathology changes in hippocampus. The research identifies a total of 4147 proteins and 15 differentially expressed proteins in hippocampus. Furthermore, comparison of several of the diverse key pathways studied (e.g., PI3K/AKT, insulin, calpain-CDK5, and mammalian target of rapamycin (mTOR) signaling pathways) help to articulate the different mechanisms involved in combined effects of noise and ApoE4 on AD-like pathology. We verified four selected proteins, namely, eukaryotic translation elongation factor 1 epsilon 1, glycine amidinotransferase, nucleoredoxin, and tuberous sclerosis 1 proteins. Validation data shows significant effects of chronic noise and ApoE4 on the expression of four selected proteins, eukaryotic translation elongation factor 1 epsilon 1, glycine amidinotransferase, nucleoredoxin, and tuberous sclerosis 1 proteins, and mTOR and autophagy-related proteins, which share significant interaction effect of chronic noise and ApoE4. CONCLUSION Gene-environment interactions between chronic noise and ApoE4 activate the mTOR signaling, decrease autophagy, and facilitate AD-like changes in the hippocampus. Thus, our findings may help elucidate the role of gene-environment interactions in AD development.
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Affiliation(s)
- Wenlong Li
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China; School of Public Health and Management, Weifang Medical University, Weifang, China
| | - Donghong Su
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China; Shandong Academy of Occupational Health and Occupational Medicine, Shandong Academy of Medical Sciences, Jinan, China
| | - Qingfeng Zhai
- School of Public Health and Management, Weifang Medical University, Weifang, China
| | - Huimin Chi
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China; School of Public Health and Management, Weifang Medical University, Weifang, China
| | - Xiaojun She
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Xiujie Gao
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Kun Wang
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Honglian Yang
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Rui Wang
- Shandong Academy of Occupational Health and Occupational Medicine, Shandong Academy of Medical Sciences, Jinan, China
| | - Bo Cui
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China.
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18
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Koene LMC, van Grondelle SE, Proietti Onori M, Wallaard I, Kooijman NHRM, van Oort A, Schreiber J, Elgersma Y. Effects of antiepileptic drugs in a new TSC/mTOR-dependent epilepsy mouse model. Ann Clin Transl Neurol 2019; 6:1273-1291. [PMID: 31353861 PMCID: PMC6649373 DOI: 10.1002/acn3.50829] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 06/05/2019] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE An epilepsy mouse model for Tuberous Sclerosis Complex (TSC) was developed and validated to investigate the mechanisms underlying epileptogenesis. Furthermore, the possible antiepileptogenic properties of commonly used antiepileptic drugs (AEDs) and new compounds were assessed. METHODS Tsc1 deletion was induced in CAMK2A-expressing neurons of adult mice. The antiepileptogenic properties of commonly used AEDs and inhibitors of the mTOR pathways were assessed by EEG recordings and by molecular read outs. RESULTS Mice developed epilepsy in a narrow time window (10 ± 2 days) upon Tsc1 gene deletion. Seizure frequency but not duration increased over time. Seizures were lethal within 18 days, were unpredictable, and did not correlate to seizure onset, length or frequency, reminiscent of sudden unexpected death in epilepsy (SUDEP). Tsc1 gene deletion resulted in a strong activation of the mTORC1 pathway, and both epileptogenesis and lethality could be entirely prevented by RHEB1 gene deletion or rapamycin treatment. However, other inhibitors of the mTOR pathway such as AZD8055 and PF4708671 were ineffective. Except for ketogenic diet, none of commonly used AEDs showed an effect on mTORC1 activity. Vigabatrin and ketogenic diet treatment were able to significantly delay seizure onset. In contrast, survival was shortened by lamotrigine. INTERPRETATION This novel Tsc1 mouse model is highly suitable to assess the efficacy of antiepileptic and -epileptogenic drugs to treat mTORC1-dependent epilepsy. Additionally, it allows us to study the mechanisms underlying mTORC1-mediated epileptogenesis and SUDEP. We found that early treatment with vigabatrin was not able to prevent epilepsy, but significantly delayed seizure onset.
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Affiliation(s)
- Linda M. C. Koene
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Saskia E. van Grondelle
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Martina Proietti Onori
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Ilse Wallaard
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Nathalie H. R. M. Kooijman
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Annabel van Oort
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Jadwiga Schreiber
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Ype Elgersma
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
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Lee Y, Han PL. Early-Life Stress in D2 Heterozygous Mice Promotes Autistic-like Behaviors through the Downregulation of the BDNF-TrkB Pathway in the Dorsal Striatum. Exp Neurobiol 2019; 28:337-351. [PMID: 31308794 PMCID: PMC6614072 DOI: 10.5607/en.2019.28.3.337] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/30/2019] [Accepted: 06/05/2019] [Indexed: 12/12/2022] Open
Abstract
A number of specific genetic variants including gene mutations and single nucleotide variations have been identified in genomewide association studies of autism spectrum disorder (ASD). ASD phenotypes in individuals carrying specific genetic variations are manifest mostly in a heterozygous state. Furthermore, individuals with most genetic variants show incomplete penetrance and phenotypic variability, suggesting that non-genetic factors are also involved in developing ASD. However, the mechanisms of how genetic and environmental factors interactively promote ASD are not clearly understood. In the present study, we investigated whether early-life stress (ELS) in D2 dopamine receptor heterozygous knockout (D2+/−) mice induces ASD-like symptoms. To address that, we exposed D2 heterozygous pups to maternal separation stress for 3 h daily for 13 days beginning on postnatal day 2. D2+/− adult mice that had experienced ELS exhibited impaired sociability in the three-chamber test and home-cage social interaction test and increased grooming behavior, whereas wildtype littermates exposed to ELS did not show those phenotypes. ELS-exposed D2+/− mice had decreased levels of BDNF, TrkB, phospho-ERK1/2 and phospho-CREB in the dorsal striatum. Administration of the TrkB agonist 7,8-dihydroxyflavone (7,8-DHF) to ELS-exposed D2+/− mice rescued the sociability deficits and repetitive behavior. In contrast, behavioral rescue by 7,8-DHF in ELS-exposed D2+/− mice was blocked when TrkB expression in the dorsal striatum was locally inhibited by the injection of TrkB-siRNA. Together, our results suggest that the interaction between ELS and defective D2 gene function promotes autistic-like behaviors by downregulating the BDNF-TrkB pathway in the dorsal striatum.
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Affiliation(s)
- Yunjin Lee
- Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul 03760, Korea
| | - Pyung-Lim Han
- Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul 03760, Korea.,Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
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Lee Y, Kim H, Han PL. Striatal Inhibition of MeCP2 or TSC1 Produces Sociability Deficits and Repetitive Behaviors. Exp Neurobiol 2018; 27:539-549. [PMID: 30636904 PMCID: PMC6318563 DOI: 10.5607/en.2018.27.6.539] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 11/15/2018] [Accepted: 11/19/2018] [Indexed: 01/06/2023] Open
Abstract
Autism spectrum disorder (ASD) is a heterogeneous group of neurobehavioral disorders characterized by the two core domains of behavioral deficits, including sociability deficits and stereotyped repetitive behaviors. It is not clear whether the core symptoms of ASD are produced by dysfunction of the overall neural network of the brain or that of a limited brain region. Recent studies reported that excessive glutamatergic or dopaminergic inputs in the dorsal striatum induced sociability deficits and repetitive behaviors. These findings suggest that the dorsal striatum plays a crucial role in autistic-like behaviors. The present study addresses whether functional deficits of well-known ASD-related genes in the dorsal striatum also produce ASD core symptoms. This study also examines whether these behavioral changes can be modulated by rebalancing glutamate and/or dopamine receptor activity in the dorsal striatum. First, we found that the siRNA-mediated inhibition of Shank3, Nlgn3, Fmr1, Mecp2, or Tsc1 in the dorsal striatum produced mild to severe behavioral changes in sociability, cognition, and/or repetitive behaviors. The knockdown effects of Mecp2 and Tsc1 on behavioral changes were the most prominent. Next, we demonstrated that behavioral changes induced by striatal inhibition of MeCP2 and TSC1 were rescued by D-cycloserine (an NMDA agonist), fenobam (an mGluR5 antagonist), SCH23390 (a D1 antagonist), and/or ecopipam (a D1 partial antagonist), pharmacological drugs that are known to regulate ASD-like symptoms in animal models. Collectively, these results suggest that the dorsal striatum is a critical brain region that, when dysfunctional, produces the core symptoms of ASD.
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Affiliation(s)
- Yunjin Lee
- Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul 03760, Korea
| | - Hannah Kim
- Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul 03760, Korea
| | - Pyung-Lim Han
- Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul 03760, Korea.,Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
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