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Pahle J, Muhia M, Wagener RJ, Tippmann A, Bock HH, Graw J, Herz J, Staiger JF, Drakew A, Kneussel M, Rune GM, Frotscher M, Brunne B. Selective Inactivation of Reelin in Inhibitory Interneurons Leads to Subtle Changes in the Dentate Gyrus But Leaves Cortical Layering and Behavior Unaffected. Cereb Cortex 2021; 30:1688-1707. [PMID: 31667489 PMCID: PMC7132935 DOI: 10.1093/cercor/bhz196] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Reelin is an extracellular matrix protein, known for its dual role in neuronal migration during brain development and in synaptic plasticity at adult stages. During the perinatal phase, Reelin expression switches from Cajal-Retzius (CR) cells, its main source before birth, to inhibitory interneurons (IN), the main source of Reelin in the adult forebrain. IN-derived Reelin has been associated with schizophrenia and temporal lobe epilepsy; however, the functional role of Reelin from INs is presently unclear. In this study, we used conditional knockout mice, which lack Reelin expression specifically in inhibitory INs, leading to a substantial reduction in total Reelin expression in the neocortex and dentate gyrus. Our results show that IN-specific Reelin knockout mice exhibit normal neuronal layering and normal behavior, including spatial reference memory. Although INs are the major source of Reelin within the adult stem cell niche, Reelin from INs does not contribute substantially to normal adult neurogenesis. While a closer look at the dentate gyrus revealed some unexpected alterations at the cellular level, including an increase in the number of Reelin expressing CR cells, overall our data suggest that Reelin derived from INs is less critical for cortex development and function than Reelin expressed by CR cells.
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Affiliation(s)
- Jasmine Pahle
- Institute for Structural Neurobiology, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Mary Muhia
- Institute of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Robin J Wagener
- Neurology Clinic, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Anja Tippmann
- Institute for Structural Neurobiology, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany.,Department of Systems Neuroscience, Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology, University of Göttingen, 37075 Göttingen, Germany
| | - Hans H Bock
- Clinic of Gastroenterology and Hepatology, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany
| | - Janice Graw
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jochen F Staiger
- Institute for Neuroanatomy, University Medical Center Göttingen, Georg-August-University Göttingen, 37075 Göttingen, Germany
| | - Alexander Drakew
- Institute for Structural Neurobiology, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany.,Institute of Clinical Neuroanatomy, Faculty of Medicine, 60590 Frankfurt, Germany
| | - Matthias Kneussel
- Institute of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Gabriele M Rune
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Michael Frotscher
- Institute for Structural Neurobiology, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Bianka Brunne
- Institute for Structural Neurobiology, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany.,Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
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Yusifov R, Tippmann A, Staiger JF, Schlüter OM, Löwel S. Spine dynamics of PSD-95-deficient neurons in the visual cortex link silent synapses to structural cortical plasticity. Proc Natl Acad Sci U S A 2021; 118:e2022701118. [PMID: 33649238 PMCID: PMC7958355 DOI: 10.1073/pnas.2022701118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Critical periods (CPs) are time windows of heightened brain plasticity during which experience refines synaptic connections to achieve mature functionality. At glutamatergic synapses on dendritic spines of principal cortical neurons, the maturation is largely governed by postsynaptic density protein-95 (PSD-95)-dependent synaptic incorporation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors into nascent AMPA-receptor silent synapses. Consequently, in mouse primary visual cortex (V1), impaired silent synapse maturation in PSD-95-deficient neurons prevents the closure of the CP for juvenile ocular dominance plasticity (jODP). A structural hallmark of jODP is increased spine elimination, induced by brief monocular deprivation (MD). However, it is unknown whether impaired silent synapse maturation facilitates spine elimination and also preserves juvenile structural plasticity. Using two-photon microscopy, we assessed spine dynamics in apical dendrites of layer 2/3 pyramidal neurons (PNs) in binocular V1 during ODP in awake adult mice. Under basal conditions, spine formation and elimination ratios were similar between PSD-95 knockout (KO) and wild-type (WT) mice. However, a brief MD affected spine dynamics only in KO mice, where MD doubled spine elimination, primarily affecting newly formed spines, and caused a net reduction in spine density similar to what has been observed during jODP in WT mice. A similar increase in spine elimination after MD occurred if PSD-95 was knocked down in single PNs of layer 2/3. Thus, structural plasticity is dictated cell autonomously by PSD-95 in vivo in awake mice. Loss of PSD-95 preserves hallmark features of spine dynamics in jODP into adulthood, revealing a functional link of PSD-95 for experience-dependent synapse maturation and stabilization during CPs.
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Affiliation(s)
- Rashad Yusifov
- Department of Systems Neuroscience, Johann Friedrich Blumenbach Institut für Zoologie und Anthropologie, Universität Göttingen, D-37075 Göttingen, Germany
- Collaborative Research Center 889, Universität Göttingen, D-37075 Göttingen, Germany
- Campus Institute for Dynamics of Biological Networks, Universität Göttingen, D-37075 Göttingen, Germany
| | - Anja Tippmann
- Department of Systems Neuroscience, Johann Friedrich Blumenbach Institut für Zoologie und Anthropologie, Universität Göttingen, D-37075 Göttingen, Germany
- Campus Institute for Dynamics of Biological Networks, Universität Göttingen, D-37075 Göttingen, Germany
| | - Jochen F Staiger
- Collaborative Research Center 889, Universität Göttingen, D-37075 Göttingen, Germany
- Institute for Neuroanatomy, University Medical Center, Universität Göttingen, D-37075 Göttingen, Germany
| | - Oliver M Schlüter
- Collaborative Research Center 889, Universität Göttingen, D-37075 Göttingen, Germany
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Universität Göttingen, D-37075 Göttingen, Germany
| | - Siegrid Löwel
- Department of Systems Neuroscience, Johann Friedrich Blumenbach Institut für Zoologie und Anthropologie, Universität Göttingen, D-37075 Göttingen, Germany;
- Collaborative Research Center 889, Universität Göttingen, D-37075 Göttingen, Germany
- Campus Institute for Dynamics of Biological Networks, Universität Göttingen, D-37075 Göttingen, Germany
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Böhme MU, Fritzsch G, Tippmann A, Schlegel M, Berendonk TU. The complete mitochondrial genome of the Green Lizard Lacerta viridis viridis (Reptilia: Lacertidae) and its phylogenetic position within squamate reptiles. Gene 2007; 394:69-77. [PMID: 17391869 DOI: 10.1016/j.gene.2007.02.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Accepted: 02/09/2007] [Indexed: 10/23/2022]
Abstract
For the first time the complete mitochondrial genome was sequenced for a member of Lacertidae. Lacerta viridis viridis was sequenced in order to compare the phylogenetic relationships of this family to other reptilian lineages. Using the long-polymerase chain reaction (long PCR) we characterized a mitochondrial genome, 17,156 bp long showing a typical vertebrate pattern with 13 protein coding genes, 22 transfer RNAs (tRNA), two ribosomal RNAs (rRNA) and one major noncoding region. The noncoding region of L. v. viridis was characterized by a conspicuous 35 bp tandem repeat at its 5' terminus. A phylogenetic study including all currently available squamate mitochondrial sequences demonstrates the position of Lacertidae within a monophyletic squamate group. We obtained a narrow relationship of Lacertidae to Scincidae, Iguanidae, Varanidae, Anguidae, and Cordylidae. Although, the internal relationships within this group yielded only a weak resolution and low bootstrap support, the revealed relationships were more congruent with morphological studies than with recent molecular analyses.
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Affiliation(s)
- M U Böhme
- University of Leipzig, Biology II, Molecular Evolution and Animal Systematics, Talstrasse 33, 04103 Leipzig, Germany.
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