uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Conditional genetic labeling of the Renshaw cell population for functional studies of motor control
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Developmental Genetics. (Formation and function of neuronal circuits)
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Developmental Genetics. (Formation and function of neuronal circuits)
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Developmental Genetics. (Formation and function of neuronal circuits)
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Developmental Genetics. (Formation and function of neuronal circuits)
Show others and affiliations
(English)Manuscript (preprint) (Other academic)
Abstract [en]

The Renshaw cells were among the first interneurons to be characterized in the mammalian spinal cord. Although the basic function of recurrent inhibition to motor neurons, as well as the Renshaw cell connectivity to other neurons have been thoroughly studied, the exact functional role of the Renshaw cells in motor control is still unknown. To further characterize the role of Renshaw cells in spinal cord circuitry, we searched for candidate genes useful in the Cre-loxP system. It has been reported that the mRNA expression of nicotinic cholinergic receptor alpha 2 (Chrna2) is found in a restricted number of cells at the ventral rim in adult rat and mouse spinal cord. In our own search for genes with distinct ventral expression, we noted a similar restricted Chrna2 mRNA expression pattern in the mouse spinal cord at postnatal day (P) 11 and during development at embryonic day 14.5. Based on the fact that the gene product is a cholinergic receptor and the pattern of expression, the neurons are predicted to be Renshaw cells. The possibility that these cells were motor neurons was excluded, since Chrna2 and Vesicular acetylcholine were not co-expressed at P11. To further study this cell population, we have generated a transgenic mouse expressing Cre recombinase (Cre) under the control of the Chrna2 promoter region. To visualize the Cre-expressing cells, the Chrna2-Cre transgenic mouse were bred with a reporter mouse expressing β-galactosidase (β-gal) in the nucleus after loxP excision. As expected, spinal cord β-gal immunoreactivity was observed in a limited number of ventrally located cells in the Cre-bearing offspring. Co-labeling of β-gal with calbindin-28K, a known marker for Renshaw cells, indicated that a majority of the calbindin positive cells were also β-gal positive at the ventral rim where calbindin is specific. In addition, β-gal positive cells without observable calbindin were also detected. It is conceivable that Chrna2 is expressed in additional cells apart from Renshaw cells or that a previously unidentified Renshaw cell subpopulation does not express calbindin. Nonetheless, a mouse with Cre-activity restricted to Chrna2-expressing cells opens the possibility to functionally study a limited population of spinal cord interneurons through genetic techniques, with the ambition to explore the specific role of Renshaw cells in spinal cord circuitry and motor control.

Keyword [en]
Renshaw cells, Spinal cord, Mouse, Nicotinic receptors, Cre recombinase
National Category
Cell and Molecular Biology Physiology Neurosciences
Research subject
Developmental Neurosciences; Molecular Biology
Identifiers
URN: urn:nbn:se:uu:diva-109917OAI: oai:DiVA.org:uu-109917DiVA: diva2:274578
Available from: 2009-10-29 Created: 2009-10-29 Last updated: 2012-02-24
In thesis
1. Studies of Spinal Motor Control Networks in Genetically Modified Mouse Models
Open this publication in new window or tab >>Studies of Spinal Motor Control Networks in Genetically Modified Mouse Models
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Spinal neurons are important in several aspects motor control. For example, the neurons essential for locomotor movements reside in the ventral spinal cord. In this thesis, different motor control functions are being related to neuronal populations defined by their common expression of a gene.

First, a targeted disruption of the gene for vesicular glutamate transporter 2 (Vglut2/ Slc17a6) is described. The mutant animals die at birth because of their inability to breathe. The neuronal network in the brainstem, responsible for inspiration, was shown to become non-functional by the targeted deletion of Vglut2. To our surprise, it was still possible to induce rhythmic activity with normal left/right alternation in spinal cords isolated from VGLUT2-null embryos. Inconsistent reports of Vglut1 expression in the spinal cord made us re-evaluate the Vglut1 and Vglut2 expressions. While Vglut2 expression was widespread in the spinal cord, Vglut1 expression was restricted to a few cells dorsal to the central canal.  Taken together, the data suggest that, glutamatergic signaling is mandatory to drive the bilateral breathing, but not needed for coordination of basal alternating spinal locomotor rhythm.

Next, a screen for genes with restricted ventral expression was made. Some of the genes found could be connected to the characteristics of specific neuronal cell populations. For example, fast motor neurons were shown to express the genes Calca and Chodl. Further, we found the Chrna2 expression selectively in putative Renshaw cells. It seems likely that the gene product, the alpha2 subunit of the nicotinergic receptor, could be linked to the unique connection of motor neurons to Renshaw cells. We used the Chrna2 promoter to drive expression of Cre recombinase in a transgenic mouse. The Cre activity was present in most neurons labeled with Renshaw cell markers, which should make it a useful tool for functional studies of this population. The studies presented here show how the genes expressed in subsets of neurons can be used to target populations of neurons for functional studies of neuronal systems.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2009. 45 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 497
Keyword
acetyl choline, central nervous system, central pattern generator, Cre recombinase, development, genetic screen, glutamate, interneuron, motor neuron, mouse, mouse genetics, movement, network, neuronal network, nicotinic receptors, physiology, Renshaw cell, rhythm, spinal cord, transmitter
National Category
Neurosciences Neurosciences Physiology Physiology Physiology
Research subject
Developmental Neurosciences
Identifiers
urn:nbn:se:uu:diva-109889 (URN)978-91-554-7654-0 (ISBN)
Public defence
2009-12-11, B22, BMC, Husarg 3, Uppsala, 09:00 (English)
Opponent
Supervisors
Available from: 2009-11-20 Created: 2009-10-29 Last updated: 2009-11-20Bibliographically approved

Open Access in DiVA

No full text

Authority records BETA

Gezelius, HenrikKullander, Klas

Search in DiVA

By author/editor
Gezelius, HenrikKullander, Klas
By organisation
Developmental Genetics
Cell and Molecular BiologyPhysiologyNeurosciences

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 888 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf