Emerging complexities in identity and function of glial connexins

Theis, Martin; Söhl, Goran; Eiberger, Jürgen; Willecke, Klaus

doi:10.1016/j.tins.2005.02.006

Cited by 187 publications

(140 citation statements)

References 58 publications

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“…In astrocytes, Cx30 and Cx43 are widely present in the adult brain, while Cx26 is expressed predominantly by subpial and subependymal astrocytes (16). While RG cells in the prenatal brain express Cx26 and Cx43 (8), no information is available about RG-like cells in the postnatal DG.…”

Section: Resultsmentioning

confidence: 99%

Connexin expression by radial glia-like cells is required for neurogenesis in the adult dentate gyrus

Kunze

Congreso

Hartmann

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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124

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Section: Resultsmentioning

confidence: 99%

Connexin expression by radial glia-like cells is required for neurogenesis in the adult dentate gyrus

Kunze

Congreso

Hartmann

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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124

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“…1, 3) as well as in the adult. Because in vivo astrocytic gap junctions are mainly composed by Cx43 and Cx30 (Nagy and Rash, 2000;Rouach et al, 2004;Theis et al, 2005), the present study was limited to the analysis of these two Cxs. Cx43 and Cx30 distribution was studied by confocal microscopy in coronal and tangential sections of the barrel field of mice at different ages (Fig.…”

Section: Expression Pattern Of Astrocytic Connexins In the Barrel Cortexmentioning

confidence: 99%

“…Indeed, in many brain regions and throughout animal life, gap junctional communication (GJC) is extensive and widespread between subpopulations of astrocytes (D'Ambrosio et al, 1998;Blomstrand et al, 2004;Wallraff et al, 2004). Such communicating pathways are provided by junctional proteins named connexins (Cxs), members of a multigenic family (Theis et al, 2005). In astrocytes, two of them prevail: Cx43 and Cx30 (Nagy and Rash, 2000).…”

Section: Introductionmentioning

confidence: 99%

Gap Junction-Mediated Astrocytic Networks in the Mouse Barrel Cortex

Houades¹,

Koulakoff²,

Ezan³

et al. 2008

J. Neurosci.

190

161

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The barrel field of the somatosensory cortex constitutes a well documented example of anatomofunctional compartmentalization and activity-dependent interaction between neurons and astrocytes. In astrocytes, intercellular communication through gap junction channels composed by connexin 43 and 30 underlies a network organization. Immunohistochemical and electrophysiological experiments were undertaken to determine the coupling properties of astrocyte networks in layer IV of the developing barrel cortex. The expression of both connexins was found to be enriched within barrels compared with septa and other cortical layers. Combination of dye-coupling experiments performed with biocytin and immunostaining with specific cell markers demonstrated that astrocytic networks do not involve neurons, oligodendrocytes or NG2 cells. The shape of dye coupling was oval in the barrel cortex whereas it was circular in layer IV outside the barrel field. Two-dimensional analysis of these coupling areas indicated that gap junctional communication was restricted from a barrel to its neighbor. Such enrichment of connexin expression and transversal restriction were not observed in a transgenic mouse lacking the barrel organization, whereas they were both observed in a double-transgenic mouse with restored barrels. Direct observation of sulforhodamine B spread indicated that astrocytes located between two barrels were either weakly or not coupled, whereas coupling within a barrel was oriented toward its center. These observations indicated a preferential orientation of coupling inside the barrels resulting from subpopulations of astrocytes with different coupling properties that contribute to shaping astrocytic networks. Such properties confine intercellular communication in astrocytes within a defined barrel as previously reported for excitatory neuronal circuits.

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“…Expression of Cx32 and Cx47 has been shown in oligodendrocytes studied in vitro and in vivo. 37 Distribution of Cx sybtypes in adult brain sections suggests differences in their subcellular localisation with Cx32 expression appearing first coincidentally with the start of myelination. 38 Expression of a gene reporter indicates that Cx29 is also present in oligodendrocytes in the white and grey matters.…”

Section: Intercellular Communication In Glia and Neuroprotectionmentioning

confidence: 99%

Glia: the fulcrum of brain diseases

et al. 2007

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Neuroglia represented by astrocytes, oligodendrocytes and microglial cells provide for numerous vital functions. Glial cells shape the micro-architecture of the brain matter; they are involved in information transfer by virtue of numerous plasmalemmal receptors and channels; they receive synaptic inputs; they are able to release 'glio'transmitters and produce long-range information exchange; finally they act as pluripotent neural precursors and some of them can even act as stem cells, which provide for adult neurogenesis. Recent advances in gliology emphasised the role of glia in the progression and handling of the insults to the nervous system. The brain pathology, is, to a very great extent, a pathology of glia, which, when falling to function properly, determines the degree of neuronal death, the outcome and the scale of neurological deficit. Glial cells are central in providing for brain homeostasis. As a result glia appears as a brain warden, and as such it is intrinsically endowed with two opposite features: it protects the nervous tissue as long as it can, but it also can rapidly assume the guise of a natural killer, trying to eliminate and seal the damaged area, to save the whole at the expense of the part. The sudden emergence of an intellect, and therefore a human being, which materialised only around a million years ago, remains the main mystery for our self-understanding. Similarly, we still do not know by which steps or transitions the human intellect emerged from the animal kingdom and where the fundamental difference between a man and an animal lies. According to the neuronal doctrine, which governs modern neuroscience since the beginning of the twentieth century, 1,2 the neurone is regarded as a basic information processing unit consisting of dendrites and axons with a unidirectional flow of information from the receiving dendrites via the integrating cell body to the terminal branches of the axon. Neuronal networks, connected through synaptic contacts, are generally considered as the substrate of our intellect.The number and size of neural cells increase with the size of the body and of the brain of mammals. This increasing quantity eventually has caused the generation of a new quality, the intellect. Rather amazingly, however, there is a relatively little difference in the morphology and physiology of neurones between humans and beasts; similarly the density of synaptic contacts in the brains of rodents and humans is more or less constant at around 1100-1300 millions/mm 3 . 3 On the contrary, evolution of the nervous system resulted in great changes in the second type of neural cells, the neuroglia. 4 Indeed, phylogenetic advance in brain complexity and capabilities coincided with a remarkable increase in the number of glial cells: in the rodent cortex the glial to neurone ratio is about 0.3 : 1, whereas in humans the same ratio is several times higher being B1.65:1, 5 while the total number of glial cells in the human brain is B10 (or even more) times larger than in lesser mammals. Astrocytes ...

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Emerging complexities in identity and function of glial connexins

Cited by 187 publications

References 58 publications

Connexin expression by radial glia-like cells is required for neurogenesis in the adult dentate gyrus

Connexin expression by radial glia-like cells is required for neurogenesis in the adult dentate gyrus

Gap Junction-Mediated Astrocytic Networks in the Mouse Barrel Cortex

Glia: the fulcrum of brain diseases

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