scholarly journals Signalling through AMPA receptors on oligodendrocyte precursors promotes myelination by enhancing oligodendrocyte survival

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Eleni Kougioumtzidou ◽  
Takahiro Shimizu ◽  
Nicola B Hamilton ◽  
Koujiro Tohyama ◽  
Rolf Sprengel ◽  
...  
Keyword(s):  
Central Nervous System ◽  
White Matter ◽  
Ampa Receptors ◽  
Information Transfer ◽  
Average Length ◽  
Subcortical White Matter ◽  
Myelin Sheaths ◽  
The Central Nervous System ◽  
Per Se ◽  
Oligodendrocyte Precursors

Myelin, made by oligodendrocytes, is essential for rapid information transfer in the central nervous system. Oligodendrocyte precursors (OPs) receive glutamatergic synaptic input from axons but how this affects their development is unclear. Murine OPs in white matter express AMPA receptor (AMPAR) subunits GluA2, GluA3 and GluA4. We generated mice in which OPs lack both GluA2 and GluA3, or all three subunits GluA2/3/4, which respectively reduced or abolished AMPAR-mediated input to OPs. In both double- and triple-knockouts OP proliferation and number were unchanged but ~25% fewer oligodendrocytes survived in the subcortical white matter during development. In triple knockouts, this shortfall persisted into adulthood. The oligodendrocyte deficit resulted in ~20% fewer myelin sheaths but the average length, number and thickness of myelin internodes made by individual oligodendrocytes appeared normal. Thus, AMPAR-mediated signalling from active axons stimulates myelin production in developing white matter by enhancing oligodendrocyte survival, without influencing myelin synthesis per se.

scholarly journals Biology of the repair of central nervous system demyelinated lesions: an appraisal

1996 ◽  
Vol 54 (2) ◽  
pp. 331-334 ◽  
Author(s):  
L. A. V Peireira ◽  
M. A. Cruz-Höfling ◽  
M. S. J. Dertkigil ◽  
D. L. Graça
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Schwann Cells ◽  
Demyelinating Disease ◽  
Experimental Models ◽  
Primitive Cell ◽  
Marked Influence ◽  
Myelin Sheaths ◽  
Human Material ◽  
The Central Nervous System

The integrity of myelin sheaths is maintained by oligodendrocytes and Schwann cells respectively in the central nervous system (CNS) and in the peripheral nervous system. The process of demyelination consisting of the withdrawal of myelin sheaths from their axons is a characteristic feature of multiple sclerosis, the most common human demyelinating disease. Many experimental models have been designed to study the biology of demyelination and remyelination (repair of the lost myelin) in the CNS, due to the difficulties in studying human material. In the ethidium bromide (an intercalating gliotoxic drug) model of demyelination, CNS remyelination may be carried out by surviving oligodendrocytes and/or by cells differentiated from the primitive cell lines or either by Schwann cells that invade the CNS. However, some factors such as the age of the experimental animals, intensity and time of exposure to the intercalating chemical and the topography of the lesions have marked influence on the repair of the tissue.

Neurotrophins and theirtrk receptors in cultured cells of the glial lineage and in white matter of the central nervous system

1995 ◽  
Vol 6 (4) ◽  
pp. 237-248 ◽  
Author(s):  
Daniele F. Condorelli ◽  
Tuija Salin ◽  
Paola Dell’Albani ◽  
Giuseppa Mudò ◽  
Massimo Corsaro ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
White Matter ◽  
Cultured Cells ◽  
The Central Nervous System ◽  
Glial Lineage

Comparison of the Effects of Convulsant and Depressant Barbiturate Stereoisomers on AMPA-type Glutamate Receptors

1999 ◽  
Vol 90 (6) ◽  
pp. 1704-1713. ◽  
Author(s):  
Yoshinori Kamiya ◽  
Tomio Andoh ◽  
Ryosuke Furuya ◽  
Satoshi Hattori ◽  
Itaru Watanabe ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Glutamate Receptors ◽  
Ampa Receptor ◽  
Ampa Receptors ◽  
Dependent Manner ◽  
Induced Current ◽  
Gaba A ◽  
The Central Nervous System

Background Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptors mediate fast excitatory synaptic transmission in the central nervous system. Although barbiturates have been shown to suppress the AMPA receptor-mediated responses, it is unclear whether this effect contributes to the anesthetic action of barbiturates. The authors compared the effects of depressant [R(-)] and convulsant [S(+)] stereoisomers of 1-methyl-5-phenyl-5-propyl barbituric acid (MPPB) on the AMPA and gamma-aminobutyric acid type A (GABA(A)) receptor-mediated currents to determine if the inhibitory effects on AMPA receptors correlate to the in vivo effects of the isomers. Method The authors measured whole-cell currents in the rat cultured cortical neuron at holding potential of -60 mV. Kainate 500 microM was applied as the agonist for AMPA receptors. Thiopental (3-300 microM), R(-)-MPPB or S(+)-MPPB (100-1,000 microM) was coapplied with kainate under the condition in which the GABA(A) receptor-mediated current was blocked. Effects of MPPB isomers on the current elicited by GABA 1 microM were studied in the separate experiments. Results Thiopental inhibited the kainate-induced current reversibly and in a dose-dependent manner, with a concentration for 50% inhibition of 49.3 microM. Both R(-)-MPPB and S(+)-MPPB inhibited the kainate-induced current with a little stereoselectivity. R(-)-MPPB was slightly but significantly more potent than S(+)-MPPB. In contrast, R(-)-MPPB enhanced but S(+)-MPPB reduced the GABA-induced current. Conclusions Both convulsant and depressant stereoisomers of the barbiturate inhibited the AMPA receptor-mediated current despite of their opposite effects on the central nervous system in vivo. Although thiopental exhibited a considerable inhibition of AMPA receptors, the results suggest that the inhibition of AMPA receptors contributes little to the hypnotic action of the barbiturates.

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