Termination of lesion-induced plasticity in the mouse barrel cortex in the absence of oligodendrocytes.
Termination of developmental plasticity occurs at specific points in development, and the mechanisms responsible for it are not well understood. One hypothesis that has been proposed is that oligodendrocytes (OLs) play an important role. Consistent with this, we found that OLs appeared in the mouse somatosensory cortex at the end of the critical period for whisker lesion-induced barrel structural plasticity. To test this hypothesis, we used two mouse lines with defective OL differentiation: Olig1-deficient and jimpy. In Olig1-deficient mice, although OLs were totally absent, the termination of lesion-induced plasticity was not delayed. The timing was normal even when the cytoarchitectonic barrel formation was temporarily blocked by pharmacological treatment in Olig1-deficient mice. Furthermore, the termination was not delayed in jimpy mice. These results demonstrate that, even though OLs appear at the end of the critical period, OLs are not intrinsically necessary for the termination of lesion-induced plasticity. Our findings underscore a mechanistic distinction between the termination of thalamocortical axonal plasticity in the barrel cortex and that in the visual cortex, in which OL-derived Nogo-A/B was recently suggested to be essential.
Toda
Tomohisa
T
Department of Molecular and Systems Neurobiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan.
Hayakawa
Itaru
I
Matsubayashi
Yutaka
Y
Tanaka
Kenji
K
Ikenaka
Kazuhiro
K
Lu
Qing Richard
QR
Kawasaki
Hiroshi
H
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D003010:Clorgyline / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008816:Mice, Jimpy; D018345:Mice, Knockout; D008996:Monoamine Oxidase Inhibitors / Q000378:metabolism; D009473:Neuronal Plasticity / Q000502:physiology*; D009836:Oligodendroglia / Q000166:cytology / Q000378:metabolism*; D013003:Somatosensory Cortex / Q000166:cytology / Q000473:pathology / Q000502:physiology; D014738:Vibrissae / Q000473:pathology*
D051792:Basic Helix-Loop-Helix Proteins; D003010:Clorgyline; D008996:Monoamine Oxidase Inhibitors; C494786:Olig1 protein, mouse