Figure 1.
Processes of an oligodendrocyte gradually regenerate after severing.
The processes of an untreated oligodendrocyte (A) were severed using a scalpel. After cutting, the processes gradually regenerated in 36 h (B). The processes of a second untreated oligodendrocyte (C) were also cut in the same way, and likewise regenerated in 36 h (D). The 36-h image of cell No. 2 viewed by immunofluorescence microscopy: MBP, green; DAPI, blue (E). Images of two additional oligodendrocytes (No. 3, No. 4) after their processes were severed are shown (F). The severed processes of No. 3 and No. 4 re-extended in 24 and 16 h, respectively. The severing tracks are dotted (B, D, F). ‘No.’ is an arbitrary reference number for individual oligodendrocytes.
Figure 2.
NMDA stimulation causes reversible retraction of oligodendrocyte processes.
An untreated oligodendrocyte was stimulated with NMDA, which gradually caused retraction of the processes over 36 h, but the soma appeared intact. The leading edges of representative processes are marked by dots (A). The processes were progressively regenerated within 8 h after the removal of NMDA from the culture medium (B). The 8-h image of cell No. 1 viewed by immunofluorescence microscopy: MBP, green; DAPI, blue (C). Images of other representative cells (No. 2, No. 3), with NMDA and after its removal (D). Statistical analysis indicates that moderate NMDA treatment for 36 h significantly retract oligodendrocyte processes, which recovered 8 h after the removal of NMDA (E) (n = 5, each; ** p<0.01). ‘No.’ is an arbitrary reference number for individual oligodendrocytes.