Table 1.
Summary of the glial-cell ablation studies’ methodology and main results.
| Ablated Cell Type | Cell Ablation Technique | Species/ Strain |
Animal Age | Time-Point of Cell Ablation | Time-Point of Tissue Collection | Consequences of Cell Ablation | Reference |
|---|---|---|---|---|---|---|---|
| Astrocytes | GFAP-Tk mice. Tk-GCV system | Transgenic mice on C57BL/6J background | Not specified | from 0 to 7 dpi | 14 dpi | Tissue degeneration. Increased infiltration of pro-inflammatory cells. Failed repair of the BBB. Reduced oligodendrocyte and neuronal survival. Increased demyelination. Impaired locomotor recovery. | [29] |
| Astrocytes | GFAP-Tk mice. Tk-GCV system | Transgenic mice on C57BL/6J background (females) | 8–16 weeks | from 0 to 7 dpi | 14–56 dpi | Lesion expansion. Unchanged axonal regrowth and extended axonal dieback. Maintained CSPGs production. Ablation of astrocytes eliminates the beneficial effect of conditioning lesions and neurotrophic factors on axonal regrowth. | [21] |
| loxP-DTR mice. DTA-DTR system | loxP-DTR mice on C57BL/6 background (females) | 8–16 weeks | from 35 to 45 dpi | 70 dpi | Tissue degeneration and lesion expansion. Axon regrowth was not enhanced. | ||
| Astrocytes | lentivirus-mediated Tk/GCV system | C57BL/6 mice (females) | 8–12 weeks | from 1 to 8 dpi | 14, 28, and 42 dpi | Enhanced infiltration of proinflammatory cells and tissue damage. Augmented neuronal death. Impaired locomotor recovery | [30] |
| Microglia | PLX5622 Feeding | C57BL/6N mice | 8–10 weeks | from 21 d before injury to 35 dpi; from 0 to 35 dpi; from 21 d before injury to 0 dpi | 1, 4, 7, 14 and 35 dpi | Disorganization of the glial scar. Enhanced infiltration of immune cells. Reduced oligodendrocyte and neuronal survival. Impaired locomotor recovery | [31] |
| Microglia | PLX3397 Intragastric | C57BL/6 mice (females) | 8–10 weeks | 14 days pre-injury until 7 or 14 dpi | 7 and 14 dpi | Disorganization of the glial scar. Reduced astrocytic proliferation. Increased proinflammatory factors. Reduced neuronal survival. Impaired locomotor recovery. | [32] |
| Microglia | PLX3397 Feeding | C57BL/6 mice (females) | 6 weeks | from 7 days before injury to 28 dpi | 7, 14, 28, 30, and 56 dpi | Disorganization of the glial scar. Acute expansion of the lesion. Increased axon dieback. Impaired locomotor recovery | [33] |
| NG2 cells | NG2-Tk mice. Tk-GCV system | Transgenic mice on C57BL/6J background | 12 weeks | from 0 dpi to 7 or 14 dpi | 7, 14, and 21 dpi | Edema and swelling. Reduced intra-lesion laminin. Disorganization of astrocytes and the glial scar. Increased macrophage infiltration. Enhanced axon regrowth. Impaired locomotor recovery. | [34] |
Tk-GCV—thymidine kinase-ganciclovir; dpi—days post-injury; DTA-DTR—diphtheria toxin subunit A-diphtheria tox.