FIGURE 8.

Histological analysis of the cervical spinal cord in rats 7 and 30 days after tMCAO. (A) Cervical spinal cord sections were stained with Luxol fast blue (LFB) and Cresyl violet (cv) for analysis of myelin and motor neurons. Zones of the descending tracts are indicated on the right side and the ascending tracts on the left side of the cervical spinal cord in control rats demonstrated normal myelin staining (middle part). At 7 days post-tMCAO, areas of myelin pallor in white matter spinal cord, weakly stained by LFB, were primarily present on the left side of the spinal cord, contralateral to tMCAO insult, of the descending (ReST and RST) and the ascending (STT) tracts. Some degree of demyelination was seen in dCST at C3 level on the right side of the cervical spinal cord, ipsilateral to tMCAO. (right part) In rats after 30 days tMCAO, demyelinated areas were similarly observed in the descending (ReST and RST) and the ascending (FC and STT) tracts on the left side of the spinal cord. Also, ReST and STT were affected on the right side. Abbreviations: descending tracts: dorsal Corticospinal Tract (dCST), Reticulospinal Tract (ReST), Rubrospinal Tract (RST); ascending tracts: Fasciculus Cuneatus (FC, tract of Burdach), Spinothalamic Tract (STT), ventral horn (VH). Mark hole on coronal spinal cord sections indicates the right side. Magnification: coronal spinal cord section is 4×, inserts on both sides of coronal sections are 20×. (B) Stereological motor neuron counts on both the right and left sides of discrete levels of the cervical spinal cord demonstrated substantial cell loss in rats at 7 and 30 days after tMCAO versus controls. Motor neuron numbers were significantly (p < 0.001) decreased on the left side of the spinal cord primarily at C5-C6 and C7-C8 levels in animals at subacute (7 days) and chronic (30 days) tMCAO stages. C2-C3, C5-C6, and C7-C8 are levels of the cervical spinal cord. *p < 0.05; **p < 0.01; ***p < 0.001.