previously described.28 (link) Briefly, four rats from each group were selected, deeply anesthetized,
and exsanguinated. Then, the lumbar enlargements were removed, soaked in 4%
phosphate-buffered paraformaldehyde for 4 to 6 h at 4 °C, and subsequently
dehydrated in a 10% to 30% gradient of sucrose in sterile water for five to
seven days at 4 °C. Next, the lumbar enlargement of the spinal cord tissues was
frozen in optimal cutting temperature (OCT) compound (Sakura, America) in a
cryostat at −25°C and then sliced at a thickness of 20 µm. The sections were
first blocked with 4% normal donkey serum, 0.03% Triton X-100, and PBS for 1 h
at room temperature. The sections were then incubated overnight at 4 °C with the
following primary antibodies: p-eIF2α (1:200, rabbit; Affinity), cleaved
caspase-3 (1:150, rabbit, Affinity), glial fibrillary acidic protein (1:1000,
mouse; Sigma), IBA-1 (1:250, mouse; Abcam), and NeuN (Mouse,1:1000, Abcam). The
sections were washed with PBST and incubated for 2 h with fluorescein
isothiocyanate- or Cy3-conjugated secondary antibodies (1:500, Abcam) at room
temperature. Finally, the stained sections were surveyed with an Olympus
fluorescence microscope, and images were acquired with a CCD Spot camera.
Finally, the images were analyzed using Image Pro-Plus 6.0 (Image Pro-Plus
Kodak, USA).