Three weeks after BDA injection (4 weeks after
stroke), the animals were anesthetized with ketamine
and perfused transcardially with saline, followed by
4% paraformaldehyde. The entire brain was removed
and immersed in 4% paraformaldehyde overnight.
The brain tissues were processed to produce adjacent
40-m-thick coronal sections using a cryostat. Five
sections including the red nucleus (RN) and cerebral
peduncle (CP) (–4.52 to –6.04 mm at AP) and five sections
including the pyramid (Py) (–8.72 to –11.60 mm
at AP) were used to detect BDA labeling. Briefly, free-
floating sections were incubated with 0.3% H2O2 in
0.1 M phosphate-buffered saline (PBS, pH 7.4) for
20 min, washed with 0.1 M PBS, then incubated in
0.1 M PBS containing 5% normal horse serum and
0.3% Triton X-100 for 1 h. The sections were incubated
with avidin–biotin–peroxidase complex (Vector Laboratories,
Burlingame, CA, USA) in PBS/Triton X-100
at 4°C for 3 days and BDA labeling was achieved with
0.05% 3,3
-diaminobenzidine and 0.003% H2O2 (Vector
Laboratories) before light microscopy examination.