In the large lesion group (LS), a photothrombotic
sensorimotor cortex infarct was induced by illumination
using a 4-mm aperture fiber optic bundle, whereas
motor cortex infarct was induced in the small lesion
group (SS) using a 2-mm aperture fiber optic bundle.
The photochemical dye Rose Bengal (Sigma)
was infused by intraperitoneal (IP) injection for 5 min
(20 mg/kg), after which the light was switched on for
20 min. Sham control animals were subjected to exposure
of light without Rose Bengal IP injection for
20 min. The stereotaxic coordinates were as follows:
motor cortex anteroposterior (AP), 0 mm, mediolateral
(ML), 3 mm; sensorimotor cortex AP, 0 mm, ML,
4 mm. The rats were removed from the frame, sutured,
and allowed to recover in an incubator before being
returned to their cages. Sham control animals were not
damaged by cold light illumination.