The integrity of the structural cerebral cortex is disrupted after
stroke either at the macroscopic or microscopic levels. Therefore, many attempts have been gathered to circumvent
stroke-associated problems in the brain tissue. The current study was aimed to design an animal model of photochemical
stroke using
rose bengal (RB) plus
laser irradiation (L) after 10, 15, and 20 min (´) and evaluate its effect on the cerebral tissue using unbiased stereological quantitative methods and morphometric histological analysis. Photochemical
stroke was induced by
intraperitoneal injection of RB
dye and further activation through the exposure of the right sensorimotor cortex with the green
laser radiation (100 mW; 532 nm). Mice were randomly allocated into 4 groups (each in 15) as follows: control (10 μg/gbw RB), RB + 10'L, RB + 15'L, and RB + 20'L. Target irradiation site was adjusted to 2 mm lateral to the bregma. Vernier caliper morphometric evaluation,
cresyl violet staining, and unbiased stereological assays including Cavalier's principle and point counting techniques were used to monitor the pathological changes and lesion volume on days 1, 3, and 7 after the
ischemia induction. Our data showed that the mean diameter of the lesion site and lesion
infarct volume in the group RB + 20'L) was significantly increased relative to the other groups (P < 0.05). Notably, the lesion volume and diameter in the group RB + 15'L was larger compared with the group RB + 10'L and control mice (P < 0.05). Data showed an increased acute inflammatory response such as
hyperemia and
edema 3 days after ischemic induction while the intensity of acute changes and lesion volume were reduced and replaced with necrotic and chronic pathological changes including
astrogliosis on day 7. It is concluded that the
laser irradiation of RB-injected mice at a distinct time period could induce the magnificent degenerative effects on the cerebral cortex which is similar to the
stroke condition.