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Updated: May 3, 2026
Photothrombotic Ischemia: A Minimally Invasive and Reproducible Photochemical Cortical Lesion Model for Mouse Stroke Studies
Published on: June 9, 2013
A step-by-step approach to minimally photothrombotic ischemic stroke in the hippocampal region that simulates human
Farzaneh Fazli1, Hamid Tayefi Nasrabadi1, Reza Rahbarghazi1
1Tabriz University of Medical Sciences, Tabriz, Iran, Islamic Republic of.
Abstract:
The hippocampal structure, characterized by blood vessels with an average diameter of 0.5 mm, exhibits a significant vulnerability to ischemic conditions and is the critical region in the learning process and memory establishment. Male mice (n = 30) were divided into three groups (each group n = 10). 1) Rose Bengal group, 2) Laser group, 3) Rose Bengal + Laser group. Mice were placed in a stereotaxic device. An optical fiber was positioned above the ascending part of the hippocampal fissure and illuminated for 15 min using a previously injected intraperitoneal Rose Bengal dye. The Passive avoidance and MWM tests evaluated learning ability and memory capacity. TTC and Cresyl violet staining were conducted to assess the neural tissue morphology and histological alterations. Photochemical stroke resulted in hemorrhagic tissue and pale ischemic changes over three days. Microscopic analysis revealed neural tissue degeneration and disruption in the (Rose Bengal + Laser) group compared to the other experimental groups. The passive avoidance test demonstrated a statistically significant reduction in the time required to reach the dark compartment within the (Rose Bengal + Laser) group relative to the other groups (P < 0.001). Furthermore, treatment with Rose Bengal and laser irradiation was associated with a decline in spatial learning and memory, as evidenced by decreased time spent in the target quadrant compared to the other quadrants (P < 0.001). Our findings indicate that the application of Rose Bengal alongside laser irradiation results in cellular injury, disruption of neural tissue, and impairment of learning and memory performance.
Insights
Photochemical stroke using Rose Bengal dye and laser irradiation significantly impairs learning and memory in mice. This method causes neural tissue damage, highlighting its detrimental effects on cognitive functions.
Area of Science:
- Neuroscience
- Biomedical Engineering
- Cellular Biology
Background:
- The hippocampus is crucial for learning and memory.
- Hippocampal vulnerability to ischemia poses a significant research challenge.
- Understanding mechanisms of neural injury is vital for cognitive health.
Purpose of the Study:
- To investigate the effects of Rose Bengal and laser irradiation on hippocampal function.
- To assess the impact of photochemical stroke on learning and memory in mice.
- To evaluate histological changes associated with this experimental stroke model.
Main Methods:
- Male mice (n=30) were divided into three groups: Rose Bengal, Laser, and Rose Bengal + Laser.
- Photochemical stroke was induced using Rose Bengal dye and laser illumination.
- Learning and memory were assessed using Passive Avoidance and Morris Water Maze (MWM) tests.
- Histological analysis included TTC and Cresyl violet staining for neural tissue evaluation.
Main Results:
- The Rose Bengal + Laser group exhibited hemorrhagic tissue and ischemic changes.
- Microscopic analysis revealed significant neural tissue degeneration and disruption in the combined treatment group.
- Impaired learning and memory performance were observed in the Rose Bengal + Laser group, with reduced avoidance times and decreased time in the target quadrant (P < 0.001).
Conclusions:
- Combined Rose Bengal and laser irradiation induces cellular injury and neural tissue disruption.
- This experimental model effectively impairs learning and memory functions.
- Findings highlight the detrimental impact of photochemical stroke on cognitive performance.
