Simultaneous Photothrombosis and Fiber Photometry to Induce and Monitor Ischemic Stroke in Behaving Mice

Area of Science:

• Neuroscience
• Biomedical Engineering
• Stroke Research

Background:

• Stroke is a major global cause of death and disability.
• Ischemic stroke involves cerebral blood vessel obstruction, leading to neuronal damage and calcium influx.
• Anesthesia can affect stroke pathology and recovery, complicating research.

Purpose of the Study:

• To develop an all-optical method for inducing focal cerebral ischemia in awake, freely behaving mice.
• To simultaneously monitor neuronal calcium dynamics in the emerging stroke core.
• To provide a flexible and scalable model for studying acute stroke without anesthesia.

Main Methods:

• Stereotaxic fiberoptic cannula implantation in mice.
• Focal ischemia induction using Rose Bengal photothrombosis via a single optical fiber.
• Monitoring neuronal Ca2+ dynamics using GCaMP photometry in Thy1-GCaMP6f mice.
• Simultaneous behavioral assessment.

Main Results:

• Successful induction of focal ischemia in specific brain regions of awake mice.
• Real-time monitoring of neuronal Ca2+ influx in the developing stroke core.
• Demonstration of a flexible and scalable stroke model amenable to various brain regions and biosensors.

Conclusions:

• The combined photothrombosis and fiber photometry method offers a precise, region-specific approach to study acute stroke in behaving animals.
• This anesthesia-free model allows for a more accurate investigation of stroke-induced symptomology.
• The technique is adaptable for studying various neurological conditions involving neuronal activity.