Whole-brain mapping of effective connectivity by fMRI with cortex-wide patterned optogenetics

Area of Science:

• Neuroscience
• Biomedical Engineering
• Imaging Technology

Background:

• Functional magnetic resonance imaging (fMRI) is crucial for mapping brain networks.
• Optogenetic neural manipulation offers precise control over neural activity.
• Integrating these techniques presents opportunities for advanced brain research.

Purpose of the Study:

• To develop a method for spatiotemporal optogenetic manipulation within an MRI scanner.
• To enable brain-wide effective functional network mapping in mice.
• To investigate the influence of anesthetics on brain connectivity.

Main Methods:

• Incorporation of a digital micromirror device for programmable optogenetic stimuli delivery via optical fiber bundles into an MRI scanner.
• Simultaneous in situ optical imaging and cell-type/circuit-specific genetic targeting.
• Brain-wide effective connectivity mapping using fMRI with optogenetic stimulation of atlas-based cortical regions.

Main Results:

• The developed system provides spatiotemporal flexibility in photostimulation patterns.
• Brain-wide effective connectivity maps obtained via fMRI and optogenetics align with axonal tracing data.
• Anesthetic type was found to selectively influence specific neural connections.

Conclusions:

• fMRI combined with flexible optogenetics offers a powerful new tool for high-throughput brain-wide effective connectivity mapping.
• This approach facilitates the investigation of dynamic changes in functional brain states within individual animals.
• The technique allows for detailed analysis of neural circuit function and anesthetic effects.