MRI Compatible, Customizable, and 3D-Printable Microdrive for Neuroscience Research

Area of Science:

• Neuroscience
• Biomedical Engineering
• Medical Imaging

Background:

• Assessing brain network effective connectivity requires quantifying electrical microstimulation (EM) effects on neuronal activity using functional magnetic resonance imaging (fMRI).
• Precise EM delivery, especially layer-specific, necessitates MRI-compatible equipment for controlled electrode placement and artifact reduction.

Purpose of the Study:

• To develop and validate an MRI-compatible microdrive for precise EM delivery during fMRI.
• To enable detailed investigation of brain network dynamics and connectivity.

Main Methods:

• Developed a microdrive using MRI-compatible materials with an integrated penetration grid and microdrilling technique.
• Utilized a screw-type actuator for multi-electrode insertion/repositioning and a built-in MRI marker for trajectory estimation.
• Conducted an EM-coupled fMRI study in a macaque monkey at 7 Tesla (7T).

Main Results:

• The microdrive successfully delivered EM during MRI with minimal imaging artifacts in a 7T environment.
• Validated the microdrive's compatibility and efficacy for precise electrode placement and stimulation.
• Demonstrated the utility of the integrated penetration grid as an MRI fiducial marker.

Conclusions:

• The developed microdrive offers a cost-effective, convenient solution for MRI-compatible neuromodulation research.
• Facilitates future applications in neuronal recording and targeted drug delivery.
• Provides open-access CAD templates and parts lists for broader neuroscience research adoption.