Basic NeuroscienceA MRI-compatible system for whisker stimulation

We describe here a system for whisker stimulation designed for functional studies in high-field magnetic resonance imaging (MRI) environments. This system, which incorporates real-time optical monitoring of the vibration stimulus, can generate well-controlled and reproducible whisker deflections with amplitudes up to 2 mm and frequencies up to 75 Hz, suitable for functional magnetic resonance imaging (fMRI) studies of animals. Whiskers on either or both sides of the head can be stimulated selectively during fMRI experiments without removing the subject from the magnet. With a user-friendly graphical interface of a computer, a user can conveniently control both the whisker vibration and gating of the MR imager, and synchronize the stimulation with the fMRI acquisition to ensure precise timing of the stimulus presentation. This whisker stimulation system should facilitate a wide variety of fMRI investigations of the neural systems mediating sensory information from the whiskers.

► We designed, constructed and tested a whisker stimulator for high-field MRI systems. ► Mechanical vibration of a coil of wire is coupled to whiskers. ► The whisker deflection is monitored in real time with an optical system. ► The stimulator deflects whiskers at frequencies up to 75 Hz and amplitudes up to 2 mm. ► The whisker deflection can be synchronized with fMRI data acquisitions.