Bioelectromagnetic Platform for Cell, Tissue, and In Vivo Stimulation

Abstract

Magnetogenetics is a new field that utilizes electromagnetic fields to remotely control cellular activity. In addition to the development of the biological genetic tools, this approach requires designing hardware with a specific set of demands for the electromagnets used to provide the desired stimulation for electrophysiology and imaging experiments. Here, we present a universal stimulus delivery system comprising four magnet designs compatible with electrophysiology, fluorescence and luminescence imaging, microscopy, and freely behaving animal experiments. The overall system includes a low-cost stimulation controller that enables rapid switching between active and sham stimulation trials as well as precise control of stimulation delivery thereby enabling repeatable and reproducible measurements.

Proposed three-phenylalanine motif involved in magnetoreception signaling of an Actinopterygii protein expressed in mammalian cells

“…3); HeLa cells were grown in 35 mm tissue culture dishes and stimulated with a custom electromagnetic air-core coil that fits a 35 mm dish in its center. 19 The coil utilizes double wrapped copper wires that allow for both active and sham stimuli to be produced. The active stimulus is produced when current is run in the same direction in both wires.…”

“…The sham stimulus is produced when current is run in opposite directions; this anti-parallel configuration cancels the formation of a magnetic field. 19 The sham is an ideal control in this case because the sample is still subjected to the heat and electricity associated with the magnet, without the magnetic field. 5,20 Cells were stimulated using a pulse pattern and fluorescence of GCaMP6m was observed for the duration of the experiment using a GFP filter to yield a video such as Video S1.…”

“…This period lasts about 1 second at the beginning and 1 second at the end of each of the 4 pulses. 19…”

Magnetogenetic closed-loop reduction of seizure activity in a rat model of epilepsy

“…Here we tested if the magnetic elds induced during a seizure in the established kainic acid (KA) rat model 27 could be used both as the sensor and the activator to suppress seizure activity in an animal model. We capitalized on a recently discovered membraneassociated protein that is sensitive to magnetic elds, the Electromagnetic Perceptive Gene (EPG) [28][29][30][31] ; it was demonstrated that remote activation of EPG by electromagnetic elds signi cantly increases intracellular calcium concentrations, indicative of cellular excitability 32 . Thus, we tested if EPG expressed in inhibitory hippocampal interneurons will be sensitive to the magnetic elds generated during a seizure, that in turn will activate the inhibitory interneurons which will shut down or disrupt the circuit, interrupting seizure activity and progression in a closed-loop and cell-speci c fashion.…”

Magnetogenetic closed-loop reduction of seizure activity in a rat model of epilepsy

“…Here we tested if the magnetic fields induced during a seizure in the established kainic acid (KA) rat model 27 could be used both as the sensor and the activator to suppress seizure activity in an animal model. We capitalized on a recently discovered membrane-associated protein that is sensitive to magnetic fields, the Electromagnetic Perceptive Gene (EPG) [28][29][30][31] ; it was demonstrated that remote activation of EPG by electromagnetic fields significantly increases intracellular calcium concentrations, indicative of cellular excitability 32 . Thus, we tested if EPG expressed in inhibitory hippocampal interneurons will be sensitive to the magnetic fields generated during a seizure, that in turn will activate the inhibitory interneurons which will shut down or disrupt the circuit, interrupting seizure activity and progression in a closed-loop and cell-specific fashion.…”