Limits...
Patch-clamp recordings of rat neurons from acute brain slices of the somatosensory cortex during magnetic stimulation.

Pashut T, Magidov D, Ben-Porat H, Wolfus S, Friedman A, Perel E, Lavidor M, Bar-Gad I, Yeshurun Y, Korngreen A - Front Cell Neurosci (2014)

Bottom Line: Although transcranial magnetic stimulation (TMS) is a popular tool for both basic research and clinical applications, its actions on nerve cells are only partially understood.In agreement with the modeling, our recordings demonstrate the dependence of magnetic stimulation-triggered action potentials on the type and state of the neuron and its orientation within the magnetic field.Our results suggest that the observed effects of TMS are deeply rooted in the biophysical properties of single neurons in the central nervous system and provide a framework both for interpreting existing TMS data and developing new simulation-based tools and therapies.

View Article: PubMed Central - PubMed

Affiliation: The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University Ramat-Gan, Israel.

ABSTRACT
Although transcranial magnetic stimulation (TMS) is a popular tool for both basic research and clinical applications, its actions on nerve cells are only partially understood. We have previously predicted, using compartmental modeling, that magnetic stimulation of central nervous system neurons depolarized the soma followed by initiation of an action potential in the initial segment of the axon. The simulations also predict that neurons with low current threshold are more susceptible to magnetic stimulation. Here we tested these theoretical predictions by combining in vitro patch-clamp recordings from rat brain slices with magnetic stimulation and compartmental modeling. In agreement with the modeling, our recordings demonstrate the dependence of magnetic stimulation-triggered action potentials on the type and state of the neuron and its orientation within the magnetic field. Our results suggest that the observed effects of TMS are deeply rooted in the biophysical properties of single neurons in the central nervous system and provide a framework both for interpreting existing TMS data and developing new simulation-based tools and therapies.

No MeSH data available.


Related in: MedlinePlus

The electromagnetic field induced by the magnetic coil. (A) Schematic illustration of the structure of the magnetic coil. The magnetic coil was wound from copper wire of 0.75 mm diameter and constructed with two layers with 14 turns each. (B) The induced electric field of the coil was calculated with MATLAB, assuming a distance of 2 mm from the brain slice, and plotted along the x–y plane. (C) The shape and magnitude of the magnetic pulse were recorded from our coil with a pick-up coil (radius 1 cm). The signal was recorded with five different voltages applied to the capacitor bank by the high voltage power supply. The maximal magnetic field at the center of the coil is noted in color in the legend. The scale bar displays the raw voltage recorded from the pick-up coil.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4042461&req=5

Figure 2: The electromagnetic field induced by the magnetic coil. (A) Schematic illustration of the structure of the magnetic coil. The magnetic coil was wound from copper wire of 0.75 mm diameter and constructed with two layers with 14 turns each. (B) The induced electric field of the coil was calculated with MATLAB, assuming a distance of 2 mm from the brain slice, and plotted along the x–y plane. (C) The shape and magnitude of the magnetic pulse were recorded from our coil with a pick-up coil (radius 1 cm). The signal was recorded with five different voltages applied to the capacitor bank by the high voltage power supply. The maximal magnetic field at the center of the coil is noted in color in the legend. The scale bar displays the raw voltage recorded from the pick-up coil.

Mentions: To attach the patch electrode to a cortical neuron, the coil was positioned concentrically to the light path (Figure 1A). Since the induced electric field along the central axis of a round coil is zero (Figure 2B), neurons in the focal plane of the microscope are not excited when the coil is concentric to the light path. Therefore, the coil was mounted on a horizontal, plastic arm mounted on manual micromanipulator (Figure 1C). Once the patch electrode was securely connected to the neuron, the coil was moved sideways by 1 cm so that the circumference of the coil, where the induced electric field is maximal (Figure 2B), was below the neuron being recorded (Figure 1B).


Patch-clamp recordings of rat neurons from acute brain slices of the somatosensory cortex during magnetic stimulation.

Pashut T, Magidov D, Ben-Porat H, Wolfus S, Friedman A, Perel E, Lavidor M, Bar-Gad I, Yeshurun Y, Korngreen A - Front Cell Neurosci (2014)

The electromagnetic field induced by the magnetic coil. (A) Schematic illustration of the structure of the magnetic coil. The magnetic coil was wound from copper wire of 0.75 mm diameter and constructed with two layers with 14 turns each. (B) The induced electric field of the coil was calculated with MATLAB, assuming a distance of 2 mm from the brain slice, and plotted along the x–y plane. (C) The shape and magnitude of the magnetic pulse were recorded from our coil with a pick-up coil (radius 1 cm). The signal was recorded with five different voltages applied to the capacitor bank by the high voltage power supply. The maximal magnetic field at the center of the coil is noted in color in the legend. The scale bar displays the raw voltage recorded from the pick-up coil.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4042461&req=5

Figure 2: The electromagnetic field induced by the magnetic coil. (A) Schematic illustration of the structure of the magnetic coil. The magnetic coil was wound from copper wire of 0.75 mm diameter and constructed with two layers with 14 turns each. (B) The induced electric field of the coil was calculated with MATLAB, assuming a distance of 2 mm from the brain slice, and plotted along the x–y plane. (C) The shape and magnitude of the magnetic pulse were recorded from our coil with a pick-up coil (radius 1 cm). The signal was recorded with five different voltages applied to the capacitor bank by the high voltage power supply. The maximal magnetic field at the center of the coil is noted in color in the legend. The scale bar displays the raw voltage recorded from the pick-up coil.
Mentions: To attach the patch electrode to a cortical neuron, the coil was positioned concentrically to the light path (Figure 1A). Since the induced electric field along the central axis of a round coil is zero (Figure 2B), neurons in the focal plane of the microscope are not excited when the coil is concentric to the light path. Therefore, the coil was mounted on a horizontal, plastic arm mounted on manual micromanipulator (Figure 1C). Once the patch electrode was securely connected to the neuron, the coil was moved sideways by 1 cm so that the circumference of the coil, where the induced electric field is maximal (Figure 2B), was below the neuron being recorded (Figure 1B).

Bottom Line: Although transcranial magnetic stimulation (TMS) is a popular tool for both basic research and clinical applications, its actions on nerve cells are only partially understood.In agreement with the modeling, our recordings demonstrate the dependence of magnetic stimulation-triggered action potentials on the type and state of the neuron and its orientation within the magnetic field.Our results suggest that the observed effects of TMS are deeply rooted in the biophysical properties of single neurons in the central nervous system and provide a framework both for interpreting existing TMS data and developing new simulation-based tools and therapies.

View Article: PubMed Central - PubMed

Affiliation: The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University Ramat-Gan, Israel.

ABSTRACT
Although transcranial magnetic stimulation (TMS) is a popular tool for both basic research and clinical applications, its actions on nerve cells are only partially understood. We have previously predicted, using compartmental modeling, that magnetic stimulation of central nervous system neurons depolarized the soma followed by initiation of an action potential in the initial segment of the axon. The simulations also predict that neurons with low current threshold are more susceptible to magnetic stimulation. Here we tested these theoretical predictions by combining in vitro patch-clamp recordings from rat brain slices with magnetic stimulation and compartmental modeling. In agreement with the modeling, our recordings demonstrate the dependence of magnetic stimulation-triggered action potentials on the type and state of the neuron and its orientation within the magnetic field. Our results suggest that the observed effects of TMS are deeply rooted in the biophysical properties of single neurons in the central nervous system and provide a framework both for interpreting existing TMS data and developing new simulation-based tools and therapies.

No MeSH data available.


Related in: MedlinePlus