Name: simultaneous fmri and electrophysiology in the rodent brain
Uploaded: 2010-08-19T17:00:00
Description: Watch this Scientific Journal Video about Simultaneous fMRI and Electrophysiology in the Rodent Brain at JoVE.com

The work was supported by NIH 1 R21NS057718-01.

1. This is a non-survival surgery. The first step is implantation of the electrodes. In this example, electrodes will be implanted in the forepaw regions of primary somatosensory cortex of both hemispheres.
<ol>
	<li>Anesthetize the rat (male SD rat, 200-300 g) with 2% isoflurane and fix into place on a stereotactic surgical system. Before beginning surgery, ensure that the animal is well anesthetized and exhibits no response to a toe pinch. Remove the fur before opening the scalp. Separate the muscle and other tis...

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Both electrophysiological recording and BOLD fMRI are separately well-developed techniques. However, simultaneously recording and imaging is challenging due to the mutual interference2 of the two modalities. Here we provide a possible solution for combined experiments in the rodent. The modified method of electrode implantation minimizes influence on the image quality, and the artifact removal for the electrical recordings is necessary to remove the noise induced by image acquisition. Simultaneous imaging and ...

simultaneous fmri and electrophysiology in the rodent brain

To examine the neural basis of the blood oxygenation level dependent (BOLD) magnetic resonance imaging (MRI) signal, we have developed a rodent model in which functional MRI data and in vivo intracortical recording can be performed simultaneously. The combination of MRI and electrical recording is technically challenging because the electrodes used for recording distort the MRI images and the MRI acquisition induces noise in the electrical recording. To minimize the mutual interference of the two modalities, glass microelectrodes were used rather than metal and a noise removal algorithm was implemented for the electrophysiology data. In our studies, two microelectrodes were separately implanted in bilateral primary somatosensory cortices (SI) of the rat and fixed in place. One coronal slice covering the electrode tips was selected for functional MRI. Electrode shafts and fixation positions were not included in the image slice to avoid imaging artifacts. The removed scalp was replaced with toothpaste to reduce susceptibility mismatch and prevent Gibbs ringing artifacts in the images. The artifact structure induced in the electrical recordings by the rapidly-switching magnetic fields during image acquisition was characterized by averaging all cycles of scans for each run. The noise structure during imaging was then subtracted from original recordings. The denoised time courses were then used for further analysis in combination with the fMRI data. As an example, the simultaneous acquisition was used to determine the relationship between spontaneous fMRI BOLD signals and band-limited intracortical electrical activity. Simultaneous fMRI and electrophysiological recording in the rodent will provide a platform for many exciting applications in neuroscience in addition to elucidating the relationship between the fMRI BOLD signal and neuronal activity.

Watch this Scientific Journal Video about Simultaneous fMRI and Electrophysiology in the Rodent Brain at JoVE.com

Simultaneous fMRI and Electrophysiology in the Rodent Brain

We have developed a method for simultaneous functional magnetic resonance imaging and electrophysiological recording in the rodent brain, providing a platform for the investigation of the relationship between neural activity and the blood oxygenation level dependent (BOLD) MRI signal.

To examine the neural basis of the blood oxygenation level dependent (BOLD) magnetic resonance imaging (MRI) signal, we have developed a rodent model in ...

Research

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