Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision Both sides next revision
tutorial:mouse_eeg [2018/10/21 15:01]
42.49.180.224 [Mouse EEG - channel and source analysis]
tutorial:mouse_eeg [2017/08/17 11:21] (current)
127.0.0.1 external edit
Line 56: Line 56:
  
 Sensorymotor integration is a neurological process dealing with somatosensation inputs into motor outputs in an effective way. Numerous studies have shown the direct signal pathways within somatosensor-motor circuits, however little is known how the tactile sensations with different stimulation frequency are processed from somatosensory to motor cortex in order to react appropriately to different types of stimulation. In present study, we mimicked the peripheral sensation by direct stimulation of S1, S2, M1 and sensory thalamus using optogenetic method and concurrently recorded the frequency dependent responses (1, 10, 20, 30, 40 and 50 Hz) with a depth electrode in the region of the optode (i.e. S1, S2, M1 and thalamus), and recording the EEG using the surface micro electrode array. Sensorymotor integration is a neurological process dealing with somatosensation inputs into motor outputs in an effective way. Numerous studies have shown the direct signal pathways within somatosensor-motor circuits, however little is known how the tactile sensations with different stimulation frequency are processed from somatosensory to motor cortex in order to react appropriately to different types of stimulation. In present study, we mimicked the peripheral sensation by direct stimulation of S1, S2, M1 and sensory thalamus using optogenetic method and concurrently recorded the frequency dependent responses (1, 10, 20, 30, 40 and 50 Hz) with a depth electrode in the region of the optode (i.e. S1, S2, M1 and thalamus), and recording the EEG using the surface micro electrode array.
-====== Mouse EEG - channel ​and source analysis ​ ======+==== Subject ​and Experiment ​==== 
 +In the study applied here, we used the transgenic mice (Thy1-ChR2-EYFP,​ B6 mice, 12 weeks; body weight 27 g, male[[http://​jaxmice.jax.org/​strain/​007615.html]]). For implantation of electrodes on the skull and sensory thalamus (VPM; 1.82 mm posterior, 1.5 mm lateral and 3.7 mm ventral to bregma), mice were anesthetized (ketamine/​xylazine cocktail, 120 and 6 mg/kg, respectively) and then positioned in a stereotaxic apparatus. Location of electrode placement is going to describe in section ?. We allocated two electrodes in the most anterior region as reference and ground electrodes. The brain signals are recorded by both high-density electrode array (EEG-38 channels + ground and reference-2 channels) and local field potential (single channel). The EEGs were acquired with an analog amplifier (Synamp, Neuroscan, USA) with a sampling frequency of 2000 Hz.  
 ==== Optogenetic Stimulation ==== ==== Optogenetic Stimulation ====
 For optogenetic stimulation,​ we used a semiconductor laser (USA & BCL-040-445;​ 445 nm wavelength and 40 mW/mm2 maximum output power; CrystaLaser LLC., Reno, NV, USA) that was gated using a pulse generator (575 digital delay, Berkeley Nucleonics Corp., Berkeley, CA, USA). Blue light from the laser was guided to the brain using an optic fiber with clad/core diameters of 125 mm and 3.4 mm, respectively (P1-405A-FC-5;​ Thorlabs Inc., Newton, NJ, USA). The light intensity from the tip of optical fiber was approximately 2 mW/mm2 measured by integrating sphere coupled to spectrometer (BLUE-Wave-VIS2/​IC2/​IRRAD-CAL,​ Stellar-Net Inc., Tampa, FL, USA). Various pulse trains with a 20 ms pulse width were delivered in four different cortical regions (somatosensory cortices, primary motor cortex, and sensory thalamus marked as S1, S2, M1, and VPM in below figure, respectively). For optogenetic stimulation,​ we used a semiconductor laser (USA & BCL-040-445;​ 445 nm wavelength and 40 mW/mm2 maximum output power; CrystaLaser LLC., Reno, NV, USA) that was gated using a pulse generator (575 digital delay, Berkeley Nucleonics Corp., Berkeley, CA, USA). Blue light from the laser was guided to the brain using an optic fiber with clad/core diameters of 125 mm and 3.4 mm, respectively (P1-405A-FC-5;​ Thorlabs Inc., Newton, NJ, USA). The light intensity from the tip of optical fiber was approximately 2 mW/mm2 measured by integrating sphere coupled to spectrometer (BLUE-Wave-VIS2/​IC2/​IRRAD-CAL,​ Stellar-Net Inc., Tampa, FL, USA). Various pulse trains with a 20 ms pulse width were delivered in four different cortical regions (somatosensory cortices, primary motor cortex, and sensory thalamus marked as S1, S2, M1, and VPM in below figure, respectively).