High-density EEG Recordings of the Freely Moving Mice using Polyimide-based Microelectrode

Hi, I'm Mina Lee from Gen Choice Laboratory in the Center for Neuroscience at the Korea Institute of Science and Technology. Today we will demonstrate the condition of high density EG in the mass model with poly based micro electrode array. The procedure involves setting up the instruments, preparing animals for surgery, and performing stereo toxic surgery.

After the surgery, we'll perform EEG recording and then analyze data. Let's get started. Before starting the surgery, set up the stereo toxic instruments and all the materials needed.

The environment should be clean. Prepare the mouse for surgery. I will demonstrate today's surgery using a 17 weeks old basic six black six J 1 29 s four S-V-J-A-E hybrid mouse.

We can also use mice that are heavier than 25 grams. Anize the mouse with an IP injection of cocktail containing 120 milligram per kilogram, ketamine and six milligram per kilogram outlet. Gently pinch the mouse tail or to, to make sure that the mouse is anesthetized deeply enough to proceed with the surgery.

To begin the surgery, mount the animal onto the stereo toxic apart. Place the air barss into the mouse connel one by one and make it tight. Put some methanol on his head and then shape the far of his head.

Inject, make anterior posterior incision from between the eyes to between the ears and the skull. Pinch the skin in the mouse using micro clamps in order to keep the incision wide up. Remove any remaining tissue or membrane from the skull with the sterilized cut swaps.

Put the marking pen above its head. Mark the BMA lambda points. Then remove the marking pen and mark the points using an old best pen.

Right on the mark. The point. Bring the film electrode above the head and put a drop of T water on the skull.

Place the BMA on the middle of the fifth layer of the Ontario of the poly best micro electro array. Sub the film carefully from the medial to later with the water soft cotton swaps. Give a few minutes until it dries completely.

This helps with better adherence. Make three pen marks with an oil-based pen at the residual space. These marks are where you'll be drilling.

Be very careful with drilling the holes not to touch the inside. Place the three steril lines steering screws onto the skull and place them in until they are tightly in cordon. Mix a thick batch of liquid, liquid, accurately dental cement and cover the film electrode screws and the rest of the skull.

Make another batch and use it to completely cover the electrode. Uncover the screws again to secure it. Remember, this man should not be under the film electrode.

Put double signe that has tape on the back of the connector plane. Place a rigid stick as a strap on the middle of the skull using strong glue. In today's experiment, I use a tip of a cutting swab for this stick step, manipulate the connector position to be backwards until it makes contact with the tip of the cutting spot.

Distance between the skull and the connector should be more than five millimeters. Stick the connector plane on the tip of the cotton swap by adding strong glue. Cover the rest of open area with acrylic ul cement.

After the cement curing, remove the clamps and stir the skin. Remove the mouse from the parus and cover the extra space. With acrylic dental cement apply antibiotic sodium ate around the cement and the suture area.

Place the mouse in its own cage and give a list of five days for recovery. Connect the mouse to the EEG and pull fire and give more than one hour for habitation. After an hour perform EEG recording, we performed the acquisition of high density EEG in a mouse model with a poly based micro electrode array.

When doing this procedure, it is important to remember to handle the film electro Tri gently because it is only seven micrometers thick. A, a drop of tap water is necessary when you rearrange the electrode. If you skip this step, the electrode can be turned easily and make sure acrylic dentals made with high viscosity does not permeate under the film.

After recording, we conduct offline analysis using meth lab to draw several brain graphs for clearly visualizing the brain activities in mice. This is the representative multichannel EEG signals after GBL injection. On the left panel, you can see the representative multichannel e signals after GBL injection on the right panel.

Brain topography maps such as average power time delay, average peak strength and average probability map of seizure onset are presented. So that's it. Thanks for watching.