Electroencephalographic Recording of Epileptic Seizures in Epilepsy-Induced Rats

Take an epilepsy-induced rat with an electrode implanted in the skull. The tip of the electrode is inserted into the ventral hippocampus region.

Connect an electroencephalography, or EEG, recording system to the implanted electrode.

Transfer the rat to a plexiglass cylinder to record brain activity while the animal moves freely.

Epilepsy induction results in an increased release of excitatory neurotransmitters in the synapse of neurons while the release of inhibitory neurotransmitters decreases, disrupting the equilibrium between excitatory and inhibitory signals.

The increased excitatory neurotransmitters trigger a continuous influx of positive ions, making the neurons hyperexcitable. This causes a continuous generation of electrical signals.

A burst of synchronous electrical activity by neighboring neurons at a high frequency is termed an epileptic seizure.

Using the implanted electrode, record the abnormal burst of brain activity to identify the occurrence of seizures in the epilepsy-induced rat.

Begin by switching on the amplifier positioned outside of the Faraday cage. Open the EEG software, and start the EEG acquisition, and observe the EEG signal produced by unconnected cables.

Next, connect the animal to the tethered EEG recording system by holding the animal's head between two stretched fingers of one hand, and screwing down the connectors to the electrode pedestal using the other free hand.

Set an amplification factor on each channel of the amplifier according to the electrode signal of a single animal so the EEG signal is in scale. Then, let the animal explore the new cage for at least one hour under the direct observation of the researcher.

Adjust the cable according to the animal's commodity, and ensure that the cables do not interfere with the animal's movements and lying posture.