Simultaneous recording of brain activity and functional connectivity in the mouse brain.

Combining of two measurement system of different scale in the mouse brain has been challenging issue due to the small size of the mouse brain. We present a novel approach to record brain activity and connectivity simultaneously by using intracranial electrode and flexible multichannel film electrode. 40 channel ultra-thin nanofabricated microelectrode covering the mouse skull was applied in this study. The null space in the microarray was cut off so that the secondary sensor or stimulator can approach to the brain. Hereby, we performed a simultaneous recording of local field potential and multichannel EEG recording in a freely moving mouse under pharmacologically driven absence seizure. A brain activity in the thalamus was depicted together with cortical EEG map. The connectivity levels between different cortical sites or between thalamus and cortical site were measured during seizure. The time lag map of cortical EEG with respect to the thalamus represents the propagation delay of the seizure.