Cellular-Scale Microelectrode Arrays to Monitor Movement-Related Neuron Activities in the Epileptic Hippocampus of Awake Mice.

Abstract

Epilepsy affects 50 million people worldwide and its pathogenesis is still unknown. In particular, the movement-related neural activities involving glutamate (Glu) and electrophysiological signals at cellular level remains unclear. A cellular-scale implantable microelectrode array (MEA) was fabricated to detect the movement-related neural activities involving Glu concentration and electrophysiological signals. Platinum and reduced graphene oxide nanocomposites were deposited to enhance the surface area. Glu oxidase (Gluox) were coated to effectively recognize Glu molecule. Neural activities in the hippocampus of normal and epileptic mice is different, and the changes are closely connected with movement. Glu concentration and spike firing rate in the epileptic mice were much higher than those in the normal ones. And the neural activities with significant synchronization were detected in the epileptic mice even without seizure occurrence. Meanwhile, the spikes fire more intensively and Glu level became much higher during the movement of the mice compared to the stationary state. The existing abnormality of neural activities in the epileptic mice are potential factors to induce a seizure. Movement may impact the neural activities and the duration of seizure. The MEA can monitor changes of movement, Glu and neuron discharges synchronously and provides us an effective technology to understand the neuronal disease.