Plastic neuronal probes for implantation in cortical and subcortical areas of the rat brain

Esma Ismailova (1), Thomas Doublet (1,2,3), Dion Khodagholy (1), Pascale Quilichini (2), Antoine Ghestem (2), Sang Yoon Yang (4), Christophe Bernard (2) and George G. Malliaras (1) 1 BioELectronics lab, Centre Microélectronique de Provence Ecole Nationale Supérieure des Mines de Saint Etienne, FRANCE 2 INSERM U 751, Université de la Méditerranée, Faculté de Médecine La Timone,FRANCE 3 MICROVITAE Technologies, Pôle d'Activité Y. Morandat, FRANCE 4 Department of Materials Science and Engineering, Cornell University Ithaca, NY 14853-1501, USA

Abstract: We discuss the fabrication of flexible implantable probes for recording neuronal activity in the rat brain. We fabricated such probes bearing 12 platinum electrodes, using polyimide as a substrate and SU-8 as an insulation layer. The fabrication process was simplified through the use of laser ablation to define the probe outline. The probes showed not only good mechanical flexibility, but also the required stiffness for implantation. Histology results and electrical recordings of neuronal activity lend support to the idea that the combination of polyimide and SU-8 represents a good choice of materials for the fabrication of implantable neuronal probes.

 

One cornerstone event during epileptogenesis is the occurrence of the first spontaneous seizure (SZ1). It is therefore important to identify biomarkers of the network alterations leading to SZ1. In experimental models of temporal lobe epilepsy (TLE), interictal-like activity (ILA) precedes SZ1 by several days. The goal of this study was to determine whether ILA dynamics bore electrophysiological features signing the impeding transition to SZ1