Abstracts

Rationale: Technological progress in intracranial electroencephalography has not only extended the research submission from macroscale depiction of regional brain functions to microscale analysis of neural activity, but also extended clinical application from epilepsy surgery to neural prostheses. The sticking point is the availability of sub-millimeter microelectrode for neural recording. Although validation and optimization of the different material and structure microelectrodes are basically prior to listing, it is difficult to have in vivo tests on human brain repeatedly. Methods: Our first-generation microelectrode array is consisted of 4 silicon shafts and 4 platinum recording sites on each shaft. We maintain the neural activity of mice brain or resected human brain block in constant temperature, oxygenated artificial cerebrospinal fluid. Mice brain was obtained after induction of convulsive seizure by intraperitoneal injection of pentylenetetrazol. Human brain tissue was obtained from patient underwent epilepsy surgery. The microelectrode was inserted into the brain tissue via a controlled compact linear actuator. Responsive pressure curve of microelectrode during penetrating pia mater was recorded for adjusting the optimal insertion speed to reduce tissue damage. Impedance of each recording sites was recorded before and after insertion process. After that, brain tissue was stained to verify the studied areas. Results: Clear near field potentials and spikes could be recorded at various recording sites. By the obtained information, we redesign following generation microelectrode array to achieve improvement of electrode attaching stability and higher signal to noise ratio. Conclusions: Here, we report the development of an acute ex vivo human brain neural recording system and demonstrate the preliminary neural recordings of mice and resected human brain tissue via the microelectrode array. Our work represents one translation template for research uses and testing feasibility of developing biomedical devices before in vivo human brain study. The acute ex vivo brain neural recording system enable emerging implantable microelectrode array capable of addressing important issues in analysis of epileptic neural signals. Supported: NSC 101-2220-E-303-001-Tzu-Chi Hospital Matching Grants 1, NSC 101-2220-E-303-001, NSC support for the Center for Dynamical Biomarkers and Translational Medicine, National Central University, Taiwan (NSC 100-2911-I-008-001) and Aim for the Top University Plan of the National Chiao Tung University and Ministry of Education, Taiwan.