Fig. 3: The sensing and stimulation function of deep brain-machine interfaces.
A Microelectrode, local field potential and examples of electrochemical technologies. Left: Amperometry is used to determine glutamate levels. In this scenario, local glutamate is converted to H2O2 by glutamate oxidase. Subsequently, H2O2 breaks down into two hydrogen molecules and oxygen, releasing two electrons that boost the current recorded in the biosensor (platinum wire). Any interfering molecules are effectively blocked by Nafion. Right: Fast scan cyclic voltammetry determines dopamine. Dopamine undergoes a potential change cycle from −0.4 V to +1.3 V and back to −0.4 V, during which dopamine and dopamine-o-quinone mutually convert, promoting electron transfer. This electron transfer causes distinctive disturbances in the original voltammogram, facilitating the identification of specific neurotransmitters. a-KG: α–ketoglutarate; BSA: Bovine serum albumin; e-: electrons; DA: dopamine; DOQ: Dopamine-o-quinone; E (^): Varied voltage; Glu-Ox: Glutamate oxidase; Glut: glutaraldehyde; PT: Platinum wire. Image created with BioRender.com, with permission. This figure is protected by Copyright, is owned by Journal of Neurosurgery Publishing Group (JNSPG at thejns.org) and is used with permission only within this document. Permission to use it otherwise must be secured from JNSPG. Full text of the article containing the original figure is available at https://doi.org/10.3171/2010.5.FOCUS10110. B Different stimulation methods and devices. Image created with BioRender.com, with permission.
