A Novel Microbiosensor Microarray for Continuous Ex Vivo Monitoring of Gamma-Aminobutyric Acid in Real-Time

Abstract

Gamma-aminobutyric acid(GABA) is the major inhibitory neurotransmitter that is essential for normal brain function. It is involved in multiple neuronal activities, including plasticity, information processing and network synchronization.Abnormal GABA levels result to severe brain disorders and therefore GABA has been the target of a wide range of drug therapeutics. GABA being non-electroactive is challenging to detect in real-time. Here, we report the design and implementation of a GABA microarray probe that operates on a newly conceived principle. It consists of two microbiosensors, one for Glutamate (Glu) and one for GABA detection, modified with glutamate oxidase and GABASE enzymes, respectively. GABA and Glu can be detected continuously in real-time in-vitro and ex-vivo and without the addition of any externally applied reagents. This method yielded higher sensitivity and it was also successfully tested in an adult rat brain slice preparation. These initial results demonstrate that the developed GABA probe has the potential to become powerful neuro-scientific tool that could be employed in the future for in vivo studies. Moreover, we will discuss the recent findings from the optimization of the probe by modifying enzyme concentration and process automation with micro-spotting technique and the changes in the GLU-GABA concentrations in different parts of the brain (thalamus, hippocampus, cortex) for epilepsy disease model. Figure 1