Simultaneous glutamate recordings in the frontal cortex network with multisite biomorphic microelectrodes: New tools for ADHD research

• We developed ceramic-based, dual-sided biomorphic 8-site biosensors.
• Dual-sided design may help optimize spatial detection of neurotransmitters.
• In vitro calibrations show glutamate responses only on glutamate-sensitive sites.
• Simultaneous glutamate detection from four cortical locations in freely moving rats.

BackgroundThe aberrant regulation of glutamate has been implicated in numerous psychiatric disorders including drug addiction and attention-deficit/hyperactivity disorder. To understand glutamate signaling and its role in facilitating disease, tools to directly measure glutamate in a complex, neural network are needed.New methodThe development of a ceramic-based, dual-sided, biomorphic microelectrode array with four recording sites on each side to facilitate a more detailed measurement of glutamate in awake, behaving rodents.ResultsIn vitro calibrations of these biosensors showed selective and specific responses to glutamate. In awake rats, these biomorphic electrode arrays enabled the concurrent evaluation of glutamate in a network, the frontal cortex: including the cingulate, prelimbic, infralimbic and dorsal peduncle regions. Regions within the frontal cortex exhibited varying phasic glutamate patterns in awake animals.Comparison with existing method: Existing methodologies to measure glutamate neurotransmission employ single-sided biosensors or biosensors capable of measuring neurochemicals at only one location in space.ConclusionsMulti-site, biomorphic neurochemical biosensors provide a method for simultaneously measuring glutamate in multiple areas of a neural network in the brain.

Figure optionsDownload as PowerPoint slide