Measuring Brain Glutamate Levels Under Anesthesia in Neonatal Piglets Using a Microelectrode Array
Transcript
Secure an anesthetized neonatal piglet to a stereotaxic frame.
Make a midline incision to reveal the skull.
Remove a portion of the skull, then remove the dura to access the brain.
Fix a microelectrode array, or MEA to the stereotaxic frame.
The MEA consists of a rigid shaft and recording sites, including glutamate-sensitive sites coated with glutamate oxidase and sentinel sites coated with an inactive protein matrix.
Position the MEA vertically over the surgical site and place a pseudo-reference electrode under the scalp for a stable baseline voltage reference.
Insert the MEA into the brain region of interest and initiate measurement.
Glutamate oxidase on the recording sites converts extracellular brain glutamate to hydrogen peroxide, which undergoes electrochemical oxidation at the electrode surface, generating current.
The sentinel sites measure background noise.
Normalize the glutamate-sensitive site signals to the sentinel site signals to measure the brain glutamate levels under anesthesia.
