The inactivation of rodent brain enzymes in vivo using high-intensity microwave irradiation

Exposure to high-intensity microwave irradiation is being widely used in neurobiology as a technique for simultaneously sacrificing animals and inactivating brain enzymes, thereby eliminating postmortem artifacts in many heat-stable substrates such as acetylcholine, L-DOPA, gamma aminobutyric acid, cyclic AMP, cyclic GMP, and certain components of the glycolytic pathway. This technique permits dissection of the brain into specific regions-a distinct advantage over quickfreezing methods of sacrifice. One disadvantage of using 2450 MHz is the requirement to immobilize the subject during sacrifice; this requirement might be eliminated at a lower frequency such as 986 MHz. To use the technique reliably the experimenter must monitor and control power source output and frequency, impedance matching with the load, and incident and reflected power. The experimenter must demonstrate the heat stability of the substrate to be measured and study the heat lability characteristics of the enzyme to be inactivated, demonstrating adequacy of inactivation. When the above requirements are met, the microwave enzyme inactivation technique has broad applicability in the neurosciences.