Effect of microwave irradiation on brain tissue structure and catecholamine distribution tech./dosim.

During the course of studies on the usefulness of microwave irradiation for rapid inactivation of enzymes for assaying regional catecholamines in animal brains, questions have been raised regarding the possibility of tissue damage resulting from irradiation, as well as transformation and cell disruption followed by the flowing out of neurotransmitters. To find a response to these questions, light and electron microscopic examinations were carried out on corpus striatum and locus coeruleus sections and compared with sections obtained in a previous decapitation study.

• animal
• rat/Sprague-Dawley
• partial body: head

The interface of the striatum and the cortex showed no trace of tissue breakdown. Transformed cells, vacuolation, and indications of pycnotic degeneration in the nucleus were observed in locus coeruleus after exposure, but the shapes of these cells were well defined. Electron microscopic photographs of synapses in the same area showed membrane damage after irradiation for 5 s at 1.3 kW, but synaptic vesicles were clearly defined. The authors concluded that the increased catecholamine levels (as reported in previous studies) were not the result of tissue disruption following rapid heating of the brain by irradiation.