DOES MICROWAVE IRRADIATION HAVE OTHER THAN THERMAL EFFECTS ON HISTOLOGICAL STAINING OF THE MAMMALIAN CNS - A LIGHT-MICROSCOPIC STUDY OF MICROWAVE STIMULATED STAINING UNDER ISOTHERMAL CONDITIONS IN MAN AND RAT

The question whether or not microwave irradiation exerts other than th ermal effects on histological staining is still a matter of controvers y. The present study was undertaken to reveal or reject such a so far hypothetical non-thermal irradiation effect. A device was developed, w hich enables exposure of histological sections or tissue pieces to mic rowave irradiation under isothermal conditions, i.e. with synchronous removal of the internal heat produced. Three classical neuroanatomical staining methods were tested on human and rat CNS. As control, identi cal procedures were performed without simultaneous microwave irradiati on. The experiments were performed at three different temperature leve ls ranging from 5 to 50-degrees-C. In none of the cases studied was a light microscopically appreciable difference observed between the micr owave and non-microwave versions of a stain at the same temperature. T he hypothesis of a separate non-thermal effect of microwave irradiatio n on histological staining is therefore rejected.