DIRECT OBSERVATION OF NEUROTOXICITY IN BRAIN-SLICES WITH INFRARED VIDEOMICROSCOPY

We employed the novel technique of infrared videomicroscopy to study t he morphological changes induced by the neurotoxicity of high concentr ations of L-glutamate and by anoxia. The infrared videomicroscopy syst em described uses an inverted microscope and employs a combination of infrared illumination, differential interference contrast (DIC) and co ntrast enhancement by video. With this system, we were able to observe swelling of neurons 50 mu m deep in rat neocortical slices after bath application of glutamatergic agonists or during anoxia. By recording in time lapse mode it was possible to visualize the dynamics of cell s welling and to demonstrate neuroprotection by glutamatergic antagonist s. The method may be of use in screening of potential neuroprotective drugs for stroke therapy.