ULTRASTRUCTURAL FEATURES OF THE ISOLATED GUINEA-PIG BRAIN MAINTAINED IN-VITRO BY ARTERIAL PERFUSION

The morphological features of cerebral tissue in the isolated guinea-p ig brain maintained in vitro by arterial perfusion are described. Ligh t and electron microscopic analysis of the thalamus, the somatosensory cortex and the limbic cortices (hippocampus, piriform and entorhinal cortices) was performed after different periods of incubation in vitro (1, 7 and 12 h), in parallel with an electrophysiological study. The morphological analysis showed that neuronal elements retained their no rmal appearance at both cellular and subcellular level in the examined brain regions up to an incubation period of 12 h. Immunoreactivity fo r GABA was also preserved for up to 12 h of in vitro perfusion. Vasoge nic edema and perivascular extracellular swelling appeared after 7 h, together with signs of progressive astrocytic deterioration. These fin dings show that normal electrophysiological recordings correlate with good anatomical preservation of the isolated guinea-pig brain preparat ion after prolonged times of arterial in vitro perfusion.