ULTRASTRUCTURAL-STUDY OF MORPHOLOGICAL BASES OF THE LONG-LASTING POTENTIATION BY THE FREEZE-SUBSTITUTION METHOD

  • 1 January 1980
    • journal article
    • research article
    • Vol. 22  (1) , 20-+
Abstract
Some morphological features of the pyramidal neurons which depend on their physiological state were studied in the CA3 area of the guinea pig hippocampal slices by the freeze-substitution method. This method provided a better possibility to observe certain visible structural changes in the majority of fiber synapses in stratum lucidum after the rhythmic stimulation of dentate gyrus, compared to conventional EM. The width of the spine stalks during the long-lasting potentiation in the tissue processed by the freeze-substitution method increased by 66%, below the 50% increase in conventional preparations. A correlation between changes in the postsynaptic densities and the physiological state of synapses was checked. A 2-fold increase in the width of postsynaptic densities without changes in their length was found.