Long-lasting Transneuronal Changes in Rat Dentate Granule Cell Dendrites after Entorhinal Cortex Lesion. A Combined Intracellular Injection and Electron Microscopy Study

摘要: Following entorhinal cortex lesion, inhibitory hippocampal neurons show a persistent rarefication of those dendrites formally receiving input. Physiological data indicate long lasting disequilibrium inhibition and excitation in the de-entorhinated hippocampus. We analyzed intracellularly-stained dendritic tree excitatory rat granule cells. Granule cells controls animals surviving 2, 8, 60 270 days after unilateral lesion were impaled. Dendrites control typical shape, traced to fissure complete dye filling was ascertained by EM-analysis. Conversely, following lesioning, only rarely seen extend into outer portions molecular layer architecture became significantly rarefied. Sixty post-lesion, intracellularly filled extending middle surrounded cell clusters resembling glia. Some these contained neuronally applied dye, suggesting close association cytosolic compartments with altered dendrites. These observed alterations exceed process sprouting de novo synaptogenesis remaining afference for periods time. The morphology both seems require specific input from cortex. Moreover, afferents is apparently not sufficient compensate this loss