Sprouting of Mossy Fibers in the Hippocampus of Epileptic Human and Rat
Epilepsy is a neurological disorder characterized by the presence of recurrent seizures and during the interictal periods, synchronous activation of a neuronal cell group. Numerous reports have suggested that there is common underlying mechanisms with long term potentiation; i.e. the kindling model of epilepsy induced by stimulation of the entorhinal cortex is associated with a synaptic potentiation at the perforant pathway-granule cell synapse (Goddard et al. 1969); moreover, as in LTP induction, these synaptic potentiation involves the activation of NMDA receptors (Mody and Heinemann 1987; Ben-Ari and Gho 1987). The hypothesis that the morphological substrate of epilepsy resides in the establishment of new aberrant connections has been frequently considered. Morphological evidence has recently been obtained for the hippocampal mossy fibers which originate in the dentate granule cells and project to the giant pyramidal neurons of CA3 area. Thus, mossy fibers sprout and establish aberrant connections both in kindling epilepsy (Sutula et al. 1988, Represa et al 1989) and in childhood epilepsy (Represa et al 1989 b).
KeywordsMossy Fiber Kainic Acid Childhood Epilepsy Synaptic Potentiation Epileptic Child
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