The mossy fiber axons of both the developing and adult dentate gyrus express the highly polysialylated form of neural cell adhesion molecule (NCAM) as they innervate the proximal apical dendrites of pyramidal cells in the CA3 region of the hippocampus. The present study used polysialic acid (PSA)-deficient and NCAM mutant mice to evaluate the role of PSA in mossy fiber development. The results ...

Synapses of the hippocampal mossy fiber pathway exhibit several characteristic features, including a unique form of long-term potentiation that does not require activation of the N-methyl-D-aspartate receptor by glutamate, a complex postsynaptic architecture, and sprouting in response to seizures. However, these connections have proven difficult to study in hippocampal slices because of their r...

Status epilepticus (SE) is a severe neurological condition that can result in brain damage. In animals, SE is associated with cell loss and aberrant synaptogenesis. These pathological processes appear to be activity-dependent and may continue after the SE has ended. We postulated that suppression of electrical activity following SE at the site of the epileptic focus will reduce seizure-induced ...

Neonatal Borna disease (NBD) virus infection in the Lewis rat results in life-long viral persistence and causes behavioral and neurodevelopmental abnormalities. A hallmark of the disorder is progressive loss of cerebellar Purkinje and dentate gyrus granule cells. Findings of increased brain metallothionein-I and -II (MT-I/-II) mRNA expression in cDNA microarray experiments led us to investigate...

Repeated seizures induce mossy fiber axon sprouting, which reorganizes synaptic connectivity in the dentate gyrus. To examine the possibility that sprouted mossy fiber axons may form recurrent excitatory circuits, connectivity between granule cells in the dentate gyrus was examined in transverse hippocampal slices from normal rats and epileptic rats that experienced seizures induced by kindling...

PURPOSE To study the development of epilepsy following hypoxia-induced neonatal seizures in Long-Evans rats and to establish the presence of spontaneous seizures in this model of early life seizures. METHODS Long-Evans rat pups were subjected to hypoxia-induced neonatal seizures at postnatal day 10 (P10). Epidural cortical electroencephalography (EEG) and hippocampal depth electrodes were use...

Neural firing patterns are an essential determinant of normal axon terminal growth and synaptic connectivity in developing afferent pathways, but the trophic role of synchronous activity in associative neural networks is less well defined. We examined the ontogeny of inherited synchronous hippocampal network discharges and mossy fiber innervation patterns at sequential stages of development in ...

background and objective: temporal lobe epilepsy is hallmarked with neuronal degeneration in some areas of hippocampus and mossy fiber sprouting in dentate area. considering some evidences on neuroprotective and antioxidant activity of silymarin (sm), this study was undertaken to evaluate the preventive effect of this agent on structural changes in hippocampus of kainate-epileptic rats. materia...

Chronic administration of electroconvulsive seizures (ECS), one of the most effective treatments for depression, induces sprouting of the mossy fibers in the hippocampus. This sprouting requires chronic ECS administration and appears to occur in the absence of hilar neuronal loss. Dynamic regulation of cytoarchitecture plays a vital role in such profound alterations of neuronal morphology. In p...

Intracerebroventricular kainate administration in rat, a model of temporal lobe epilepsy (TLE), causes degeneration of the hippocampal CA3 pyramidal and dentate hilar neurons. This leads to a robust but aberrant sprouting of the granule cell axons (mossy fibers) into the dentate supragranular layer and the CA3 stratum oriens. Because this plasticity is linked to an increased seizure susceptibil...