“Dormant basket cell” hypothesis revisited: Relative vulnerabilities of dentate gyrus mossy cells and inhibitory interneurons after hippocampal status epilepticus in the rat

@article{Sloviter2003DormantBC,
  title={“Dormant basket cell” hypothesis revisited: Relative vulnerabilities of dentate gyrus mossy cells and inhibitory interneurons after hippocampal status epilepticus in the rat},
  author={Robert S Sloviter and Colin A Zappone and Brian D. Harvey and Argyle V. Bumanglag and Roland A. Bender and Michael Frotscher},
  journal={Journal of Comparative Neurology},
  year={2003},
  volume={459}
}
The “dormant basket cell” hypothesis suggests that postinjury hippocampal network hyperexcitability results from the loss of vulnerable neurons that normally excite insult‐resistant inhibitory basket cells. We have reexamined the experimental basis of this hypothesis in light of reports that excitatory hilar mossy cells are not consistently vulnerable and inhibitory basket cells are not consistently seizure resistant. Prolonged afferent stimulation that reliably evoked granule cell discharges… Expand
Kainic acid‐induced recurrent mossy fiber innervation of dentate gyrus inhibitory interneurons: Possible anatomical substrate of granule cell hyperinhibition in chronically epileptic rats
TLDR
It is demonstrated that dentate granule cells are maximally hyperexcitable immediately after SE, prior to mossy fiber sprouting, and that synaptic reorganization following kainate‐induced injury is temporally associated with GABAA receptor‐dependent granule cell hyperinhibition rather than a hypothesized progressive hyperexCitability. Expand
Hilar mossy cell circuitry controlling dentate granule cell excitability
TLDR
It is demonstrated that the extensive elimination of hilar mossy cells causes granule cell hyperexcitability, although the mossy cell loss observed appeared insufficient to cause clinical epilepsy, and it is suggested that different interneuron populations may mediate mossycell-induced translamellar lateral inhibition and intralamellAR recurrent inhibition. Expand
Translamellar Disinhibition in the Rat Hippocampal Dentate Gyrus after Seizure-Induced Degeneration of Vulnerable Hilar Neurons
TLDR
The findings suggest that translamellar disinhibition may result from the loss of vulnerable, longitudinally projecting mossy cells and may represent a network-level mechanism underlying postinjury hippocampal dysfunction and epileptic network hyperexcitability. Expand
Dysfunction of the Dentate Basket Cell Circuit in a Rat Model of Temporal Lobe Epilepsy
TLDR
Dysfunction of the dentate basket cell circuit could contribute to hyperexcitability and seizures in epileptic animals, according to findings. Expand
Synaptic Reorganization of Inhibitory Hilar Interneuron Circuitry after Traumatic Brain Injury in Mice
TLDR
It is suggested that excitatory drive to surviving hilar GABA neurons is enhanced by convergent input from both pyramidal and granule cells, but synaptic inhibition ofgranule cells is not fully restored after injury. Expand
Hilar Mossy Cell Degeneration Causes Transient Dentate Granule Cell Hyperexcitability and Impaired Pattern Separation
TLDR
The results indicate that the net effect of mossy cell excitation is to inhibit granule cell activity and enable dentate pattern separation. Expand
Morphologic integration of hilar ectopic granule cells into dentate gyrus circuitry in the pilocarpine model of temporal lobe epilepsy
TLDR
HEGCs with burst capability had less well‐branched apical dendrites than nonbursting HEGCs, their dendrite features were more likely to be confined to the hilus, and some exhibited dendritic features similar to those of immature granule cells. Expand
Adaptive mossy cell circuit plasticity after status epilepticus
TLDR
It is suggested that mossy cell outputs reorganize following seizures, increasing their net inhibitory effect in the hippocampus. Expand
High ratio of synaptic excitation to synaptic inhibition in hilar ectopic granule cells of pilocarpine-treated rats.
TLDR
Electron microscopic studies indicated that HEGCs receive more recurrent mossy fiber innervation than normotopic granule cells in the same animals but receive much less inhibitory innervation, and a high ratio of excitatory to inhibitory synaptic function probably accounts for the hyperexcitability of H EGCs. Expand
Rapid Deletion of Mossy Cells Does Not Result in a Hyperexcitable Dentate Gyrus: Implications for Epileptogenesis
TLDR
A fast, cell-specific ablation technique that allowed the targeted lesioning of either mossy cells or GABAergic interneurons in horizontal as well as axial (longitudinal) slices of the hippocampus demonstrated that mossy cell deletion consistently decreased the excitability of granule cells to perforant path stimulation both within and outside of the lamella where the mossycell ablation took place. Expand
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