scholarly journals Blockade of excitatory synaptogenesis with proximal dendrites of dentate granule cells following rapamycin treatment in a mouse model of temporal lobe epilepsy

2014 ◽  
Vol 523 (2) ◽  
pp. 281-297 ◽  
Author(s):  
Ruth Yamawaki ◽  
Khushdev Thind ◽  
Paul S. Buckmaster
Keyword(s):  
Mouse Model ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Granule Cells ◽  
Rapamycin Treatment ◽  
Dentate Granule Cells

scholarly journals Dentate granule cells form novel basal dendrites in a rat model of temporal lobe epilepsy

Neuroscience ◽  
1998 ◽  
Vol 86 (1) ◽  
pp. 109-120 ◽  
Author(s):  
I Spigelman ◽  
X.-X Yan ◽  
A Obenaus ◽  
E.Y.-S Lee ◽  
C.G Wasterlain ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Rat Model ◽  
Granule Cells ◽  
Dentate Granule Cells ◽  
Basal Dendrites

Loss of Calbindin-D28K immunoreactivity from dentate granule cells in human temporal lobe epilepsy

Neuroscience ◽  
1997 ◽  
Vol 76 (2) ◽  
pp. 377-385 ◽  
Author(s):  
Zs. Maglóczky ◽  
P. Halász ◽  
J. Vajda ◽  
S. Czirják ◽  
T.F. Freund
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Granule Cells ◽  
Dentate Granule Cells ◽  
Calbindin D28k ◽  
Human Temporal Lobe

scholarly journals Intrinsic neurophysiological properties of hilar ectopic and normotopic dentate granule cells in human temporal lobe epilepsy and a rat model

2015 ◽  
Vol 113 (4) ◽  
pp. 1184-1194 ◽  
Author(s):  
A. L. Althaus ◽  
O. Sagher ◽  
J. M. Parent ◽  
G. G. Murphy
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Granule Cells ◽  
Salient Feature ◽  
Granule Cell Layer ◽  
Disease Stage ◽  
Resting Membrane Potential ◽  
Firing Rates ◽  
Dentate Granule Cells ◽  
Human Temporal Lobe

Hilar ectopic dentate granule cells (DGCs) are a salient feature of aberrant plasticity in human temporal lobe epilepsy (TLE) and most rodent models of the disease. Recent evidence from rodent TLE models suggests that hilar ectopic DGCs contribute to hyperexcitability within the epileptic hippocampal network. Here we investigate the intrinsic excitability of DGCs from humans with TLE and the rat pilocarpine TLE model with the objective of comparing the neurophysiology of hilar ectopic DGCs to their normotopic counterparts in the granule cell layer (GCL). We recorded from 36 GCL and 7 hilar DGCs from human TLE tissue. Compared with GCL DGCs, hilar DGCs in patient tissue exhibited lower action potential (AP) firing rates, more depolarized AP threshold, and differed in single AP waveform, consistent with an overall decrease in excitability. To evaluate the intrinsic neurophysiology of hilar ectopic DGCs, we made recordings from retrovirus-birthdated, adult-born DGCs 2–4 mo after pilocarpine-induced status epilepticus or sham treatment in rats. Hilar DGCs from epileptic rats exhibited higher AP firing rates than normotopic DGCs from epileptic or control animals. They also displayed more depolarized resting membrane potential and wider AP waveforms, indicating an overall increase in excitability. The contrasting findings between disease and disease model may reflect differences between the late-stage disease tissue available from human surgical specimens and the earlier disease stage examined in the rat TLE model. These data represent the first neurophysiological characterization of ectopic DGCs from human hippocampus and prospectively birthdated ectopic DGCs in a rodent TLE model.

Temporal Lobe Epilepsy

2005 ◽  
Vol 103 (4) ◽  
pp. 768-769 ◽  
Author(s):  
Ross P. Carne ◽  
Terence J. O'Brien ◽  
Christine J. Kilpatrick ◽  
Lachlan R. MacGregor ◽  
Rodney J. Hicks ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Clinical Features ◽  
Temporal Lobe ◽  
Granule Cells ◽  
Hippocampal Slices ◽  
Mr Images ◽  
Content Type ◽  
Dentate Granule Cells ◽  
Fine Print

Abstract Object. The syndrome of medial temporal lobe epilepsy (MTLE) may occur in patients in whom magnetic resonance (MR) images demonstrate normal findings. In these patients, there is no evidence of hippocampal sclerosis on neuroimaging, and histopathological examination of the resected hippocampus does not reveal significant neuron loss. In this paper the authors describe the distinct clinical features of this MTLE subtype, referred to as paradoxical temporal lobe epilepsy (PTLE). Methods. The authors selected 12 consecutive patients with preoperative findings consistent with MTLE in whom MR imaging did not demonstrate any hippocampal abnormality. Onset of hippocampal seizure was confirmed by long-term intracranial monitoring. There were six female and six male patients with a mean age of 32 ± 11 years (mean ± standard deviation [SD]) at presentation. These patients' seizure histories, available hippocampal volumetric measurements, and hippocampal cell densities in different subfields were reviewed. Sharp electrode recordings from dentate granule cells that had been maintained in hippocampal slices provided a measure of excitation and inhibition in the tissue. We compared these data with those of a cohort of 50 randomly selected patients who underwent anteromedial temporal resection for medial temporal sclerosis (MTS) during the same time period (1987–1999). The durations of follow up (means ± SDs) for the PTLE and MTS groups were 51 ± 59 months and 88 ± 44 months, respectively. A history of febrile seizure was present less frequently in the PTLE group (8%) than in the MTS group (34%). Other risk factors for epilepsy such as trauma, meningoencephalitis, or perinatal injuries were present more frequently in the PTLE group (50%) than in the MTS cohort (36%). In patients in the PTLE group the first seizure occurred later in life (mean age at seizure onset 14 years in the PTLE group compared with 9 years in the MTS group, p = 0.09). Ten patients (83%) in the PTLE cohort and 23 patients (46%) in the MTLE cohort had secondary generalization of their seizures. Among patients with PTLE, volumetric measurements (five patients) and randomized blinded visual inspection (seven patients) of the bilateral hippocampi revealed no atrophy and no increased T2 signal change on preoperative MR images. All patients with PTLE underwent anteromedial temporal resection (amygdalohippocampectomy, in five patients on the left side and in seven on the right side). Electrophysiological studies of hippocampal slices demonstrated that dentate granule cells from patients with PTLE were significantly less excitable than those from patients with MTS. The mean pyramidal cell loss in the CA1 subfield in patients in the PTLE group was 20% (range 0–59%) and that in patients in the MTS group was 75% (range 41–90%) (p < 0.001). Maximal neuron loss (mean loss 38%) occurred in the CA4 region in six patients with PTLE (end folium sclerosis). At the last follow-up examination, six patients (50%) in the PTLE group were seizure free compared with 38 patients (76%) in the MTS group. Conclusions. Clinical PTLE is a distinct syndrome with clinical features and surgical outcomes different from those of MTS.

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