The subiculum: a potential site of ictogenesis in human temporal lobe epilepsy.
OBJECTIVE
This study determines synaptic and intrinsic alterations of subicular pyramidal cells that are associated with activity recorded in patients suffering from temporal lobe epilepsy.


METHODS
Electroencephalograms with sphenoidal electrodes were correlated with in vitro single cell recordings of subicular pyramidal cells from the corresponding resected epileptic tissue. We determined alterations of synaptic and intrinsic properties of subicular pyramidal cells that accompany spontaneous rhythmic activity in human sclerotic and nonsclerotic epileptic tissue.


RESULTS
We found that in sclerotic, but also in nonsclerotic hippocampal tissue, the subiculum showed cellular and synaptic changes that were associated with spontaneous rhythmic activity correlated to the occurrence and frequency of interictal discharges recorded in the electroencephalograms of the corresponding patients.


CONCLUSIONS
Even though Ammon's horn sclerosis (AHS) in resected hippocampi from patients suffering from temporal lobe epilepsy has important prognostic implications for freedom from seizures postoperatively, we report here that both synaptic and intrinsic alterations enhance seizure susceptibility of the subiculum also in the absence of classical AHS.
Neuroscience Research Center of the Charité, Humboldt University Berlin, Berlin, Germany.
Christian
C
Wozny
Andreas
A
Knopp
Thomas-Nicolas
TN
Lehmann
Uwe
U
Heinemann
Joachim
J
Behr
D000328:Adult; D000368:Aged; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000502:physiology; D008839:Microelectrodes; D008875:Middle Aged; D017966:Pyramidal Cells / Q000473:pathology / Q000503:physiopathology; D012598:Sclerosis / Q000473:pathology; D009435:Synaptic Transmission / Q000502:physiology