On the origin of interictal activity in human temporal lobe epilepsy in vitro.
The origin and mechanisms of human interictal epileptic discharges remain unclear. Here, we describe a spontaneous, rhythmic activity initiated in the subiculum of slices from patients with temporal lobe epilepsy. Synchronous events were similar to interictal discharges of patient electroencephalograms. They were suppressed by antagonists of either glutamatergic or gamma-aminobutyric acid (GABA)-ergic signaling. The network of neurons discharging during population events comprises both subicular interneurons and a subgroup of pyramidal cells. In these pyramidal cells, GABAergic synaptic events reversed at depolarized potentials. Depolarizing GABAergic responses in neurons downstream to the sclerotic CA1 region contribute to human interictal activity.
Cohen
Ivan
I
EMI 0224, CHU Pitié-Salpêtrière, Université Paris VI, 75013 Paris, France.
Navarro
Vincent
V
Clemenceau
Stéphane
S
Baulac
Michel
M
Miles
Richard
R
D000200:Action Potentials; D000328:Adult; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D066298:In Vitro Techniques; D007395:Interneurons / Q000502:physiology*; D008564:Membrane Potentials; D008839:Microelectrodes; D008875:Middle Aged; D009412:Nerve Fibers / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology; D017966:Pyramidal Cells / Q000502:physiology*; D015398:Signal Transduction; D009435:Synaptic Transmission; D013702:Temporal Lobe / Q000503:physiopathology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D018691:Excitatory Amino Acid Antagonists; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid