| Autor: |
Tolner, E.A., Kloosterman, F., Kalitzin, S., Lopes da Silva, F.H., Gorter, J.A. |
| Přispěvatelé: |
Cellular and Computational Neuroscience (SILS, FNWI) |
| Rok vydání: |
2005 |
| Předmět: |
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| Zdroj: |
Epilepsia, 45(5), 72-81. Wiley-Blackwell |
| ISSN: |
0013-9580 |
| Popis: |
We investigated whether the functional network properties of the medial entorhinal area (MEA) of the entorhinal cortex were altered in a rat model of chronic epilepsy that is characterized by extensive cell loss in MEA layer III. METHODS: Responses were evoked in the entorhinal cortex by electrical stimulation of the subiculum in anesthetized chronic epileptic rats, 2-4 months after status epilepticus, induced by systemic kainate (KA) injections. Laminar field potentials were measured using a 16-channel silicon probe that covered all six layers of the MEA; an estimate of the local transmembrane currents was made using current source density analysis. RESULTS: Double-pulse stimulation of the subiculum evoked responses in deep and superficial layers of the MEA in control and KA rats. A current sink in layer I and at the border of layer I and II that was induced by antidromic activation of MEA-II, was much more prominent in KA rats with extensive neuronal loss in MEA-III than in control rats or KA rats with minor MEA-III loss. Furthermore, KA rats that displayed MEA-III loss presented a series of oscillations induced by subicular stimulation in the beta/gamma-frequency range (20-100 Hz), which were confined to superficial layers of MEA. These oscillations were never observed in control rats or KA rats with minor MEA-III loss. CONCLUSIONS: These results indicate that the observed alterations in the superficial MEA responses to subiculum stimulation and the occurrence of beta/gamma-oscillations are related phenomena, which are a consequence of altered and impaired inhibition within these MEA layers in chronic epileptic rats. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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