Loss of long-term potentiation at hippocampal output synapses in experimental temporal lobe epilepsy

Sabine Grosser, Nadine Buck, Karl Heinz Braunewell, Kate E. Gilling, Christian Wozny, Pawel Fidzinski, Joachim Behr

Research output: Contribution to journalArticle

Abstract

Patients suffering from temporal lobe epilepsy (TLE) show severe problems in hippocampus dependent memory consolidation. Memory consolidation strongly depends on an intact dialog between the hippocampus and neocortical structures. Deficits in hippocampal signal transmission are known to provoke disturbances in memory formation. In the present study, we investigate changes of synaptic plasticity at hippocampal output structures in an experimental animal model of TLE. In pilocarpine-treated rats, we found suppressed long-term potentiation (LTP) in hippocampal and parahippocampal regions such as the subiculum and the entorhinal cortex (EC). Subsequently we focused on the subiculum, serving as the major relay station between the hippocampus proper and downstream structures. In control animals, subicular pyramidal cells express different forms of LTP depending on their intrinsic firing pattern. In line with our extracellular recordings, we could show that LTP could only be induced in a minority of subicular pyramidal neurons. We demonstrate that a well-characterized cAMP-dependent signaling pathway involved in presynaptic forms of LTP is perturbed in pilocarpine-treated animals. Our findings suggest that in TLE, disturbances of synaptic plasticity may influence the information flow between the hippocampus and the neocortex.

Original languageEnglish
Article number143
Number of pages11
JournalFrontiers in Molecular Neuroscience
Volume13
DOIs
Publication statusPublished - 28 Aug 2020

Keywords

  • hippocampus
  • long-term potentiation
  • subiculum
  • synaptic plasticitiy
  • temporal lobe epilepsy (TLE)

Cite this

Grosser, S., Buck, N., Braunewell, K. H., Gilling, K. E., Wozny, C., Fidzinski, P., & Behr, J. (2020). Loss of long-term potentiation at hippocampal output synapses in experimental temporal lobe epilepsy. Frontiers in Molecular Neuroscience, 13, [143]. https://doi.org/10.3389/fnmol.2020.00143