Effect of cortical spreading depression on synaptic transmission of rat hippocampal tissues.
Cortical spreading depression (CSD) is believed to be a putative neuronal mechanism underlying migraine aura and subsequent pain. In vitro and ex vivo/in vitro brain slice techniques were used to investigate CSD effects on the field excitatory postsynaptic potentials (fEPSP) and tetanus-induced long-term potentiation (LTP) in combined rat hippocampus-cortex slices. Induction of CSD in combined hippocampus-cortex slices in which DC negative deflections did not propagate from neocortex to hippocampus significantly augmented fEPSP amplitude and LTP in the hippocampus. Propagation of CSD to the hippocampus resulted in a transient suppression followed by reinstatement of fEPSP with amplitude of pre-CSD levels. LTP was inhibited when DC potential shifts were recorded in the hippocampus. Furthermore, CSD was induced in anaesthetized rats and, thereafter, hippocampal tissues were examined in vitro. LTP was significantly enhanced in hippocampal slices obtained from ipsilateral site to the hemisphere in which CSD was evoked. The results indicate the disturbances of hippocampal synaptic transmission triggered by propagation of CSD. This perturbation of hippocampal synaptic transmission induced by CSD may relate to some symptoms occurring during migraine attacks, such as amnesia and hyperactivity.
Institut für Physiologie I, Westfälische Wilhelms-Universität Münster, Germany.
Brigitta
B
Wernsmann
Hans-Christian
HC
Pape
Erwin-Josef
EJ
Speckmann
Ali
A
Gorji
D000818:Animals; D013181:Cortical Spreading Depression / Q000502:physiology*; D004594:Electrophysiology; D018728:Entorhinal Cortex / Q000166:cytology / Q000502:physiology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology*; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000502:physiology*; D011189:Potassium Chloride / Q000378:metabolism; D051381:Rats; D009435:Synaptic Transmission / Q000502:physiology*
D011189:Potassium Chloride