Interleukin-6 inhibits long-term potentiation in rat hippocampal slices.
The effects of recombinant human interleukin-6 (rhIL-6) on long-term potentiation (LTP) induced in the Schaffer collateral/commissural-CA1 pathway were examined using rat hippocampal slices. Field excitatory postsynaptic potential was recorded in the stratum radiatum of the CA1 region. Ten-min applications of rhIL-6 (50-2000 U/ml), started 5 min before the tetanus, significantly inhibited the induction of LTP, and in high doses of rhIL-6 also inhibited short-term potentiation (over 200 U/ml) and post-tetanic potentiation (over 500 U/ml). The effects of rhIL-6 (500 U/ml) were completely abolished by the preincubation of the slices with monoclonal anti-IL-6 receptor antibody (16 microg/ml) for 2 h. Heat-inactivated rhIL-6 had no effect on the synaptic potentiation. RhIL-6 affected neither the previously established LTP nor the basal synaptic transmission. These findings indicated that rhIL-6 modulated synaptic potentiation through the IL-6 receptor-mediated process in the hippocampus, probably by affecting post- and presynaptic sites in the CA1 region. The possible mechanisms of the IL-6-induced suppression of the synaptic potentiation were discussed.
Li
A J
AJ
Department of Physiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Katafuchi
T
T
Oda
S
S
Hori
T
T
Oomura
Y
Y
D000200:Action Potentials; D000818:Animals; D000911:Antibodies, Monoclonal; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D015850:Interleukin-6 / Q000494:pharmacology*; D017774:Long-Term Potentiation / Q000187:drug effects*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins; D009435:Synaptic Transmission / Q000187:drug effects
D000911:Antibodies, Monoclonal; D015850:Interleukin-6; D011994:Recombinant Proteins