Effects of adenosine receptors on the synaptic and EPSP-spike components of long-term potentiation and depotentiation in the guinea-pig hippocampus - PubMed (original) (raw)

A, SRCs of the S-EPSP and A-PS 20 min before (control, •), 20 min after the tetanus (LTP, ▴), and 60 min after the LFS (DP, □). The left, middle, and right graphs, respectively, show typical examples of the SRCs before and after tetanus, and after the LFS applied in the presence of the standard solution, 1 μ

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8-CPT and 10 μ

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CP-66713. The A-PS before and after tetanus, and after the LFS, is indicated by a, b and c, respectively, and the S-EPSP by d, e and f, respectively. B, E-S curves 20 min before the first burst stimulation (control, •), 20 min after the tetanus (LTP, ▴) and 60 min after the LFS (DP, □). The left, middle, and right graphs, respectively, show typical examples of the E-S curves before and after tetanus, and after the LFS applied in the presence of the standard solution, 1 μ

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8-CPT and 10 μ

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CP-66713. The S-EPSP and the A-PS in response to the different stimulus strengths shown in A were converted into the relationship between the S-EPSP (transverse axis) and the A-PS (vertical axis). Lines were fitted by third order polynomial curves. Subsequent LFSs in the standard solution, or in the presence of 8-CPT, returned the tetanus-induced leftward shift of the E-S curve towards the pre-tetanic control level. However, subsequent LFSs in CP-66713 induced a further shift to the left, or E-S potentiation. C, the A-PS/S-EPSP ratio measured 15-20 min after tetanus (LTP), 15-20 min after each LFS (First, Second or Third LFS) and 50-60 min after the third LFS (Final level). The LFSs were applied in the presence of the standard solution (n = 6), 1 μ

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8-CPT (n = 6) or 10 μ

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CP-66713 (n = 5). **P < 0.01, significant difference between DP in control and CP-66713-treated slices.