Figure 5

Paclitaxel increases the release of glutamate from presynaptic terminals and activities of glutamate receptors at postsynaptic neurons in the spinal dorsal horn through activation of TLR4. Raw data show that bath-perfusion of paclitaxel significantly increased both the frequency and amplitudes of mEPSCs in a dose-dependent manner in rats (A) and (B), but these effects were abolished in rats in the presence of the TLR4 inhibitor (LPS-RS) (C), and in TLR4 knockout mice (D). Bar graphs show the mean (+ S.E.) frequency and amplitude of mEPSCs before, during, and after washout of paclitaxel (1 ng/ml) in rats (E) and wild-type mice (G), as well as in the presence of LPS-RS in rats (H) and wild-type mice (I). The mean (+ S.E.) frequency and amplitude of mEPSCs before, during, and after washout of paclitaxel at 0.1 ng/ml, 1 ng/ml, and 10 ng/ml in rats are presented in (F). The mean (+ S.E.) frequency and amplitude of mEPSCs before and during paclitaxel (1 ng/ml) perfusion in TLR4 knockout mice are shown in (J). Number of neurons included in each group for the analysis is shown in each bar. **P < 0.01; ***P < 0.001; NS, no statistical significance.