Figure 1: ZD7288 enhances LFS-induced LTD in early postnatal rats. (a) The time course of the excitatory postsynaptic field potential (fEPSP) amplitude following stimulation of the medial perforant path (MPP) in early postnatal rats (P9–15) displays LTD (closed symbols) following low-frequency stimulation (LFS, indicated by an open bar). Time-control experiments without LFS (open symbols) confirmed stable recording conditions. Representative fEPSPs were taken at the beginning (indicated by “1”) and at the end (indicated by “2”) of the experiment. (b) The time course of the fEPSP amplitude following ZD7288 treatment (starting 10 min prior to LFS, indicated by a closed bar) shows an enhanced depression in LFS-treated slices (closed symbols). Non-LFS-treated time-control experiments (open symbols) showed a synaptic depression after ZD7288 application. Note the large difference of fEPSP amplitudes at the end of the experiment which was more pronounced than that without ZD7288 application in (a). (c) Comparing the fEPSP amplitude time course following ZD7288 treatment (starting after LFS, indicated by a gray bar) between LFS-treated (gray symbols) and non-LFS-treated time-control experiments (open symbols) reveals a synaptic depression which was similar to that in non-ZD7288 conditions shown in (a). (d) Normalized time courses of fEPSP amplitudes in three different conditions: without ZD7288 (open symbols), ZD7288 before LFS (closed symbols), and ZD7288 after LFS (gray symbols). Note that similar levels of LFS-induced STD and LTD were obtained in both slices without ZD7288 and slices with ZD7288 after LFS. (e) The bar graph summarizes the STD and LTD levels of three different conditions. The number of slices is given in parentheses (number of LFS-treated slices/number of non-LFS-treated slices). (f) The bar graph summarizes the paired-pulse ratio of all experimental groups recorded at the beginning of each experiment, that is, before ZD7288 and/or LFS were applied to the slices. Note that the PPR was similar in all groups. All data are mean ± SEM.