Scope software

After the MWM test, mice were prepared for electrophysiological recording. Long-term potentiation (LTP) in the perforant pathway (PP) synapses of dentate gyrus (DG) was recorded to assess synaptic plasticity. LTP was viewed as a physical basis for memory encoding in the hippocampus 28 (link). After anesthetization with 5% urethane (30 ml/kg, ip), the mice were placed in a small-rodent stereotaxic frame (Narishige, Japan). After exposing the skull surface, a small hole was made in the left dorsal skull using a dental drill, and a bipolar stimulation electrode was slowly lowered into the PP. Subsequently, a monopolar stainless steel electrode was lowered into the DG. The optimal coordinates of electrodes' locations were confirmed based on the previously reported data 29 (link). Afterward, a stable normalized baseline was recorded for 20 min. Then theta burst stimulation (TBS) was used to induce LTP. After TBS, field excitatory postsynaptic potentials (fEPSP) were recorded every 60 s for 60 min (Scope Software, Powlab, AD Instruments, Australia). The mean fEPSP slope to reflect synaptic efficacy was normalized to the baseline.

All fPSPs were stored and analyzed using Scope software (v. 3.6.5, AD Instruments). In agreement with prior work [7 (link), 8 (link)], fPSPs in A1 elicited by MGN stimulation consisted of two negative-going peaks (see Figure 1(b)). The amplitude of each peak was computed offline by calculating the voltage difference between the activity measured immediately prior to the stimulus artifact and that of the maximum peak negativity. Amplitude values were averaged over 10-minute intervals and normalized by dividing them by the average baseline amplitude of each animal.
For paired-pulse responses, fPSPs were averaged for each ISI, before and after LTP induction (pre-LTP and post-LTP, resp.). A paired-pulse ratio (PPR) was calculated for each rat at each ISI by dividing the peak amplitude (computed as described above) of the second fPSP by that of the first fPSP (note that PPRs were calculated only for the first of the two negative peaks of the fPSP). A PPR value of greater than 1.0 reflects PPF, whereas a PPR value of less than 1.0 reflects PPD of synaptic transmission.
All data are expressed as mean ± standard error of the mean (SEM). Statistical comparisons were made using mixed-model analyses of variance (ANOVA) and, where statistically appropriate, pairwise comparisons using the SPSS software package (version 21.0, SPSS Inc., IL, USA).

Data are expressed as mean ± standard error of the mean (SEM). The fPSP amplitude was computed offline by Scope software (v.4.1.1, AD Instruments). Values for each rat were averaged over 10 min intervals and these averages were normalized by dividing them by the averaged baseline (pre-TBS) amplitude of that animal. Data were statistically evaluated by repeated measures analysis of variance (ANOVA) and, if statistically appropriate, simple effects tests using the CLR ANOVA software package (v.1.1, Clear Lake Research Inc., Houston, TX). The level of significance for statistical analyses was set at P < 0.05. Note that the results of all statistical analyses are reported in the appropriate figure captions.