Figure 4.

Chronic inflammatory environment does not influence short-term plasticity at excitatory synapses on new and mature neurons. Whole-cell voltage-clamp recordings of paired stimulation-induced EPSCs in new and mature granule cells in hippocampal slices, perfused with aCSF containing PTX, from vehicle- or LPS-treated animals 6.5–7.5 weeks after RV-GFP labeling. Paired stimulations were delivered to lateral perforant path in the outer one-third of the molecular layer with interstimulus intervals (ISIs) of 25, 50, 100, and 200 ms. Average paired-pulse facilitation plotted at each ISI for new (A) and mature cells (B) in slices from vehicle- or LPS-treated animals. Representative EPSCs elicited with 100 ms ISI are shown in insets from vehicle-treated (A1, B1) or LPS-treated (A2, B2) animals. Twenty responses were averaged for each cell at each ISI. Comparisons using one-way ANOVA, or Student's unpaired t test at each ISI, revealed no differences between new cells or between mature cells in vehicle- and LPS-treated animals, or between new and mature cells within the same treatment group. Numbers of cells recorded were as follows: in vehicle, four GFP⁺, five GFP⁻; in LPS, five GFP⁺, five GFP⁻. Error bars indicate SEM. Calibration: A1, A2, B1, B2, 50 ms, 50 pA.