Fig. 4.

Astrocytic modulation of glutamatergic synaptic transmission on adult-born neurons. a, b Representative experiment showing whole-cell recordings obtained from a retrovirally labeled 4-week-old neuron. Paired pulses (50 ms apart) were delivered to the perforant path at low frequency (0.07 Hz) in the presence of picrotoxin (100 µM). a Postsynaptic current traces obtained before (Baseline, at 4 min), during (DHK, at 17 min) and after (Wash, at 32 min) application of DHK (300 µM). Each trace is an average of 12 sweeps. Scale bars 100 pA, 20 ms. b Peak amplitude of the first EPSC and paired-pulse ratio (PPR) measured in the same experiment shown in a. Dotted lines denote mean baseline values. c Mean values obtained from nine experiments showing normalized peak EPSCs and PPR. Data points were binned in 1-min intervals. Dots indicate mean ± SEM values. DHK reduced peak EPSC amplitude (0.64 ± 0.06, p < 0.01, Wilcoxon test for paired samples). PPR increase was consistent but not significant (1.33 ± 0.26, p = 0.16, Wilcoxon test for paired samples). Gray bars denote DHK (300 µM) application