Fig. 2
ATX inhibition rescues neuronal hyperexcitability and PPI deficits in PRG-1-deficient animals. a Miniature excitatory postsynaptic currents (mEPSCs) in CA1 pyramidal neurons of wild-type (WT) slices were not affected by ATX inhibition with 1 µM PF8380. However, in PRG-1-/- slices, which display higher mEPSC frequency, ATX inhibition significantly diminished mEPSC frequency to WT levels. In line, astrocyte-specific ATX deletion significantly decreased mEPSC frequency in PRG-1-/- animals to WT levels. Amplitudes (see Fig. S2C) were not affected supporting a presynaptic effect (n = 13 WT neurons, 8 PF8380-treated WT neurons, 10 PRG-1-/- neurons, 10 PF8380-treated PRG-1-/- neurons and 10 PRG-1-/-/ATXfl/fl:GFAP-Cre+ neurons; one-way ANOVA with Bonferroni post hoc). b Original traces showing spontaneous excitatory postsynaptic currents (spEPSCs) of neurons under different conditions. c Although ATX inhibition via PF8380 application did not alter spontaneous excitatory (spEPSCs) frequency in WT slices, higher spontaneous frequency observed in PRG-1-/- neurons was significantly decreased to WT levels. Similarly, genetic deletion of ATX in astrocytes decreased spontaneous excitatory frequency in PRG-1-/- neurons to WT levels, whereas amplitudes were not affected (see Fig. S2D) (n = 11 WT neurons, 12 PF8380-treated WT neurons, 19 PRG-1-/- neurons, 17 PF8380-treated PRG-1-/- neurons and 18 PRG-1-/-/ATXfl/fl:GFAP-Cre+ neurons; Kruskal–Wallis test with Dunn’s multiple comparisons post hoc test). d Paired-pulse ratio (PPR) in PRG-1-/- animals was significantly increased after ATX inhibition. e ATX inhibition by PF8380 decreased the first eEPSC(1) in PRG-1-/- animals. f Coherence analysis of simultaneous recordings of field potentials in layer II/III of the medial entorhinal cortex (MEC) and the hippocampal CA1 in freely moving mice revealed significantly higher coherence in the gamma range (30–70 Hz, dashed box) in PRG-1-/- mice. Interestingly, LPA reduction by application of the ATX inhibitor PF8380 reduced this coherence in PRG-1-/- mice to WT level (see also Fig. S3A, D-F). g Quantitative analysis revealed significantly increased mean gamma coherence in PRG-1-/- mice, which was reduced to WT levels upon PF8380-treatment (n = 15 WT mice, 12 untreated PRG1-/- and 7 PF8380-treated PRG1-/- mice; one-way ANOVA with Bonferroni post hoc; see also Fig S3B). h In order to assess the efficiency of ATX inhibition by PF8380, LPA levels were measured in the CSF after PF8380 application (30 mg/kg body weight). Here, we found a clear decrease in the main LPA species (LPA 16:0, 18:1, 18:2 and 20:4; n = 6 for all groups; one tailed, Mann–Whitney test; see also Fig. S2C). i Pre-pulse inhibition (PPI) at all tested loudness levels was significantly decreased in a mouse line expressing a monoallelic human PRG-1 single-nucleotide polymorphism (SNP). However, PF8380 application rescued decreased PPI to WT levels (n = 9 WT mice, 15 untreated PRG1+/R346T and 15 PF8380-treated PRG1+/R346T mice; one-way ANOVA with Bonferroni post hoc; see also Fig. S3G-I). Bars represent mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001
