1. Fig. 4 SDPS alters parvalbumin-positive interneuron properties and decreases inhibitory transmission in the hippocampus.
SDPS alters parvalbumin-positive interneuron properties and decreases inhibitory transmission in the hippocampus. (A and B) In the hippocampal CA1 stratum pyramidale, SDPS did not affect the total number of parvalbumin-positive interneurons having a PNN coat (PNN+ PV+) (A) but did cause a moderate (7.8 ± 1.0%) increase in the intensity of parvalbumin immunoreactivity in SDPS versus control animals (B). (C and D) Representative examples of labeling of hippocampal CA1 parvalbumin-positive interneurons in SDPS and control animals (high intensity, white arrowheads; intermediate-low intensity, yellow arrowheads) (C). (D) Within double-immunopositive (PNN+ PV+) interneurons, SDPS decreased the fraction of intermediate-low parvalbumin–expressing cells (control, 22.1%; SDPS, 11.8%) and increased the fraction of high parvalbumin–expressing interneurons (control, 26.2%; SDPS, 44.1%) (D, left). No difference in the fraction of low or intermediate-high parvalbumin–expressing interneurons was observed. No intensity shift was observed in PNN-free parvalbumin-positive (PNN− PV+) interneurons (D, right). (E and F) Quantification of bassoon-positive (Bs+) puncta showed no effect of SDPS on perisomatic excitatory input onto PNN+ PV+ interneurons [representative example (E)]. In control and SDPS animals alike, PNN− PV+ interneurons showed increased density of Bs+ puncta versus PNN+ PV+ cells (F). AU, arbitrary units. (G) Example traces of whole-cell patch-clamp recordings (5 s) of hippocampal CA1 pyramidal neurons. (H) SDPS reduced sIPSC frequency (left) while leaving amplitude unaffected (right). Scale bars, 50 μm (C) or 20 μm (E); str.or, stratum oriens; str.pyr, stratum pyramidale; str.rad, stratum radiatum; n = number of animals; N = number of sections/slices; Mann-Whitney (A and F); paired t test (B and F); one-way ANOVA (D and F); *P < 0.05 and **P < 0.01 (see table S2).
Danai Riga et al., Sci Transl Med 2017;9:eaai8753
Published by AAAS