Fig. 1: Astrocytic P2Y1R overexpression leads to decreased susceptibility to drug-induced seizures, increased abnormal spikes, and increased bidirectional communication between neurons and astrocytes.

A Representative EEG traces. A bipolar electrode was placed in the left hippocampus. The AstroP2Y1OE mice showed more spikes. Control, N = 5 mice; AstroP2Y1OE, N = 5 mice (two-sided two-sample t-test). Box-plot elements are defined in the following way: center line, median; box limits, upper and lower quartiles; whiskers, 1.5× interquartile range; square, mean. B Mice were administrated pilocarpine (100 mg/kg) every 20 min to reach severe seizure (Racine stage 5). The bar graph indicates the cumulative dose of pilocarpine needed to induce seizure at Racine stage 5. Control, N = 8 mice; AstroP2Y1OE, N = 12 mice (two-sided Mann–Whitney U test). Box-plot elements are defined in the following way: center line, median; box limits, upper and lower quartiles; whiskers, 1.5× interquartile range; square, mean. C Left, Schematic diagram for the AAV-mediated expression of GCaMP6f in astrocytes and jRGECO1a in neurons. The schematic diagram in (C) was created with BioRender.com released under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International license. Right, Representative images of dual-color Ca²⁺ imaging of astrocytes (GcaMP6f) and neurons (jRGECO1a) in the stratum radiatum of the hippocampal CA1 region in AstroP2Y1OE mice. Time-stacked images were obtained from eight frames, as indicated at the top of the images (AstroP2Y1OE). Images were taken every 300 ms. The Schaffer collaterals were stimulated by an electrode (0.06 mA, 40 Hz, 2.5 s) between 101 and 108 frames. Yellow rectangles in the left panel indicate the ROIs. The same experiments were conducted using 9 slices, 4 mice for control and 6 slices, 4 mice for AstroP2Y1OE. D Sample traces of EFS-evoked Ca²⁺ signals. Both neuronal and astrocytic Ca²⁺ signals were enhanced in response to the EFS in AstroP2Y1OE mice. EFS was delivered at the duration indicated by yellow boxes. E Summary of EFS-evoked Ca²⁺ signals for neurons. Neuronal Ca²⁺ responses were enhanced in AstroP2Y1OE mice (red circles) compared with the control (black circles). The left panel shows the data for Ca²⁺ responses as the area under the curve. The right panel shows the data for peak Ca²⁺ responses. Control, n = 36 ROIs from 9 slices, 4 mice; AstroP2Y1OE, n = 24 ROIs from 6 slices, 4 mice (two-way repeated measures ANOVA and Tukey’s test for the left panel; two-sided two-sample t-test for the right panel). For the left panel, data are presented as mean ± s.e.m. For the right panel, box-plot elements are defined in the following way: center line, median; box limits, upper and lower quartiles; whiskers, 1.5× interquartile range; square, mean. F Summary of EFS-evoked Ca²⁺ signals for astrocytes. ROIs were set at the same regions of FOVs of GCaMP6f images so that n numbers are the same as those in (E). The left panel shows the data for Ca²⁺ signals as the area under the curve. The right panel shows the data for peak Ca²⁺ signals. Data are presented as mean ± s.e.m. Black circles, control; red circles, AstroP2Y1OE. Source data are provided as a Source Data file.