Journal: eLife

Article Title: Astrocytes mediate two forms of spike timing-dependent depression at entorhinal cortex-hippocampal synapses

doi: 10.7554/eLife.98031

Figure Lengend Snippet: The t-LTD at LPP-GC synapses does not require NMDAR but requires mGluR5 .( a ) The addition of D-AP5 (50 μM) or MK-801 (500 μM) to the superfusion fluid does not prevent the induction of t-LTD at LPP-GC synapses. The EPSP slopes shown are from D-AP5-treated (red triangles, n=8), MK-801-treated (grey triangles, n=6) and untreated cells (black triangles, n=8). The traces show EPSPs before (1) and 30 min after (2) pairing. ( b ) Summary of the results. ( c ) The EPSP slopes are shown from control slices (black triangles, n=9), and slices treated with the mGluR antagonist LY341495 (100 µM, red squares, n=8), the mGluR1 antagonist LY367385 (100 µM, grey triangles, n=6) or the mGluR5 antagonist MPEP (20 µM, blue squares, n=8). The traces show the EPSPs before (1) and 30 min after (2) pairing. ( d ) Summary of the results. ( e ) The t-LTD at MPP-GC synapses requires NMDARs containing GluN2A subunits and mGluR1 . The addition of D-AP5 (50 µM) or MK-801 (500 µM) to the superfusion fluid prevented t-LTD induction at MPP-GC synapses, whereas postsynaptic loading of MK-801 (500 µM) did not block t-LTD induction. The EPSP slopes are shown from D-AP5 (open red squares, n=10) or MK-801 treated cells (bath, open grey squares, n=6; loaded into postsynaptic cell, open blue triangles, n=9), and untreated cells (open black triangles, n=8). The traces show the EPSPs before (1) and 30 min after (2) pairing. ( f ) Summary of the results. ( g ) The NMDARs involved in t-LTD at MPP-GC synapses contain GluN2A subunits . The t-LTD at MPP-GC synapses was completely blocked in slices exposed to Zn 2+ (300 nM), while it remained unaffected in slices treated with Ro 25–6981 (0.5 µM), ifenprodil (3 µM) or PPDA. The EPSP slopes shown are from control slices (open black triangles, n=9) and slices treated with Zn 2+ (open red squares, n=7), Ro-25–6981 (open grey triangles, n=6), ifenprodil (open blue triangles, n=6) or PPDA (open pink triangles, n=6). The traces show the EPSPs before (1) and 30 min after (2) pairing. ( h ) Summary of the results. ( i ) The t-LTD at MPP-GC synapses requires mGluR1 . The EPSP slopes shown are from control slices (open black triangles, n=9), or slices treated with LY341495 (100 µM, open red squares, n=10), LY367385 (100 µM, open grey squares, n=7) or MPEP (20 µM, open blue triangles, n=6). The traces show the EPSPs before (1) and 30 min after (2) pairing. ( j ) Summary of the results. The error bars indicate the S.E.M. *p<0.05, ** p<0.01, ***p<0.001, One-way ANOVA + Holm–Sidak test. Figure 2—source data 1. Individual values included in the histograms of .

Article Snippet: The following agents were purchased from: Sigma-Aldrich - BAPTA, Zinc chloride, and the compounds used to prepare the ACSF and current clamp internal solutions; and Tocris Bioscience - MK-801 maleate, D-AP5, TTX, PPDA, Ro 25–6981 maleate, L-glutamic acid, MPEP, LY367385, LY341495, AM251, Orlistat (THL), Evans blue, WIN 55,212–2, FK506, Nimodipine, Thapsigargin, Ifenprodil, ruthenium red, bicuculline, SCH50911 and NBQX.

Techniques: Control, Blocking Assay