Journal: The Journal of Neuroscience

Article Title: Astrocyte Signaling Gates Long-Term Depression at Corticostriatal Synapses of the Direct Pathway

doi: 10.1523/JNEUROSCI.2369-19.2020

Figure Lengend Snippet: Adenosine and glutamate gate HFS-LTD at cortico-dSPN synapses. A, top left, Experimental configuration in horizontal brain slices of C57BL/6J mice. Bottom left, Confocal laser scanning microscope images of triple immunofluorescence for biotin, A2AR, and SP in patch-recorded neurons. Right, Scheme of HFS protocol. B, top left, Scheme showing glutamatergic cortical inputs to dSPNs, which are recruited following cortical electrical stimulation. Top right, Averaged recordings (10 EPSPs) before (black line) and after (blue line) HFS. Bottom left, Relative EPSP amplitude before and after HFS (vertical blue bar, as in other panels and figures) of cortical connections to dSPN in DLS in control conditions (white, n = 6, 6 mice), in the presence of the mGluR5 antagonist MPEP (yellow, n = 7, 6 mice), and in the presence of the GABABR antagonist, CGP55845 (green, n = 6, 5 mice). Bottom right, Mean normalized EPSP amplitudes before (pre) and 25–30 min after HFS (post; as in other figures) in control (white, n = 6, 6 mice, t = 9.3, df = 5, ***p = 0.0002, paired t test), MPEP (yellow, n = 7, 6 mice, t = 1, df = 6, p = 0.3, paired t test), and CGP55845 (green, n = 6, 5 mice, t = 5, df = 5, **p = 0.0038, paired t test). C, top, Averaged recordings (10 EPSCs) before (black) and after (blue) HFS. Bottom left, Relative EPSP amplitude before and after HFS in control conditions (black, n = 8, 7 mice), in the presence of MPEP (yellow, n = 5, 3 mice), the A1R antagonist DPCPX (brown, n = 8, 7 mice), and the eCB CB1R antagonist AM-251 (purple, n = 5, 3 mice). Bottom right, Mean EPSC amplitudes before and after HFS in control (black, n = 8, 7 mice, t = 4.9, df = 7, **p = 0.0018, paired t test), MPEP (yellow, n = 5, 3 mice, t = 0.4, df = 4, p = 0.7, paired t test), DPCPX (brown, n = 8, 7 mice, t = 2.2, df = 7, p = 0.06, paired t test), or AM-251 (purple, n = 5, 3 mice, t = 2.8, df = 4, *p = 0.049, paired t test). D, left, Mean CV−2 before and after HFS for the EPSP group in control conditions (white, n = 6, 6 mice, t = 2.6, df = 5, *p = 0.048, paired t test) or in the presence of MPEP (yellow, n = 7, 6 mice, W = 10, p = 0.47, Wilcoxon matched-pairs signed-rank test) or CGP (green, n = 6, 5 mice, t = 3.2, df = 5, *p = 0.024, paired t test). Right, Mean CV−2 before and after HFS delivery for the EPSC group in control conditions (black, n = 8, 7 mice, t = 2.9, df = 7, *p = 0.024, paired t test) or in the presence of MPEP (yellow, n = 5, 3 mice, W = −1, p > 0.9999, Wilcoxon matched-pairs signed-rank test), DPCPX (brown, n = 8, 7 mice, t = 1.4, df = 7, p = 0.2, paired t test), or AM-251 (purple, n = 5, 3 mice, t = 12, df = 4, p = 0.3, paired t test). Bar diagrams summarize the ratio of the SD and the mean EPSP or EPSC amplitude of the last 7 min before compared with the last 7 min after HFS delivery (as in other figures). Data are presented as mean ± SEM.

Article Snippet: However, we found that HFS-LTD at cortico-dSPN synapses was unaffected by the GABA B R antagonist CGP55845 (10 μ m ; B ), and it was accompanied by a change in CV −2 ( D ), suggesting that GABA B R activation was not involved in HFS-induced LTD.

Techniques: Laser-Scanning Microscopy, Immunofluorescence, Control