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

  1. Irene Martínez-Gallego
  2. Heriberto Coatl-Cuaya
  3. Antonio Rodriguez-Moreno  Is a corresponding author
  1. Laboratory of Cellular Neuroscience and Plasticity, Department of Physiology, Anatomy and Cell Biology, Universidad Pablo de Olavide, Spain
5 figures and 1 additional file

Figures

Figure 1 with 1 supplement
Input-specific presynaptic spike timing-dependent LTD at lateral and medial perforant pathway-dentate gyrus granule cell synapses.

(a, k) Schemes and pictures show the general set-up for the electrophysiological recordings and pairing protocol (∆t = –18ms, time between the peak of the postsynaptic spike and the onset of the …

Figure 1—figure supplement 1
GABA receptors are not required for t-LTD at LPP- or MPP-GC synapses.

(a and c) Time course of EPSP monitored in slices during baseline and after the addition of bicuculline (LPP-GC: 67 ± 6%, n=6; MPP-GC: 65 ± 8%, n=6) and SCH50911 (LPP-GC: 69±11, n=6; MPP-GC: 75 ± …

The t-LTD at lateral and medial perforant pathway-dentate gyrus granule cell synapses has distinct requirements for glutamate receptors.

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 …

Figure 3 with 1 supplement
The t-LTD at lateral and medial perforant pathway-dentate gyrus granule cell synapses requires postsynaptic calcium and eCB signalling.

(a) The induction of t-LTD at LPP-GC synapses in slices was unaffected by exposure to nimodipine (10 µM) or to heparin (5 mg/ml), but it was prevented by treatment with thapsigargin (1–10 µM) or …

Figure 3—figure supplement 1
Calcineurin is required for t-LTD induction at the LPP, but not at MPP-GC synapses.

(a) t-LTD requires postsynaptic calcineurin at LPP-GC synapses. The EPSP slopes monitored in control slices (black triangles, n=9) and in slices treated with the calcineurin blocker FK506 (1–10 µM), …

Figure 4 with 1 supplement
The t-LTD at lateral and medial perforant pathway-dentate gyrus granule cell synapses requires astrocytes and glutamate.

(a, f) Schemes showing the general experimental set-up: A, astrocyte; CA, cornus ammonis; DG, dentate gyrus; EC, entorhinal cortex; GC, granule cell; S1 and S2, stimulating electrodes; R1 and R2, …

Figure 4—figure supplement 1
Identification of astrocytes.

(a) Low magnification infrared video microscopy image showing a brain slice with a recording electrode on one astrocyte. (b) Voltage responses of typical astrocytes in the surrounding of LPP-and …

Model of presynaptic t-LTD at LPP- and MPP-GC synapses.

t-LTD is induced by a post-before-pre, single-spike pairing protocol at P13-21. Postsynaptic action potentials depolarize the postsynaptic membrane that probably permeates Ca2+ into the postsynaptic …

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