Figure 5. CB₁R Signaling Mediates the Expression of LTD Triggered by CP-AMPARs at Glutamatergic Synapses onto PV(+)-INs.

All scale bars: 50 pA/50 ms.

(A) Schematic depicting retrograde eCB signaling at glutamatergic synapses onto PV-INs.

(B) Representative DSE experiment performed in triplicate for each PV(+)-IN with EPSC sampling rate increased to 0.2 Hz.

(C) Top: representative traces of EPSCs obtained pre- and post-DSE in ACSF. Bottom: time course summary of normalized EPSCs obtained from PV(+)-INs during DSE experiment performed in ACSF.

(D) Top: representative traces of EPSCs obtained pre- and post-DSE in AM251 (black circle) and EGTA-containing internal solution (pink open circle). Bottom: time course summary of normalized EPSCs obtained from PV(+)-INs during DSE experiment performed in AM251 (black circles) and EGTA (pink open circles).

(E) Quantification of average EPSC amplitude post-DSE following each pharmacological manipulation.

(F) Representative traces and normalized time course summary of EPSCs obtained from PV(+)-INs pre- and post-LFS in AM251 (top, pink-filled circles) and WIN 55–12 (bottom, pink open circles).

(G) Representative traces and normalized time course summary of EPSCs obtained from PV(+)-INs at baseline, following WIN 55–212 application and in AM251.

(H) Quantification of EPSCs during WIN 55–212 and AM251 bath application.

(I) Representative traces and normalized time course summary of EPSCs obtained from PV(+)-INs pre- and post-LFS in URB597 (pink-filled circles) and DO34 (open circles).

(J) Average EPSC amplitude post-LFS following each pharmacological treatment.

(K) Normalized time-course summary of EPSCs obtained from PV(+)-INs during WIN 55–212 superfusion in slices incubated in URB497. Gray-shaded summary depicts control WIN 55–212 experiments performed in (G).

(L) Time course summary of normalized EPSCs obtained from PV(+)-INs during DSE experiments repeated in ACSF- and in URB597-incubated slices. Error bars indicate SEM. *p < 0.05.