Fig. 5
- ID
- ZDB-FIG-221214-16
- Publication
- Zaupa et al., 2021 - Trans-inhibition of axon terminals underlies competition in the habenulo-interpeduncular pathway
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Calcium inhibition occurs via presynaptic GABAB receptors
(A-B) Representative ΔF/F traces in terminals at dIPN (top) and raphe (bottom) after application of (A) 1 μM cgp55845 or (B) 3 μM tetrodotoxin (TTX) + 2 μM baclofen. Time of drug application indicated (vertical lines). (A’) Average peak amplitude before and after cgp55845 application in terminals at the dIPN (−0.16 ± 0.03 vs −0.04 ± 0.01) and raphe (0.22 ± 0.09 vs. 0.26 ± 0.13) during inhibition (top) and burst (bottom). n = 6 explants, 50 events. Red asterisks indicate attenuated calcium inhibition at the dIPN after cgp55845 application. (B’) Paired plots comparing average inhibition amplitude in control conditions (−0.22 ± 0.07) to the average baseline decrease after baclofen application (−0.24 ± 0.08). n = 7 explants, 46 events. Note abrupt decrease (red arrowhead) in baseline at the dIPN following baclofen. (C) ΔF/F traces of IPN (top) aligned with simultaneous whole-cell patch-clamp recording trace (middle) upon baclofen perfusion. Time of baclofen application indicated (black bar). Magnified traces of synaptic activity before (left) and after (right) baclofen (bottom panels). (C’) Paired plot of synaptic activity frequency before (4.29 ± 1.05 Hz) and after (0.47 ± 0.15 Hz) baclofen. n = 6 explants. Mean ± SD indicated in (A’, B’, C’). (D,E) Dorsal (left) and sagittal (right) views of gabbr1a (D) and gabbr1b (E) expression at 6 dpf. dHb nuclei (red arrowheads) and absence of expression at IPN (white arrowhead) (D). Wilcoxon signed-rank test. * p< 0.05. Scale bars: 50 μm. |