(A and B, left). Fsk (50 µM) was used to stimulate cAMP production by adenylyl cyclase (AC, green) and the cAMP analog 6-Bnz (20 µM) was used to activate protein kinase A (PKA, orange). (A and B, …
CV analysis, plotted as the ratio of CV2 versus the mean EPSC amplitude ratio, normalized to baseline. For increases or decreases in mean amplitude (vertical dotted line is the mean ratio = 1), a …
(A) Increasing stimulation frequency between 0.1 and 20 Hz reduced EPSCs due to decrease the number of active release sites, confirmed by variance/mean analysis (Foster and Regehr, 2004). (B and C) …
(A) Representative sweeps of Sr2+-evoked asynchronous EPSCs (aEPSCs) before (black) and after (orange) application of 6-Bnz (20 µM). Bullets denote detected events. (B) Distribution of aEPSC …
(A) Time course of EPSC amplitudes in response to CF stimulation at 100 Hz for 500 ms before (black) and after (orange) 6-Bnz treatment. (B) Normalized EPSC amplitudes during train stimulation …
(A and B) Time course of CF-PC EPSC amplitude (top: normalized, open circles) and PPR (bottom: open squares) during bath application of fsk (green) or 6-Bnz (orange). Insets: representative traces …
(A, left) The inactive cAMP analog 8-Br-cAMPs (8-Br, brown) was used to prevent activation of PKA and KT5720 (blue), a small molecule that occupies PKA’s ATP-binding site, was used to inhibit …
(A, left) Paired pulse depression (PPD = (1-PPR) x 100)) plotted as a function of ΔT in control (black) and KT5720-treated (blue) slices. Both data sets were fit with two-phase exponential decays. …
The PPR of CF-PC EPSCs (50 ms ISI) was highly sensitive extracellular Ca2+ reflecting changes in Pr; however, PPR was not affected by KT5720 (p=0.0001 for changes with Ca2+ and p=0.3 for PKA …
(A) Representative sweeps of Sr2+-evoked asynchronous EPSCs (aEPSCs) recorded from control (black) and KT5720-treated slices (blue). Bullets denote detected events. aEPSCs were recorded in ACSF …
(A) Representative EPSCs recorded in response to CF stimulation at 50 Hz for 500 ms in control (black) and KT5720-treated (blue) slices. To relieve receptor saturation, 3 mM KYN was added in a …
(A) Time course of CF-PC EPSC amplitude (top: normalized, circles) and paired pulse ratio (bottom: PPR with an inter-stimulus interval = 50 ms, squares) following bath application of 6-Bnz (orange) …
(A) The PPR of CF-EPSCs at multiple ISIs was unchanged in synapsin TKO mice. PPR in hets (black): 0.09 ± 0.02, 0.1 ± 0.01, 0.13 ± 0.01, 0.17 ± 0.02, 0.37 ± 0.01, 0.88 ± 0.02, 0.97 ± 0.01 and in TKOs …
(A) Cartoon and schematic of short-term plasticity model showing how synapsin controls the number of release-competent sites per active zone. Synaptic vesicles (gray) are bound by synapsin (green) …
(A) Unitary responses following five parallel fiber stimuli (S1– S5) delivered at 50 Hz. (B left) Individual parallel fibers were identified by a sharp threshold between failures and successes (S1 …
(A) Superimposed CF-MLI spillover EPSCs before and after bath application of γ-DGG (300 µM) or NBQX (200 nM) in control slices and after incubation with KT5720 (1 µM) or 8-Br-cAMPs (50 µM) for …
Reagent type (species) or resource | Designation | Source or reference | Identifiers | Additional information |
---|---|---|---|---|
Gnetic reagent (M. musculus) | wildtype; WT; control | Jackson Laboratories | RRID:IMSR_JAX:000664 | |
Genetic reagent (M. musculus) | synapsin triple knockout, TKO | MMRC | RRID:MMRRC_041434-JAX | |
Genetic reagent (M. musculus) | synapsin triple het; het | this paper | WT x TKO cross | |
Peptide, recombinant protein | PKA inhibitory fragment (6-22) amide, PKi | Tocris | Cat#: 1904; CAS: 121932-06-7 | |
Chemical compound, drug | 6-Bnz-cAMP; 6-Bnz | BioLog via Axxora | Cat#: B009; CAS: 30275-80-0 | |
Chemical compound, drug | 8-Br-cAMPs; 8-Br | Santa Cruz | Cat#: B009; CAS: 30275-80-0 | |
Chemical compound, drug | forskolin; fsk | HelloBio | Cat#: HB1348; CAS: 66575-29-9 | |
Chemical compound, drug | KT5720; KT | Tocris | Cat#: 1288; CAS: 108068-98-0 | |
Chemical compound, drug | kynurenic acid, KYN | Abcam | Cat#: ab120256; CAS: 494-27-3 | |
Chemical compound, drug | NBQX | Abcam | Cat#: ab120045; CAS: 118876-58-7 | |
Chemical compound, drug | Picrotoxin | Abcam | Cat#: ab120315; CAS: 124-87-8 | |
Chemical compound, drug | QX-314 | Abcam | Cat#: ab120118; CAS: 5369-03-9 | |
Software, algorithm | Axograph X, version 1.5.4 | AxoGraph Scientific | https://axograph.com/ | |
Software, algorithm | Mathematica 11 | Wolfram | http://www.wolfram.com/mathematica/ | |
Software, algorithm | pCLAMP 10 | Molecular Devices | https://www.moleculardevices.com/ | |
Software, algorithm | Prism | Graphpad | https://www.graphpad.com/ |
Symbol | Definition | |
---|---|---|
CaXF0 | Concentration of Ca2+-bound site XF | 0 |
CaXD0 | Concentration of Ca2+-bound site XD | 0 |
ΔF | Incremental increase in CaXF after a stimulus | 5 |
ΔD | Incremental increase in CaXD after a stimulus | 0.001 |
τF | Decay time constant of CaXF after an action potential | 0.1 sec−1 |
τD | Decay time constant of CaXD after an action potential | 0.05 s |
KF | Affinity of CaXF for site | 2 |
KD | Affinity of CaXD for site | 2 |
k0 | Baseline rate of recovery from recovery state | 0.7 sec−1 |
kmax | Maximal rate of recovery from refractory state | 20 sec−1 |
D | Fraction of sites that are release-ready | 1 |
F | Facilitation probability | (0–1) |
NT | Total number of sites | (1 - 10) |
Pocc | Probability of site occupancy | (0–1) |
RRP | Readily releasable pool | NT * Pocc |
Psucc | Probability that a competent vesicle will release | F * D |