Dual-Cell Patch-Clamp Recording Revealed a Mechanism for a Ribbon Synapse to Process Both Digital and Analog Inputs and Outputs
| Autor: | Fan Gao, Samuel M. Wu, Ji-Jie Pang |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
ganglion cell
retina Materials science genetic structures Chemical synapse dual-cell patch-clamp Neurosciences. Biological psychiatry. Neuropsychiatry Ribbon synapse Retinal ganglion Cellular and Molecular Neuroscience Postsynaptic potential medicine Graded potential light response Original Research Depolarization photoreceptor bipolar cell medicine.anatomical_structure Excitatory postsynaptic potential Biophysics glutamate synapse sense organs Glutamatergic synapse Neuroscience RC321-571 |
| Zdroj: | Frontiers in Cellular Neuroscience, Vol 15 (2021) Frontiers in Cellular Neuroscience |
| ISSN: | 1662-5102 |
| Popis: | A chemical synapse is either an action potential (AP) synapse or a graded potential (GP) synapse but not both. This study investigated how signals passed the glutamatergic synapse between the rod photoreceptor and its postsynaptic hyperpolarizing bipolar cells (HBCs) and light responses of retinal neurons with dual-cell and single-cell patch-clamp recording techniques. The results showed that scotopic lights evoked GPs in rods, whose depolarizing Phase 3 associated with the light offset also evoked APs of a duration of 241.8 ms and a slope of 4.5 mV/ms. The depolarization speed of Phase 3 (Speed) was 0.0001–0.0111 mV/ms and 0.103–0.469 mV/ms for rods and cones, respectively. On pairs of recorded rods and HBCs, only the depolarizing limbs of square waves applied to rods evoked clear currents in HBCs which reversed at −6.1 mV, indicating cation currents. We further used stimuli that simulated the rod light response to stimulate rods and recorded the rod-evoked excitatory current (rdEPSC) in HBCs. The normalized amplitude (R/Rmax), delay, and rising slope of rdEPSCs were differentially exponentially correlated with the Speed (allp< 0.001). For the Speed < 0.1 mV/ms, R/Rmaxgrew while the delay and duration reduced slowly; for the Speed between 0.1 and 0.4 mV/ms, R/Rmaxgrew fast while the delay and duration dramatically decreased; for the Speed > 0.4 mV/ms, R/Rmaxreached the plateau, while the delay and duration approached the minimum, resembling digital signals. The rdEPSC peak was left-shifted and much faster than currents in rods. The scotopic-light-offset-associated major and minor cation currents in retinal ganglion cells (RGCs), the gigantic excitatory transient currents (GTECs) in HBCs, and APs and Phase 3 in rods showed comparable light-intensity-related locations. The data demonstrate that the rod-HBC synapse is a perfect synapse that can differentially decode and code analog and digital signals to process enormously varied rod and coupled-cone inputs. |
| Databáze: | OpenAIRE |
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