Fig. 4

Fig. 4 Diverse cellular properties of the intracardiac SAP neurons.

a Ex-vivo setup of an isolated intact adult zebrafish heart from the Tg(elav3:EGFP) line allows whole-cell patch-clamp recordings of SAP neurons. The dotted line indicates a recorded neuron. b The SAP neurons display distinct firing pattern properties and responses to hyperpolarizing and depolarizing current step injections. The depolarization current step injections from rheobase increased by 10% of rheobase. c Differential representation of the neuronal types in the SAP region of the adult zebrafish heart. d Normalized mean values (min to max) of the electrical properties observed for the SAP neuron types that are detailed described in Supplementary Fig. 4. Every column indicates a neuron and every row represents an electrical property. e Sample traces showing the variable spontaneous activity of the different SAP neuron firing classes recorded in the adult zebrafish heart. Analysis of the presence (proportion) and frequency of spontaneous action potentials between the SAP neurons. f Representative voltage-clamp traces show the spontaneous excitatory synaptic currents (EPSCs) between the different SAP neurons. Analysis of the detected EPSC frequency and amplitude. g The principal component analysis (PCA) plot depicts three clusters of SAP neurons based on physiological properties (dataset presented in d and e). Cells and data are colored by the assigned cell type (as in b). AHP, after-hyperpolarization potential; CDF, cumulative distribution frequency; DIC, Differential interference contrast; EPSC, excitatory postsynaptic current; GFP, green fluorescent protein; Rinput, input resistance; RMP, resting membrane potential; SAP, sinoatrial plexus. Data are presented as mean ± SEM and as violin plots. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001; ns, not significant. For detailed statistics, see Supplementary Table 1. Source data are provided as a Source Data file.