Skip to main content
Fig. 5 | The Journal of Physiological Sciences

Fig. 5

From: The mechanism of increased postnatal heart rate and sinoatrial node pacemaker activity in mice

Fig. 5

I f in isolated SAN cells from neonatal and adult mice. a Whole-cell current of neonatal (left) and adult (right) SAN cell in external solution containing 1.8 mM Ni2+ and 1 mM Ba2+. The holding potential (V h) was −50 mV and 2-s depolarizing pulses were applied in 10-mV increments. V t, test potential. b Current–voltage relationships for the initial current (squares) and the current at the end of the 2-s pulses (circles). Open and filled symbols indicate neonatal and adult mice, respectively. Data are means of six and five cells for neonatal and adult SAN cells, respectively. c Voltage-dependent activation of I f. The tail current amplitude was normalized in reference to that of the maximal amplitude and plotted against the membrane potential. The smooth curves were drawn by the least squares fit with the Boltzmann equation. Data are mean ± SEM

Back to article page