JZTX-IV acts on TTX-S sodium channels in DRG neurons by weakly reducing peak amplitudes and by obviously slowing inactivation kinetics. In contrast, JZTX-IV acts on TTX-R sodium channels on cardiac myocytes by obviously reducing its peak current and by weakly slowing inactivation kinetics. Additionally, JZTX-IV shifts the steady-state inactivation curve on both receptors. Even at high concentrations, JZTX-IV does not have any effect on TTX-R sodium channels on rat DRG neurons or on TTX-S sodium channels on hippocampal neurons. Effect on potassium channels At this point, the effects of JZTX-IV on potassium channels are largely unknown. JZTX-V Effect on VGSC JZTX-V has a high affinity to the resting closed state of TTX-R (Nav1.8 Nav1.9) and TTX-S (Nav1.6, Nav1.7) VGSC in DRG neurons. It modifies the sodium channel current by shifting its activation curve to a more depolarized voltage and its inactivation curve to a more hyperpolarized voltage. This means that the toxin-bound sodium channel will open at a more positive membrane potential and closes at a more negative membrane potential. Effect on potassium channels JZTX-V mainly affects the Kv4.2 potassium channel current by shifting its activation curve to a more depolarized direction and, at high concentrations, by speeding up deactivation. JZTX-IX Effect on VGSC JZTX-IX act on both TTX-R and TTX-S channels by shifting their activation state to a more depolarized voltage. In addition it captures the sodium channels at a closed state which speeds up inactivation. Effect on potassium channels JZTX-IX affects only the Kv2.1 channel by shifting its activation curve to a more depolarized voltage. JZTX-XI Effect on VGSC JZTX-XI reduces the peak sodium current amplitude of sodium channels expressed in cardiac myocytes and slows down current inactivation. JZTX-XI shows no effects on both TTX-R and TTX-S sodium currents in dorsal root ganglion neurons Effect on potassium channels JZTX-XI shifts the activation curve of Kv2.1 to a more depolarized voltage and speeds up its deactivation. JZTX-XII Effect on VGSC At this point, the effects of JZTX-XII on sodium channels are largely unknown. Effect on potassium channels JZTX-XII specifically acts on Kv4.1 potassium channels. It modulates potassium current by shifting Kv4.1 activation to more depolarized voltages and by producing a concentration-dependent slowing of activation and inactivation kinetics. JZTX-34 Effect on VGSC JZTX-34 inhibits TTX-S sodium currents, but has no effect on TTX-R sodium currents. JZTX-34 does not affect activation/inactivation kinetics nor does it affect recovery rate from inactivation. Effect