2+ How does presynaptic Ca influx (i.e. current) relate to the length of time that a presynaptic neuron is depolarized above its threshold? slower frequency of action potentials always leads to less Ca2+ influx per action potential higher frequency of action potentials always leads to less Ca2+ influx per action potential longer action potentials (i.e. duration) lead to increased Ca2+ current into the neuron there is no relationship between Ca2+ influx and action potentials higher amplitude action potentials lead to an increase in Ca2+ current into the neuron.

1. How does presynaptic Ca
2+
influx (i.e. current) relate to the length of time that a presynaptic
neuron is depolarized above its threshold?
slower frequency of action potentials always leads to less Ca2+ influx per action potential
higher frequency of action potentials always leads to less Ca2+ influx per action potential
longer action potentials (i.e. duration) lead to increased Ca2+ current into the neuron
there is no relationship between Ca2+ influx and action potentials
higher amplitude action potentials lead to an increase in Ca2+ current into the neuron