An action potential is triggered when a sufficiently strong neural signal reaches the trigger zone of a neuron, which is the axon hillock or the initial segment of the axon.
The trigger zone contains a dense concentration of voltage-gated sodium-ion pores, which open and allow sodium ions into the neuron when the membrane voltage there rises from about -70mV resting potential to a trigger threshold of about -55mV as a result of a summing of inputs to the neuron.
The resulting inrush of sodium ions through the ion pores is the beginning of the action potential.
A temporary accumulation of sodium ions at the axon hillock which yields a voltage sufficient to open voltage-gated ion pores on the axon is what triggers an action potential.
A sudden increase in membrane potential, typically from a resting membrane potential of around -70mV to a threshold potential of around -55mV, triggers the opening of voltage-gated sodium channels leading to depolarization and initiation of an action potential.
neurotransmitters from the synaptic vesicles into the synapse. These neurotransmitters then bind to receptor proteins on the adjacent neuron, initiating a new action potential in the postsynaptic neuron.
Following a threshold potential, voltage-gated sodium channels open, allowing sodium ions to rush into the cell, depolarizing the membrane. This triggers an action potential that spreads down the length of the neuron. Once the action potential reaches the end of the neuron, it triggers the release of neurotransmitters into the synaptic cleft to communicate with the next neuron.
The threshold potential must be reached for the neuron to fire. This is the level of depolarization that triggers an action potential to be generated and propagated along the neuron.
depolarization
despolarization
A temporary accumulation of sodium ions at the axon hillock which yields a voltage sufficient to open voltage-gated ion pores on the axon is what triggers an action potential.
A sudden increase in membrane potential, typically from a resting membrane potential of around -70mV to a threshold potential of around -55mV, triggers the opening of voltage-gated sodium channels leading to depolarization and initiation of an action potential.
When an action potential reaches an axon terminal, it triggers the release of neurotransmitters into the synaptic cleft.
When an action potential reaches the nerve terminal, it triggers the release of neurotransmitters into the synapse.
neurotransmitters from the synaptic vesicles into the synapse. These neurotransmitters then bind to receptor proteins on the adjacent neuron, initiating a new action potential in the postsynaptic neuron.
When an action potential reaches the nerve terminal, it triggers the release of neurotransmitters into the synapse, which then transmit signals to the next neuron or target cell.
When the action potential reaches the axon terminal, it triggers the release of neurotransmitters into the synapse, which then bind to receptors on the neighboring neuron, continuing the signal transmission.
Following a threshold potential, voltage-gated sodium channels open, allowing sodium ions to rush into the cell, depolarizing the membrane. This triggers an action potential that spreads down the length of the neuron. Once the action potential reaches the end of the neuron, it triggers the release of neurotransmitters into the synaptic cleft to communicate with the next neuron.
The threshold potential must be reached for the neuron to fire. This is the level of depolarization that triggers an action potential to be generated and propagated along the neuron.
The axon hillock is the part of the neuron that is capable of generating an action potential. It integrates incoming signals from the dendrites and, if the threshold is reached, triggers the action potential to be propagated down the axon.