inactivation of voltage-gated sodium channels and the opening of voltage-gated potassium channels

the neuron's membrane voltage becomes more positive

Each neuron receives input from one or more cells. In response, the neuron may generate an electrical signal known as an action potential that travels down the length of the axon.

A single neuron can receive signals from many sending neurons. Two sets of signals - excitatory and inhibitory cancel each other out and no action potential is generated.

The synaptic terminal of a sending neuron contains numerous vesicles filled with neurotransmitters, chemicals that carry information across the synaptic cleft. When an action potential reaches the synaptic terminals, the vesicles fuse with the plasma membrane of the sending neuron, releasing neurotransmitters into the synaptic cleft. The neurotransmitters affect the receiving neuron, changing the distribution of charge across its membrane. An action potential is propagated down an axon by the opening and closing of sodium and potassium channels. When an action potential arrives at the synaptic terminal, it causes the opening of calcium channels. Calcium ions enter the synaptic terminal through the calcium channels. Calcium ions bind to the vesicles containing neurotransmitters. This causes the vesicles to fuse with the plasma membrane of the sending neuron, releasing neurotransmitters into the synaptic cleft. The neurotransmitters diffuse across the synaptic cleft and bind to receptors in the plasma membrane of the receiving neuron. Neurotransmitters are quickly removed from the synaptic cleft, ending their effect on the receiving neuron

the neuron's membrane voltage becomes more positive

Signals are passed from a sending neuron to a receiving neuron at a junction called a synapse. An action potential in the sending neuron travels down the axon until it reaches a synaptic terminal. The narrow gap between the synaptic terminal and the receiving neuron is called the synaptic cleft.

The membrane of an axon is also packed with gated ion channels that open and close during an action potential. At resting potential, the gated channels are closed. If a stimulus changes the distribution of charge across the membrane sufficiently, the gated sodium channels open. Movement of sodium ions across the membrane makes the inside of the cell more positive. This reversal of the charge distribution causes the gated sodium channels to close and the gated potassium channels to open. As potassium ions move out of the cell, the original charge difference is re-established across the membrane, closing the gated potassium channels. This sequence of events is called the action potential. The sodium-potassium pump restores the distribution of ions back to their levels at resting potential.

A single neuron can receive signals from many sending neurons. Two sets of signals - excitatory and inhibitory cancel each other out and no action potential is generated.

As the change in charge difference across the membrane spreads from open sodium channels, other sodium channels farther along the axon begin to open. The original sodium channels close and adjacent potassium channels open. As potassium ions move out of the cell, the original charge difference across the membrane is restored and then the potassium channels close. Meanwhile, new sodium channels open, followed by the opening of new potassium channels and the closing of sodium channels. In this manner, the action potential is propagated along the axon of the neuron, eventually reaching another cell. The information carried by this action potential will be processed with other information.

Even without an action potential, the axon is a busy place, with many ions moving across its membrane. Much of this ion movement is driven by the sodium-potassium pump. Using energy from ATP, sodium potassium pumps actively transport sodium ions out of the cell and potassium ions in creating an uneven distribution of charge across the membrane. Some potassium channels are open all the time, allowing potassium ions to leave the cell. As a result of these ion movements, the inside of the cell is negative relative to the outside. This condition is called the resting potential

the postsynaptic membrane

The membrane of an axon is also packed with gated ion channels that open and close during an action potential. At resting potential, the gated channels are closed. If a stimulus changes the distribution of charge across the membrane sufficiently, the gated sodium channels open. Movement of sodium ions across the membrane makes the inside of the cell more positive. This reversal of the charge distribution causes the gated sodium channels to close and the gated potassium channels to open. As potassium ions move out of the cell, the original charge difference is re-established across the membrane, closing the gated potassium channels. This sequence of events is called the action potential. The sodium-potassium pump restores the distribution of ions back to their levels at resting potential.

As the change in charge difference across the membrane spreads from open sodium channels, other sodium channels farther along the axon begin to open. The original sodium channels close and adjacent potassium channels open. As potassium ions move out of the cell, the original charge difference across the membrane is restored and then the potassium channels close. Meanwhile, new sodium channels open, followed by the opening of new potassium channels and the closing of sodium channels. In this manner, the action potential is propagated along the axon of the neuron, eventually reaching another cell. The information carried by this action potential will be processed with other information.

Even without an action potential, the axon is a busy place, with many ions moving across its membrane. Much of this ion movement is driven by the sodium-potassium pump. Using energy from ATP, sodium potassium pumps actively transport sodium ions out of the cell and potassium ions in creating an uneven distribution of charge across the membrane. Some potassium channels are open all the time, allowing potassium ions to leave the cell. As a result of these ion movements, the inside of the cell is negative relative to the outside. This condition is called the resting potential

The synaptic terminal of a sending neuron contains numerous vesicles filled with neurotransmitters, chemicals that carry information across the synaptic cleft. When an action potential reaches the synaptic terminals, the vesicles fuse with the plasma membrane of the sending neuron, releasing neurotransmitters into the synaptic cleft. The neurotransmitters affect the receiving neuron, changing the distribution of charge across its membrane. An action potential is propagated down an axon by the opening and closing of sodium and potassium channels. When an action potential arrives at the synaptic terminal, it causes the opening of calcium channels. Calcium ions enter the synaptic terminal through the calcium channels. Calcium ions bind to the vesicles containing neurotransmitters. This causes the vesicles to fuse with the plasma membrane of the sending neuron, releasing neurotransmitters into the synaptic cleft. The neurotransmitters diffuse across the synaptic cleft and bind to receptors in the plasma membrane of the receiving neuron. Neurotransmitters are quickly removed from the synaptic cleft, ending their effect on the receiving neuron