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1. A neurotransmitter (NT) released from another cell (or in some cases the same cell) will diffuse across the synaptic cleft and bind to a recipient receptor.
2. The receptor will then change it's permeability to certain ions in the extracellular fluid, allowing the ions to flux into the cell (the exception here would be pharmacological agents designed to occupy the receptor without leading to a conformation change)
3. The influx of ions will alter the membrane potential. If the NT is inhibitory (e.g. GABA), then the GABA receptor that it binds to will increase its permeability to negatively charged ions (chloride) and thereby lower the local resting membrane potential (which is normally -70mV). If the NT is excitatory (e.g. glutamate) then the glutamte receptor (AMPA or NMDA) will increase its permeability to positively charged ions (sodium) which will increase the resting membrane potential from -70mV.
4. If enough NTs bind then the local membrane potentials will summate - and in the case of excitatory NTs - cause the membrane potential to change (by opening of voltage-gated ion channels) to around 0-20mV leading to an action potential
5. The action potential, which is generated in an 'all or none fashion' at the axon hillock, will then propagate all the way down the axon to the axon terminal causing the release of stored NTs (although not all NTs are stored - e.g. NOS)
6. NTs released from the presynaptic cell will then diffuse across the synaptic cleft and bind their postsynaptic receptor (normally located on a dendrite, although also located on the cell body themselves) and the whole process starts all over again
What else can I help you with?
What enters the axon during action potential?
Sodium ions enter the axon during action potential. This influx of sodium ions depolarizes the axon membrane, leading to the propagation of the action potential along the axon.
During action potential transmission many ions cross the neuronal membrane at right angles to the membrane what travels along the membrane and acts as the signal?
During action potential transmission, the signal is carried along the neuronal membrane by the movement of ions such as sodium and potassium across the membrane. This movement creates changes in the membrane potential, allowing the signal to travel down the length of the neuron.
Why does the polarity of a cell membrane reverse during an action potential?
The reversal of polarity during an action potential is due to the changes in ion concentrations across the cell membrane. When the membrane depolarizes, sodium ions rush into the cell and make the inside more positive. Repolarization occurs when potassium ions leave the cell, bringing the membrane potential back to negative.
What happens in the neurolemma as the result of an action potential?
It provides insulation to the axons and dendrites during depolarization or action potential.
During an action potential hyperpolarization beyond more negative to the resting membrane potential is primarily due to?
Potential hyperpolarization are more negative to the resting membrane potential because of voltage. This is taught in biology.
What happens during an action potential in a neuron?
During an action potential in a neuron, there is a rapid change in electrical charge across the cell membrane. This change allows for the transmission of signals along the neuron.
What enters the axon during action potential?
Sodium ions enter the axon during action potential. This influx of sodium ions depolarizes the axon membrane, leading to the propagation of the action potential along the axon.
During action potential transmission many ions cross the neuronal membrane at right angles to the membrane what travels along the membrane and acts as the signal?
During action potential transmission, the signal is carried along the neuronal membrane by the movement of ions such as sodium and potassium across the membrane. This movement creates changes in the membrane potential, allowing the signal to travel down the length of the neuron.
Why does the polarity of a cell membrane reverse during an action potential?
The reversal of polarity during an action potential is due to the changes in ion concentrations across the cell membrane. When the membrane depolarizes, sodium ions rush into the cell and make the inside more positive. Repolarization occurs when potassium ions leave the cell, bringing the membrane potential back to negative.
What happens in the neurolemma as the result of an action potential?
It provides insulation to the axons and dendrites during depolarization or action potential.
When do voltage gated sodium channels open during an action potential?
Voltage-gated sodium channels open during the depolarization phase of an action potential, when the membrane potential becomes more positive.
During an action potential hyperpolarization beyond more negative to the resting membrane potential is primarily due to?
Potential hyperpolarization are more negative to the resting membrane potential because of voltage. This is taught in biology.
Which is the first step in a neuron production of an action potential?
Depolarization is the first event in action potential. During depolarization, the sodium gates open and the membrane depolarizes.
During the action potential?
During the action potential, there is a depolarization phase where the cell membrane potential becomes less negative, followed by repolarization where it returns to its resting state. This involves the influx of sodium ions and efflux of potassium ions through voltage-gated channels. The action potential is a brief electrical signal that travels along the membrane of a neuron or muscle cell.
When do voltage-gated Na channels open during an action potential?
Voltage-gated Na channels open at the beginning of an action potential when the membrane potential reaches a certain threshold level.
The process of depolarization and repolarization is called?
The process of depolarization and repolarization is called an action potential. During depolarization, the cell's membrane potential becomes more positive, while during repolarization, the membrane potential returns to its resting state.
What changes occur in the neuron during an action potential?
During an action potential, the neuron undergoes a rapid change in membrane potential as sodium ions rush into the cell, leading to depolarization. Subsequently, potassium ions move out of the cell, repolarizing the membrane back to its resting state. This rapid change in membrane potential allows for the transmission of electrical signals along the neuron.
