Biology Forums - Study Force

Chemical synapses transmit information from the sending (presynaptic) cell to the receiving (postsynaptic) cell in the form of neurotransmitters. The release of neurotransmitter into the synaptic cleft and the resulting changes in the membrane potential of the postsynaptic cell (postsynaptic potentials) all depend on the presence of several different types of gated ion channels and the distribution of these channels in the pre- and postsynaptic cells. The image here illustrates a chemical synapse.

Voltage-gated Na+ and K+ channels are found only in membranes that propagate action potentials. Membranes found in a chemical synapse that propagate action potentials are the membrane of the synaptic terminal, including the presynaptic membrane, and the membrane of the axon hillock (and axon) of the postsynaptic neuron.

Voltage-gated Ca2+ channels, which help regulate the release of neurotransmitter from the presynaptic neuron, are found only in the presynaptic membrane. Ligand-gated ion channels, which open in response to neurotransmitter in the synaptic cleft, are found only in the postsynaptic membrane.

Finally, there are no gated ion channels in the plasma membrane of the cell body of the postsynaptic cell. For this reason, postsynaptic potentials are not propagated along the membrane of the postsynaptic cell in the same way that an action potential is propagated along a membrane containing voltage-gated Na+ and K+ channels.

Content hidden

There are no gated ions channels in the plasma membrane!

Always remember that the Na can only create an action potential once it reaches the axon hillock!

Thanks for this! :)

Remember, postsynaptic potentials are not propagated along the membrane of the postsynaptic cell because there are no gated ion channels in the plasma membrane of the cell body of the postsynaptic cell.

This is exactly what I needed, thanks so much for the help! :)

What is the difference between synaptic, pre synaptic and post synaptic cells?

Where the neurotransmitter is released.


This is where the neurotransmitters bind and subsequently initiate an action potential.

(http://www.rndsystems.com/resources/images/6436.gif)

Thanks this helped!

It's important to point out that postsynaptic potentials are not propagated along the membrane of the postsynaptic cell since there are no ion channels in the plasma membrane of the cell body of the postsynaptic cell.

So, Because the ATP production is created by the ETC, you have considered that in your answer

thank you!

Thanks for this!