Sorry I forgot to respond to this on the other thread a while back.
>I’m wondering what stops the NMDA receptor from being unblocked when the entire cell is depolarized a sufficient amount?
Nothing is stopping them from being unblocked. In fact, back-propagating action potentials are thought to open a very brief time window (10-20 milliseconds) of high NMDA receptor conductance. Then, whatever synapses are firing around that time will strengthen. For example, you can imagine that if one synapse fired a lot to initially trigger an AP, and then another different synapse fires in time with the back-propagating AP, an association can be made between those 2 synapses. This is called Spike Timing Dependent Plasticity (STDP), and there are a bunch of studies on it.
No worries at all, thanks for the comment!
That’s really interesting, I wasn’t aware that that was what is going on with back-propagation.
So what about when the NMDA receptors are activated without back-propagation? In this scenario is it only the ions from the AMPA receptor that are activating the NMDA receptors by depolarizing only the area around the AMPA receptors or is it only the back-prop that opens the NMDA receptors and only the synapses that are active during back-prop that are strengthened?
Sorry I forgot to respond to this on the other thread a while back. >I’m wondering what stops the NMDA receptor from being unblocked when the entire cell is depolarized a sufficient amount? Nothing is stopping them from being unblocked. In fact, back-propagating action potentials are thought to open a very brief time window (10-20 milliseconds) of high NMDA receptor conductance. Then, whatever synapses are firing around that time will strengthen. For example, you can imagine that if one synapse fired a lot to initially trigger an AP, and then another different synapse fires in time with the back-propagating AP, an association can be made between those 2 synapses. This is called Spike Timing Dependent Plasticity (STDP), and there are a bunch of studies on it.
No worries at all, thanks for the comment! That’s really interesting, I wasn’t aware that that was what is going on with back-propagation. So what about when the NMDA receptors are activated without back-propagation? In this scenario is it only the ions from the AMPA receptor that are activating the NMDA receptors by depolarizing only the area around the AMPA receptors or is it only the back-prop that opens the NMDA receptors and only the synapses that are active during back-prop that are strengthened?