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This video explains neuron graded potentials, detailing how they are created and why they decay over time and distance. It highlights the role of neurotransmitter receptors and ion channels in generating excitatory and inhibitory potentials, providing a clear understanding of neuron function. Created by Matthew Barry Jensen.

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• if there are 1000 synapses per neuron in the brain than that would mean 1000 neurotransmitter receptors which means that the number of cells in the brain is a power of 1000 + 1. of course there aren't the same number of neurons all over the brain. Different parts have different densities. How can I calculate the number of neurons on average in a specific area of the brain from the average size of a neuron and the size of that part? The equation would be x(number of neurons total) = y(size of neuron)/z(number of neurons per unit). but how would I know what y and z are especially z?
• Who said there is one neurotransmitter receptor in a synapse? In fact there are many in each synapse. Also, even if your hypothesis was correct(which it most certainly isn't), your equation is wrong. the # of neurons= the density(mass of neurons(in kg)/volume(in L)) x (#neurons/ 1 kg) x the volume of the part you're looking at (in Liters). But even that equation would negate the existence of the various tissues of the brain. Here is a fun fact. The brain is mostly glial cells--in fact they outnumber neurons as much as 50:1.

All that being said, I love the curiosity. Keep it up.
(1 vote)
• So is the diffusion force always greater than the electrical force?
• In general yes. This is because there are multiple species with like charges (Ca++, Na+, K+).
• I just wanted to clarify something. When Na+ ions are pumped in and a hemisphere of Na+ ions in created. I understand that they diffuse throughout the cell. Why do they not cause a a slight decrease in the voltage (Say 60mV to 59mV) that is constant over time, once they have all spread out evenly throughout the cell?

Is it because the cell has a mechanism to always be pumping these Na+ ions out?
• I think the difference is negligible and is more or less balanced by the leak channels
• Is a graded potential the same as a local potential?
• What is THC? How does it affect synapses?
(1 vote)
• THC is Tetrahydrocannabinole and it inhibits the irritability of every neuron in the nerve system.
• Hi, great video again! I just have a quick question about the graded potential. If the resting potential is -60mV and the threshold potential is -50mV, can the graded potential be greater than -50mV? Or once it pass the threshold, it will become action potential? Thank you! This has been bugging me for soooo long..
(1 vote)
• Action potentials are "all-or-nothing"; as soon as a potential is stimulated to exceed the threshold potential, the action potential will be activated and the cell will depolarize.
• So would memory recall be a graded potential, with the information only accessible if enough synapse-dendrite connections are present?
(1 vote)
• We don't even know how the brain stores the information, let alone recalls it. Formation of memory is an incredibly complex process and there is still not much knowledge about it.