Membrane Potential Explained: Neuron Charge, Ion Balance, and Resting Potential

Neuroscientifically Challenged

Membrane potential is one of the key ideas behind how neurons work, and this quick neuroscience lesson breaks it down in a simple, memorable way. The explanation focuses on the difference in electrical charge between the inside and outside of a neuron, created by the uneven distribution of ions across the cell membrane.  You’ll learn how sodium, potassium, chloride, and organic anions are arranged when a neuron is at rest, and why the inside is more negative than the outside. The role of the sodium-potassium pump is also explained, along with how potassium moves through ion channels until it reaches equilibrium. That resting membrane potential, around -65 to -70 mV, is the foundation for understanding action potentials and basic neurophysiology.  Ideal for students, educators, and anyone looking for a clear neuroscience tutorial, this short educational video works well as brain science study material, classroom support, or a fast refresher on neuron membrane potential, ion channels, and the sodium-potassium pump.  SEO: neuroscience education, membrane potential explained, neuron resting potential, action potential basics, sodium-potassium pump, ion channels, neurophysiology, brain science tutorial, biology study aid, and quick science learning for students and curious viewers.

Transcript

00:00Welcome to Two Minute Neuroscience, where I simplistically explain neuroscience topics

00:04in two minutes or less.

00:05In this installment, I will discuss membrane potential.

00:08Membrane potential refers to the difference in electrical charge between the inside and

00:12the outside of a neuron.

00:13This is the plasma or cell membrane of the neuron.

00:16It separates the inside of the cell from the outside environment.

00:19We'll say this is the inside, and this is the outside of the neuron.

00:23The difference in electrical charge develops due to the grouping of ions on the inside

00:26and the outside of the membrane.

00:28Ions are atoms that have either lost your gate electrons and thus have a positive or

00:32negative charge.

00:33There are several ions that play an important role in the membrane potential of neurons.

00:37There are positively charged sodium ions, represented by these blue circles, and negatively charged

00:42chloride ions, represented by these green circles.

00:45When a neuron is at rest, the sodium ions and chloride ions are more prevalent outside of

00:49the cell.

00:50There are also positively charged potassium ions, represented by these yellow circles, and

00:55various negatively charged ions, often referred to as organic anions, represented by these gray

01:00circles.

01:01Anion is simply a term for a negatively charged ion.

01:04When a neuron is at rest, the potassium ions and organic anions are more prevalent inside

01:08the cell.

01:09At rest, the inside of the neuron is more negatively charged than the outside, causing the resting

01:13memory potential of an average neuron to be around negative 70 millivolts.

01:18One way this potential is maintained is through a mechanism known as the sodium-potassium pump.

01:22This is a transport protein that uses energy to constantly pump three sodium ions out of

01:27the cell, while at the same time pumping two potassium ions into the cell.

01:31Because there are more positive ions being pumped out than in, it helps to keep the membrane

01:35potential negative.

01:37Unlike other ions, potassium tends to move fairly easily across the cell membrane through

01:41ion channels, which are membrane-spanning proteins that allow ions to pass through.

01:46Potassium will pass out of the neuron until it reaches the point where it is at an equilibrium.

01:50When forces like diffusion aren't pushing it in one direction or the other.

01:54At this point, the membrane potential of the neuron is around negative 70 millivolts,

01:57which is known as the resting membrane potential.

01:59Topпа of social media,gendeineона

01:59or

01:59hopes

01:59to

01:59video

01:59have

01:59control

01:59Ed

01:59We

02:00Have

02:01See

02:01quello

Category

Transcript

Recommended