how do electrical impulses happen in the brain?

Question

where does the energy come from?

Answer 1

I'll start with the easier question first: energy for your brain comes from the same place the rest of your energy comes from. In fact, your brain alone is generally responsible for about 30% of your resting energy usage!

It bears mention that the 'electrical impulses' along nerve cells are not quite like the electricity running along an electric wire. Electricity in a wire involves a movement of electrons in mostly stationary atoms. Fast and easy. The impluses in your brain involve movement of entire charged atoms. Which works pretty well for what it does, but compared to wires it's slow and difficult. Chemical instead of electrical.

What your brain does is a LOT like 'the wave' in a sports stadium (if you know what I'm talking about). Along any given stretch, it will start building up an imbalance of charge. Using energy to put a bunch of + atoms on one side and a bunch of - atoms on the other. Since +'s and -'s like to be next to each other, this creates a potential... a kind of stored energy.

Then, when a particular section of one neuron notices that his neighbor has let go, he does so also. The channels are opened and everything balances out in the huge rush. And his other neighbor notices and does the same. Thus you get a 'signal' that 'moves' along the length of the nerve cell.

As soon as it opens the channels, it works again to restore that potential again, so things quickly return to normal. You might think of it as being like a line of guys holding bouncy balls. When you see the guy next to you drop his, you drop yours and catch it again. Ta-da! A signal.

Because electrically charged atoms are moving around, it DOES create an electromagnetic signal which can be detected with the right instruments. And it wouldn't work at all without the electric force, which is what makes those +'s and -'s want to be next to each other. But what is REALLY moving is atoms.

Hope that helps!

Answer 2

The energy comes from electric potential. Every nerve cell has a whole lot of potassium in it, as well as chlorine ions, and not a lot of sodium ions.

When a nerve cell is triggered by some stimulus, it lets in a bunch of sodium axons, and this causes the cell's electrical charge to become more positive (more positive ions inside the cell). This electrical impulse in the area where the potassium is dumped then moves along the cell's axon (long arm), where the charge causes the release of neurotransmitters.

These neurotransmitters then trigger the next cell down the line.

Answer 3

A receptor or sense organ picks up stimulus and converts it into a nerve impulse. This impulse is then conducted along a neural pathway to the brain, where the signal is converted into a sensation.
Neurons, specialized cells of the brain and nervous system, communicate via a relay system of electrical impulses and specialized molecules called neurotransmitters.
A neuron generates an electrical impulse, causing the cell to release its neurotransmitters. The neurotransmitters, in turn, bind to nearby neurons. The recipient neurons then generate their own electrical impulses and release their own neurotransmitters, triggering the process in still more neurons, and so on.

Answer 4

Electrical impulses in the brain are due to the firing of action potentials between neighboring neurons. Each neuron has protein channels that either close or open, in the presence of Ca+, K+, Na+, or Cl- ions. When Na+ channels open, sodium rushes in, greatly depolarizing the cell, and establishing an electrochemical gradient. If the electrochemical gradient of the neuron overcomes the threshold close to the axon hillock (where the axon connects to the neuron), then the gradient is spreads to the axon.

Axons are composedo of myelin sheaths that serve as insulating nodes, propagating the signals at higher and efficient speeds. Keep in mind that channels open and close, thus letting ions through-this keeps the action potential from dismantling. Once the action potential reaches the Axon terminal, it stimulates vesicles in that section of the cell to release calcium, which in turn stimulates the release of neurotransmitters through the synapse.

Answer 5

The cell membrane of the neurons acts like an electrical capacitor, because the inside of the cell has a different concentration of various ions such as sodium and potassium. Since this concentration is different from the one outside the cell, it can gather potential energy this way. The membrane has channels, or pores through which it can either release or capture ions from the external source and therefore change the potential, which it tries to keep as different from the one outside it as it possibly can without damaging itself. When synapsis, or brain activity starts, these channels open and the potential changes rapidly. This difference in ion concentration creates a difference in electrical charges, and so, generates electricity.