Like synapses between neurons.

Synapses can be created, and they can be eliminated.

Synapses can be created, and the can be eliminated

And synapses can grow larger, and they can grow smaller.

And synapses can grow larger, and they can grow smaller.

Now, at this point, you've learned the basics of neurons and synapses.

Those are synapses, electric impulses in the brain that carry all the messages.

Each neuron is connected via synapses to up to 10,000 other neurons in your brain.

But non spiking neurons are actually quite complicated because they can have input synapses and output synapses all interdigitated, and there's no single action potential that drives all the outputs at the same time.

And in this slide you see the neurons and the synapses of the brain don't form.

It's partly dependent on the environment that the animal or the human is in, and the synapses that are being used are strengthened, and synapses that aren't being used in that particular environment are pruned away.

So all of those colored lines correspond to bunches of axons, the fibers that join cell bodies to synapses.

One neuron can be connected to so many other neurons, because there can be synapses at these points of contact.

And you can see that the green neuron touches the red neuron at two locations, and these are what are called synapses.

Now that might sound bad, but actually this is a really important developmental process, because gray matter contains cell bodies and connections between cells, the synapses, and this decline in gray matter volume during prefrontal cortex is thought to correspond to synaptic pruning, the elimination of unwanted synapses.

I figured out 100 billion clicks per day, 55 trillion links is almost the same as the number of synapses in your brain.

Because, if the first neurons in the chain are activated, through their synapses they send messages to the second neurons, which are activated, and so on down the line,

We color every neuron in, in a different color, and then we look through all of the images, find the synapses and note the colors of the two neurons involved in each synapse.

And we are just beginning to understand, how to even study it, whether you are thinking about a hundred billion neurons in the cortex or a hundred trillion synapses that make up all the connections.

It depends, of course, on what scale or what scope you want to think about, but this is an organ of surreal complexity, and we are just beginning to understand how to even study it, whether you're thinking about the 100 billion neurons that are in the cortex or the 100 trillion synapses that make up all the connections.