Gordon Johnson: Doctor, when we broke we were holding the temporal lobes with the hippocampus and the foreign structures that are shown. We are now going to turn to the model of an actual human brain that we have and this is a reconstruction from actual MRI images, is it not?
Dr. Erin Bigler: That is correct.
Gordon Johnson: The starting point is with what I have in my hand on this brain and you can introduce what we have and then explain show that.
Dr. Erin Bigler: Sure, so this is pretty straightforward. This is a side view of the brain. These are the sulci, here. These are the bumps or the, gyri. Now it’s all color coded because it’s actually separating out the different gyri that are present in the brain. For example if I click right here, it, actually tells me the different part of the brain that I’m looking at. So, we can also manipulate this brain and I’m going to show you the base of the temporal lobe by swinging it around.
Gordon Johnson: So that would be essentially like this?
Dr. Erin Bigler: That’s that view.
Gordon Johnson: All right.
Dr. Erin Bigler: So what we’re going to do, is we’re going to go to what are called the “subcortical structures”. Now, what we’re going to be looking at is we’ve taken away the, so basically we’ve taken away the hemisphere like this. Now I’m going to take away the cortex, here on –
Gordon Johnson: This is the cortex, this big?
Dr. Erin Bigler: Yes.
Gordon Johnson: The big parts here.
Dr. Erin Bigler: They are like the bark. Now you can see that I’ve pulled off part of the insular cortex. Notice that looks similar to what it is that I’m showing here. So this outer structure, this right here is part of what’s called the basal ganglia, it’s the putamen. This is the caudate right here in green. This is the caudate and this is part of that red that comes down and connects, with the amygdala because this is a system that connects with the amygdala.
Now I’m going to rotate this up. So if I rotate this up now you can see the brain stem so here’s the pons, the medulla here. But what’s in yellow this is actually and I’ll make this a little bit bigger so we can see it, this is the hippocampus and you can see how it bends around. Yeah, if you hold that up like that you can see that’s exactly what we’re looking at so here is that bend in the hippocampus and here is the bend in the hippocampus. Now it’s sort of obscured in this view.
Gordon Johnson: Is this, would you match up more like this?
Dr. Erin Bigler: Right. It’s that, it’s that position –
Gordon Johnson: Except that the –
Dr. Erin Bigler: You, you couldn’t see it that’s why I turned it.
Gordon Johnson: The temporal lobes are missing.
Dr. Erin Bigler: Yeah. So, here is that connection then. This is the front of the hippocampus and this is the amygdala. So if we turn it this way and just pull this image down and I’ll make it a little bit smaller here so you can see the hippocampus and this is the amygdala. What’s in blue is the ventricle.