The limbic system is often referred to as the "reptile brain."

They come from the reptile brain, the censor and the id.

My dumb reptile brain had registered them only as sounds.

Deep in the primordial reptile brain which every sentient person has, I had worked it all out already!

And so too, most emphatically, does the reptile brain.

They say man has a reptile brain in the lower middle of his skull.

Since the amygdala is the reptile brain, this confirms what I've suspect to be true as well.

The reptile brain is the dragon within us.

Then the human level of his mind started to calm the urgent reptile brain.

"He just doesn't know it on the surface level of that reptile brain."