I don't know about the blood connection to the brain that you mentioned but the heart and brain connection is interesting. I used to wonder when they did a heart transplant if that heart was in some way imprinted with the memories of the person who made the donation ..(that's weird to try and explain). I was not surprised to learn that when they are removing the heart from the
deceased person they actually clip nerves to the heart that were directly connected to the brain. On a simple level I guess that explains why when you get frightened your heart rate increases and your heart is as much affected as your mind is with the fright. I know it's crazy what we can be curious about but it had also occurred to me that when a person is beheaded that I for one didn't think the brain was instantly dead and must be aware at least on some level what has happened! My reasoning was that the brain is capable of living a maximum (or so we have been taught)for up to 4 minutes without oxygen. I was not too surprised to learn that even in a beheading that the brain is in fact aware of what has occurred; which is horrible to say the very least. I could quote you some specific examples of this from a book I have with some experiments they did of people after death. It's not a good book to read if you're squeamish.