When Can A Fetus Feel Pain? Ctd

Jul 22 2013 @ 8:33am

A reader writes:

I am a pediatric intensive care unit physician with 13 years experience in the field. The idea that an organism that withdraws from something that would be considered painful in a person with an intact nervous system is therefore experiencing pain and suffering is incorrect. The idea that an associate professor of neurobiology would make that assertion seems to smack either of incompetence or speciousness.

Withdrawing from a pinch or burn is not a decision or a response to pain, but a spinal cord reflex. When you touch a hot surface, you don’t think “Jesus, that hurts!” and then withdraw your hand. You yank your hand back and think “aw crap, that’s going to hurt in a second … yep, there it is!” The nerve circuits that produce the reflex withdrawal go from the sensory apparatus to the spinal cord, and then right back to the muscle. No brain involved. They are also considerably faster than those fibers that go to the spine, the brain stem, the thalamus, and then the cortex to be perceived as pain. Although the “fetal neural structures” might be in place, simple withdrawal doesn’t prove that those structures go any higher than the spinal cord.

I run into this problem about once a month when we are forced to declare “brain death” in children who are the victims of violence – car wrecks, ATV accidents, gunshots, etc.

These unfortunate people have no detectable brain activity of any kind and are legally dead. But if you pinch their toe hard enough, you can produce what’s called the triple flexion reflex. This is not obscure knowledge – we teach it to residents all the time. And it’s certainly something that an associate professor of neurobiology should be very familiar with.

This ultimately gets to the question of what pain is, and what suffering is. People whacked out on dilaudid can report something as being painful, but it’s as if it is happening to somebody else and they just don’t care. Are they still “in pain” and need more medicine, or is the fact that they’re not suffering sufficient? I believe that the “fetal neural structures” might be in place to have the electrical activity associated with parts of the pain sensation in people with more-developed neurological systems. I do not believe that an organism without a cortex is capable of suffering. And that’s really what we’re talking about, isn’t it?

Update from a reader:

You might find this relevant to your discussion. In my research lab we’re culturing cortical neurons in special petri dishes called “multi-electrode arrays” that allow us to record electrical activity directly from the cultures. We use this setup to study how neurons create and modify electrical connections. Typically we use cortical neurons from fetal rats. This tissue is harvested on day 18 of gestation, just three days before birth. The neurons typically culture easily and start firing right away.

Recently, however, we’ve been able to get access to some human fetal cortical tissue. These cells come from aborted human fetuses. I’m not certain of the gestation period but its almost certainly early 2nd trimester. We’ve recently started culturing these cells and we’ve discovered something amazing. Whereas the rat neurons start firing almost immediately, the human neurons must culture for close to two months before they’ll start spontaneously firing in a way that is consistent with typical normal brain behavior. This is a stunning finding and breaking news to boot; my grad student only told me about all this on Friday! It seems that neurons that are too early into the gestation cycle are not sufficiently mature to produce firing patterns that one would associate with normal brain function.

What this has to do with pain or consciousness is anyone’s guess, but it’s almost certainly an important piece of information that no one has discovered before now. We’ll be busy getting this ready for publication in the coming weeks but I thought your readers might enjoy hearing about it first.