[Neuroscience] Re: The Placebo Effect on the Rat Immune Response

Glen M. Sizemore via neur-sci%40net.bio.net (by gmsizemore2 from yahoo.com)
Sun Dec 9 09:12:21 EST 2007

"John H." <johnh from goawayplease.com> wrote in message 
news:13ln9jgfhk61d62 from corp.supernews.com...
> In the space of 3 days I have read two books citing this experiment and it 
> is baffling. Please don't try and wash it away with a rationalisation of 
> the dumbass kind, it is very obvious to any honest clinician that a 
> person's attitude can have a profound effect on disease progression. Nor 
> is this spooky, the problem can be couched within a 
> neuro-endocrine-immunological axis of understanding; though I admit that 
> paradigm certainly cannot explain all that comes under the umbrella of the 
> placebo effect. So it still might be spooky ...
> In this experiment the Bob Ader and Nick Cohen decided to see if the 
> immune system could be trained to respond to a conditioned stimulus. The 
> paired the sweet taste of saccharine wtih an anticancer drug that 
> suppresses immune immune function, cyclophosphamide. They fed the drug and 
> the saccharine to the rats over and over again. Each time the 
> immunosuppressive drug was given the immune cell count went down. Then 
> they took away the drug and just gave the saccharine alone. The immune 
> cell count fell again. Before the conditioning process the saccharine had 
> no impact on immune cell count.
> I cannot find a way to understand this. Yes the brain and immune systems 
> do influence each other great deal but nothing in our current 
> understanding can explain this.
> Now if the placebo effect is about suggestion then these are very clever 
> rats. You might want to look up the Norman Cousins and Henry Beecher. Then 
> you'll really get confused. (Those two instances I can offer a plausible 
> explanation but this one has me stumped.)Why the placebo effect is ignored 
> is beyond me. I suspect it simply doesn't fit into our current 
> understanding so people wash it away with some dumbass explanation. This 
> is what happened to Ader and Cohen, initially their results were treated 
> with derision. If anyone knows if someone has come up with an explanation 
> for this effect I sure would like to hear it.

It is not clear to me what you are asking here, John. In one sense the 
answer is "it is classical conditioning." Now, if your question involves 
"the neurobiology of classical conditioning" and this effect in particular - 
good luck. As I have said many, many times here, the way physiology mediates 
behavior is largely unknown (despite the arm-breaking self-back-patting of 
neurobiologists). We cannot explain something as "simple" as how a rat comes 
to press a lever after exposure to the necessary contingencies.

> John.

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