Re: Amygdala

Hi Jordi,

Thanks for the interesting question. I have to admit, I had some trouble locating this journal article, as my library does not subscribe. Sorry for the delay.

I believe that Pulvermuller & Schumann were referring the role that the amygdala plays in attaching emotional significance to learning, that is, it's role in (perhaps) "reward." The arguement being that the motivation for learning is somewhat derived from an anticipated reward of learning the behavior (though it need not be an operant reward). This could manifest as an indifference to pleasure or pain. [So, is the amygdala the seat of the "id?" ;) ]

To be quite honest, I do not know the answer to your question, directly. However, I must say that there is some evidence to suggest that these monkeys live a normal life-span. Well, at least I think it unlikely that they die from starvation or thirst.

• 1. The brain area mostly responsible for food and water intake is the hypothalamus, or more precisely, particular nuclei in the hypothalamus. There are particular areas (somewhat inappropriately) termed the "hunger center" and the "satiety center." Animals that are lesioned in the hunger center will not eat until they die, and animals lesioned in the satiety center will eat until so obese, they die. Of course there are exceptions: if you feed a "hunger-lesioned" rat chocolate milk, it will eat (rats appearantly LOVE choclate milk).

  Click here for an MRI through the hypothalamus from the Whole Brain Atlas at Harvard University.

• 2. Another line of evidence to suggest that amygdala-lesioned animals live a normal life-span is from operations performed to remove epileptic foci from drug-resistant epileptic patients. Often times, these patients have seizures so severe that the only recourse is to surgically retract the entire temporal lobe (amygdala, hippocampus, etc.). These patients also do not die from thirst or hunger. However, they may not live so long, but probably for other reasons. Somewhat coincidentally, the first reports (1930's) to describe the a temporal hemispherectomy, termed Kluver-Bucy syndrome after the scientists that did these experiments, reported the behavior of hyper-orality. That is, these animals stuck everything into their mouths regardless of it's nutritive value.

As always, you can stop by the AMYGDALA HOME PAGE and check out some of my brain links.