Learned something interesting at Skool Tuesday

[GabrielDeafBlindPupFamily]

Every experience we have ever had is stored in our 'limbic system'.

The instructor likened our unconsciousness to a powerful racehorse and our conscious mind to a tiny jockey.

He then described how our limbic system and racehorse determine our every day activities. It was fascinating, and of course, while I should have been applying this to the lesson I was there to learn, I was thinking CCD & seizures as we have discussed in Possum's case. This is what I found as a quick search this morning, looking for a way to erase Possum's limbic 'memory' and give her a clean slate:

http://www.drugtext.org/sub/nervous2.html


Limbic system

The limbic system can best be described as the first beginning of the great brain. Research has given us some idea of how this system works. Both the nature and the results of such research can best be illustrated by the following famous example. The Spanish neurophysiologist DEGADO planted electrodes into a specific part of the limbic system of a Spanish fighting bull and fitted it with a receiver so that when a signal was sent by a transmitter a current would flow through one of the electrodes and stimulate the cells concerned. Once the wound from the operation had healed, the bull was taken to the arena and, in the traditional way, provoked fury by the toreadors. Delgado then entered the arena and provoked the bull which then charged him, head down to take Delgado on his horns.
When the bull was only a few meters away from Delgado, he pressed the button of the transmitter in his pocket which stimulated the bull's brain and the bull calmed down immediately. Efforts by the toreadors to enrage the bull again were unsuccessful as long as Delgado kept stimulating the bull's brain. Only by pressing another button which stimulated a different part of the limbic system could the bull again be brought to a state of rage without the help of the toreadors. Evidently, the cells in which Delgado planted his electrodes requlate rage and tranquillity. The cells concerned are part of the limbic system and are found in the amygdaloid body, the amygdala. In a way similar to this rats and other animals can, by selective stimulation of other parts of the limbic system, be motivated to eat, resp. refuse food, to sexual arousal resp. be made immune to the usual sexual stimulations. In short, the limbic system regulates a number of very vital emotions. This effect can also be elicited in humans:

'The first time we were able to demonstrate that systems in the limbic brain that both start and stop attack behaviour was with patient Thomas R. Thomas' chief problem was his violent rage.... NOTE 2 Electrodes were implanted in his amygdala and the daily stimulation of specific parts of it (the lateral) kept him free from attacks of rage for two months. Since it is not possible to continue this regimen throughout a patient's life, those parts of his amygdala which elicited an attack of rage when stimulated (the medial) were destroyed electrically. His attacks of rage subsequently stopped. This operation was, incidentally, thereason for a lawsuit between the two neurosurgeons and the mother of Thomas R. who had fought the operation NOTE 3 . The court's decision is unknown to the author.

In this connection it is striking that disorders in these regulating mechanisms lead to behavioral disorders which, though not necessarily seen by all as addictions, are nevertheless seen as 'cravings': bulimia, anorexia nervosa, gambling fever, etc. We may assume that the addictive effect of some drugs is connected with their influence on the receptors in the limbic system.

Furthermore, the limbic system influences the hormonal system by means of the hypophysis (pituitary gland), a small gland attached to the base of the brain. Finally, the limbic system, especially that part to do with the hippocampus, plays a very important role in memory.

The limbic system is already somewhat developed in fish and reaches full development in the reptiles. In rudimentary form its main function is processing olfactory stimuli; later, this function shifts to regulating emotions. An echo of this old function can be seen in the fact that no sensory stimulation can elicit stronger emotions than a smell. The human limbic system is virtually no different than that of the reptiles. It represents the 'crocodile' in us.

Subcortical centers

These are the communication stations between the brain stem and the limbic system on the one hand and the cerebral cortex on the other. The complicated behavior patterns are organized here. In this connection an important part of these centers, which some think are a part of the limbic system, is the nucleus accumbens.

The role these centers play becomes clear with experiments in which laboratory animals with a permanently implanted electrode or a permanent infusion stimulate themselves by pressing a button. When such an electrode is implanted in the nucleus accumbens, and the laboratory animal realizes that the sensation it is getting is caused by pressing the button, the feeling is so pleasurable that the animal will lie down on the button. Other locations in this center have the reverse effect. The theory now is that this center functions as a kind of punishment/reward center in the sense that eating when you are hungry also stimulates the reward center, while with satiation the punishment center is stimulated if you then continue to eat. Stimulation of this center could, then, give a feeling of reward, without there necessarily being any 'rewardable' behavior. Why should you eat, drink, etc. if you can also elicit the ultimate feeling of reward by electrode (or by a needle in your arm)?


It is something for me to further research... hmmmm....