146 Discussion 



Hess (1955, Nature, Lond., 175, 387) on the ground substance of the brain. 

 It would seem, from the studies of Hess, that disturbances in ground 

 substance mucopolysaccharide, in cerebral tissue in particular, may play 

 an important part in regulating the activity of the neurones themselves. 

 Have similar studies been made by you ? 



Kallmann: No, the brains presented came from patients who died in 

 some of our rural mental hospitals, and only the brain material was 

 received for study. I showed these slides largely to demonstrate 

 differences between changes observed in Pick's atrophy and those 

 observed in Alzheimer's atrophy. Apparently, one can distinguish the 

 two conditions histopathologically, although the given cases were not 

 studied clinically. Our theory is that there has to be some different 

 metabolic disturbance at the roots of these cases, and it is regrettable 

 that we still do not know the nature of the metabolic defect involved. 



Gillman: It would seem that, particularly with modern staining and 

 paper chromatographic methods, the study which I suggested would be 

 reasonably easy to conduct and may be worthwhile. 



Lewis: I think it might be more difficult than that, because since 

 interest was aroused in serotonin and its derivatives, many people have 

 been studying the body fluids of psychiatric patients for such products, 

 and so far very little has come of it. 



Gillman : Have any such studies been done in Alzheimer's and Pick's 

 diseases? 



Lewis: No. 



Friedman: I take it, Prof. Kallmann, that the extension of the 

 lifespan which has occurred in the last half-century would indicate that 

 the genetic characteristic was permissive rather than obligatory ? 



Kallmann: One can talk only in terms of potentials, and different 

 generations may make a different use of their potentialities. It is only 

 those who do not die before the end of their biological lifespans, who 

 can show how long they may live. On the whole, in one-egg pairs we 

 find a relatively close correspondence between the ages reached and the 

 causes of death, shown at death, even in those who have been separated 

 for fifty or sixty years and have lived under different circumstances. In 

 two-egg twins, even in those who have always lived together, we rarely 

 find such a close correspondence. We record these data, we don't pro- 

 duce them experimentally. 



Best: Histological changes in very old people are the same as those 

 in Alzheimer's disease, therefore what is the distinction between the 

 elderly people in whom you do not diagnose this condition and those 

 younger people who have the disease? 



Kallmann: Whatever the senile plaques are, they are an indication 

 of some metabolic disturbance in the brain. Ordinarily, they are not 

 found before the age of 80 or 85. In cases of Alzheimer's disease, how- 

 ever, they are seen in the brains of people dying in their forties or fifties. 



Best: Does that mean that everybody over 85 has Alzheimer's disease ? 



Kallmann: No, everybody's brain may show plaques characteristic 

 of senile processes, apparently as the result of metabolic disturbances 

 which ordinarily occur only in persons who die late in life. 



