1 8 94 



HANDBOOK OF PHYSIOLOGY 



\i i i« ipin mi ii i k;v in 



course of nutritional rehabilitation. Clinical examina- 

 tion of the neurological status yielded largely negative 

 results. There was no impairment in the sense oi 

 vibration. Skin sensitivity remained normal, except 

 for three men who developed mild paresthesias. The 

 patellar and the Achilles tendon reflexes were dimin- 

 ished. 



The components of the capacity for brief neuro- 

 muscular performance — strength, speed and co- 

 ordination — were examined by a battery of tests. 

 Changes in all these functions were statistically highly 

 significant. However, there were substantial differ- 

 ences in the relative amount of deterioration as indi- 

 cated by the displacement ratio (difference divided 

 by the standard deviation of the control values). The 

 largest change took place in the strength measure- 

 ments in which the peripheral factors (size and state 

 of the muscles) limited performance. Performance on 

 tests in which the central nervous system was the 

 critical component, such as the speed of tapping, 

 changed but little. The pattern-tracing, a complex 

 task involving eve-hand-loot coordination and per- 

 formed while the subjects were walking on .1 treadmill, 

 was intermediary in regard to the relative amount of 

 deterioration. 



Measured intellectual performance did not change 

 importantly in spite of subjective complaints about 

 inability to concentrate and the difficulty in develop- 

 ing thoughts. Using 'speed tests' of intelligence in 

 which the working time was short and Strictly limited, 

 no statistically significant decrement was observed in 

 perception of spatial relations, word fluency, short- 

 term memory, inductive reasoning or perceptual 

 speed. In the 'power lests' with no rigid time limits 

 imposed and actual working times of 8 to to hr., the 

 total scores showed .1 minimal decrement at the end of 

 the semistarvation period. This was in sharp contrast 

 to a marked decline in spontaneous mental effort and 

 achievement which only gradually returned to 'nor- 

 mal' mi refeeding. In the psychometric study of 

 personality, a marked rise- was present on the Hypo- 

 chondriasis, Depression and Hysteria scales of the 

 Minnesota Multiphasic Personality Inventor) (132, 

 231). 



PRI ITEIN I'l 1 [I II M V 



protein deficiency (173, 285), but we were unable to 

 secure information concerning changes in brain 

 enzymes. 



Deficiency of some amino acids is known to produce 

 alterations of nervous function. Yaline-deprivcd rats 

 became extremely sensitive to touch and developed a 

 severe incoordination of movements (222). The ani- 

 mals walked with a staggering gait and frequently 

 exhibited a rotary motion which continued until they 

 fell to the cage floor from sheer exhaustion. Later, 

 degenerative changes in the spinal cord were reported 

 17m. 



Dogs on a gliadin diet deficient in lysine developed 

 neurological manifestations resembling those ob- 

 served in 'canine hysteria' (169). Lysine was found to 

 be helpful in preventing the attacks in dogs fed a 

 diet of baked meat scraps and wheat flour (8). 



In research on amino acids and nervous function, 

 most attention has been devoted to glutamic acid and 

 its amide, substances appearing in high concentration 

 in the central nervous system. Glutamic acid can 

 serve as a substrate for oxidative processes in nerve 

 tissues under conditions of insufficient glucose supply, 

 such as insulin hypoglycemia. Nutritionally, glutamic 

 acid is classified as a nonessential amino acid, readily 

 synthesized in mammalian organisms. Furthermore, 

 it is contained in substantial amounts in animal and 

 vegetable proteins. In the majority of clinical studies 

 on the effects of glutamic acid administration, little 

 or no attention has been paid to the amount of glu- 

 tamic acid provided in the diet. Patients given supple- 

 ments of glutamic acid arc expected, then, to benefit 

 from the addition of limited amounts of a substance 

 which is provided, in relatively large qualities, in the 

 dietary proteins. It is perhaps not surprising, under 

 these conditions, that well-controlled studies on the 

 effects of glutamic acid on intelligence tend to yield 

 negative results I I (| ;, I (| | I. 



I'ln- mechanism of improvements reported in some 

 studies, beyond the range of random fluctuations, is 

 uncertain. They mav represent a real improvement in 

 intelligence or .1 better utilization of existing intellec- 

 tual abilities through improved emotion.il control. 

 Waelsch (283) favored the second alternative. He 

 commented that a valid appraisal of the value oi 

 glutamic acid supplementation will require a better 

 differentiation oi the types of mental defectives 



In 1 nun .1st to the liver, which suffers .1 large loss of 

 protein during stravation, the brain shews onl) a verj 

 small 1 hange in protein contenl under the same 



COndi (2). Liver enzymes are depleted during 



/, ,. ashiorkoi 



The term, with .1 v.irietv oi equivalents in other 

 areas, refers to protein malnutrition seen in African 



