1854 HANDBOOK OF PHYSIOLOGY -' NEUROPHYSIOLOGY III 



TABLE 3. Human Cm >n a! .\ lila hi, lii Rait in I 'arious Abnormal Stairs . 1 wmiatrd with Impaired Mental Function 



* Median of reported mean values (see table 1 for list of references 1. 



local circulation of the cat brain (109, 174), and 

 changes in blood flow may reflect simply the altcra- 

 lions iii the functional and metabolic activity of the 

 (issues subserved. 



I In- metabolic rate indicates only the gross energ) 

 requirements of the brain. Determination of the 

 i flanges in concentrations of various intermediate 

 metabolites in brain tissue sampled from animals 

 during various experimental states lias yielded some 

 information on the pathways oi energy transfers and 

 the nature oi some <>l the intermediate biochemical 

 processes associated with functional activity (141) 

 I'm example, in the cat brain Olsen & Klein (1 |6) 

 found during convulsions a decreased concentration 



"i gl se, glycogen, adenosine triphosphate and 



.M ttim phosphate, and an Increase in adenosine 

 diphosphate, inorganic plnispli.nr and lactic acid 



Pyruvate and hexosephosphate were relatively un- 

 changed (136). The results of similar studies in rat 

 brain were in general the same (27). These changes, 

 indicative of an elevated rate of glycolysis and a 

 depletion of high-energy phosphate stores, reflect 

 the higher energy demand of the increased functional 

 activity associated with convulsions. In addition, 

 -Mnlies in rats have demonstrated cyclic decreases 

 and restorations of the acetylcholine levels in the 

 brain during electrically induced convulsions (142) 

 and ,1 significant liberation of ammonia ill association 

 with electrical or other types of stimulation (14:5b 

 During anesthesia, .1 condition of reduced functional 

 activity, changes in the opposite direction occur. 

 Thus, the 1. H lie acid content of the brain is reduced 

 .mil the in. nine phosphate and ATP contents in- 

 creased (141), changes indicative of a decreased 



