CHAPTER 

 IX 



INFORMATION STORAGE IN NERVE CELLS 



Frank Morrell, M.D. 



Bi 



►EHAVIORAL observations have generally supported the 

 notion that (aside from genetic information) there are two quali- 

 tatively different forms of information storage in the nervous 

 system. So-called "recent" memory is made of particularly labile 

 stuff. A cerebral concussion produces an amnesia not only for the 

 injury itself but also for the events immediately leading up to the 

 injury, a circumstance about which many lawyers are painfully 

 aware. The impact of experience requires time for fixation. If 

 neural activity is interfered with during this fixation or con- 

 solidation period by electro-shock (13, 14, 53, 54), trauma (50), 

 severe cold (44), or rapid induction of ether or barbiturate anes- 

 thesia (1), subsequent recall of the experience may be seriously 

 compromised. For example, Duncan (13) and Gerard (14, 44) 

 have shown that rats or hamsters trained in an avoidance situation 

 or in maze-learning have a normal learning curve if a maximal 

 electro-shock is delivered four hours after each training session. 

 If the shock follows the training by one hour there is slight de- 

 terioration; at a fifteen minute interval there is major interference 

 with retention and at five minutes or less, learning is completely 

 prevented. Acute anoxia introduced at similar time intervals has 

 the same effect (53). Since all of the agencies known to produce 

 amnesia or loss of recent memory are also known to alter electrical 

 activity of the central nervous system, the mechanisms subserving 

 the initial stage of memory recording are inferred to be electrical 

 in nature. Other evidence supporting a clear distinction between 

 short-term and durable memory mechanisms is the finding that 



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