Neurons permanent changes

If the change in cortical electrical characteristics is permanent, why don t seizures occur all the time This is probably because the occurrence of an individual seizure depends upon an interplay of environmental and internal brain factors which from time to time result in loss of the normal mechanisms that contain and control abnormal neuronal firing. Some common factors are sleep loss and fatigue, but it is impossible to determine what sets off a particular seizure in most patients. 

To be useful for more than a few minutes stored information must be transferred from the temporary to more permanent forms. We know that even temporary memory depends upon chemical changes in synapses. Long-term memory involves both stable chemical changes and also changes in the physical connections between neurons. Before discussing these... 

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