274881
In a model of an ion channel that has two gates ( an activation gate and an inactivation gate ) that must both be open for ions to be conducted through the channel , ' activation ' is the process of opening the activation gate , which occurs in response to the voltage inside the cell membrane ( the membrane potential ) becoming more positive with respect to the outside of the cell ( depolarization ) ; ' deactivation ' is the opposite process of the activation gate closing in response to the inside of the membrane becoming more negative ( repolarization ) . '
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities:  
Answer:
 None