23063
P / Q - type voltage gated Ca ( 2 + ) channels play a vital role in presynaptic neurotransmitter release and thus play a role in action potential generation .
 Ca ( 2 + )
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Ca ( 2 + )