19689
Preferentially expressed on presynaptic nerve terminals , the mGlu2 receptor negatively modulates glutamate and GABA release and is widely distributed in the brain .
 Chemical: glutamate; Chemical: GABA
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: glutamate, GABA 
Answer:
 Chemical: glutamate; Chemical: GABA