3144
Neurons harvested from the forebrain of newborn rats were maintained under normal control conditions or exposed to either ketamine ( 10 micro M ) or ketamine plus L - carnitine ( an antioxidant ; 1 - 100 micro M ) for 24h , followed by a 24 - h withdrawal period .
 Chemical: ketamine; Chemical: ketamine; Chemical: L - carnitine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: ketamine; Chemical: ketamine; Chemical: L - carnitine