11226
In order to assess whether caffeine and theophylline have the same potency and efficacy to reverse the impairment of motor function caused by acute or chronic interruption of striatal dopamine transmission , a comparison of their dose - response relationship was made in the acute model of haloperidol - induced catalepsy , and the chronic model of unilateral lesion of the dopamine nigrostriatal pathway with 6 - hydroxydopamine .
 Chemical: caffeine; Chemical: theophylline; Chemical: dopamine; Chemical: haloperidol; Chemical: dopamine; Chemical: 6 - hydroxydopamine
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: caffeine; Chemical: theophylline; Chemical: dopamine; Chemical: haloperidol; Chemical: dopamine; Chemical: 6 - hydroxydopamine