3050
The effects of dopamine and of dopamine D2 receptor blocker haloperidol on the activity of carotid chemoreceptors were studied in 24 anesthetized , paralyzed and artificially ventilated newborn kittens aged 0 - 17 days .
 GENE: dopamine D2 receptor
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: dopamine D2 receptor