In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: 5 , 7 - DCKA injected bilaterally in a dose of 4 . 5 microg / 0 . 5 microl into the intermediate - caudal region of the striatum of rats not pretreated with haloperidol had no effect on the muscle tone .
### Output Text:
<span class="chemical">5 , 7 - DCKA</span> injected bilaterally in a dose of 4 . 5 microg / 0 . 5 microl into the intermediate - caudal region of the striatum of rats not pretreated with <span class="chemical">haloperidol</span> had no effect on the muscle tone . 