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: Daily treatment of cocaine increased [ ( 3 ) H ] norepinephrine uptake into the hippocampus .
### Output Text:
Daily treatment of <span class="chemical">cocaine</span> increased [ ( 3 ) H ] <span class="chemical">norepinephrine</span> uptake into the hippocampus . 