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: Overall these findings suggest that mGlu7 receptor activation can reverse motor dysfunction associated with reduced dopamine activity .
### Output Text:
Overall these findings suggest that mGlu7 receptor activation can reverse motor dysfunction associated with reduced <span class="chemical">dopamine</span> activity . 