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: METHODS : Neonatal rats were treated with the tricyclic antidepressant clomipramine or vehicle between days 9 and 16 twice daily and behaviorally tested in adulthood .
### Output Text:
METHODS : Neonatal rats were treated with the tricyclic <span class="chemical">antidepressant</span> <span class="chemical">clomipramine</span> or vehicle between days 9 and 16 twice daily and behaviorally tested in adulthood . 