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: Protection against amphetamine - induced neurotoxicity toward striatal dopamine neurons in rodents by LY274614 , an excitatory amino acid antagonist .
### Output Text:
Protection against <span class="chemical">amphetamine</span> - induced neurotoxicity toward striatal <span class="chemical">dopamine</span> neurons in rodents by <span class="chemical">LY274614</span> , an excitatory <span class="chemical">amino acid</span> antagonist . 