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: In conclusion , treatment with BMCs can prevent the development of chronic seizures , reduce neuronal loss , and influence the reorganization of the hippocampal neuronal network .
### Output Text:
In conclusion , treatment with BMCs can prevent the development of chronic seizures , reduce neuronal loss , and influence the reorganization of the hippocampal neuronal network . 