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: This was evident only when a sensory component was involved in the induction of plasticity , indicating that cerebellar sensory processing function is involved in the resurgence of M1 plasticity .
### Output Text:
This was evident only when a sensory component was involved in the induction of plasticity , indicating that cerebellar sensory processing function is involved in the resurgence of M1 plasticity . 