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: Given alone to any accumbal subregion , GR 55562 ( 0 . 1 - 10 microg / side ) or CP 93129 ( 0 . 1 - 10 microg / side ) did not change basal locomotor activity .
### Output Text:
Given alone to any accumbal subregion , <span class="chemical">GR 55562</span> ( 0 . 1 - 10 microg / side ) or <span class="chemical">CP 93129</span> ( 0 . 1 - 10 microg / side ) did not change basal locomotor activity . 