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 parallel , another neurochemical feature of depression - - astroglial dysfunction - - was unaffected in the cortex and the striatal levels of the astrocytic protein marker , glial fibrillary acidic protein , were only transiently increased at 3 days .
### Output Text:
In parallel , another neurochemical feature of depression - - astroglial dysfunction - - was unaffected in the cortex and the striatal levels of the astrocytic protein marker , glial fibrillary acidic protein , were only transiently increased at 3 days . 