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: The present experimental results indicated that peptidergic stimulation of the LC resulted in a NE - mediated inhibition of cerebellar Purkinje cells located at terminals of the ceruleo - cerebellar pathway .
### Output Text:
The present experimental results indicated that peptidergic stimulation of the LC resulted in a NE - mediated inhibition of cerebellar Purkinje cells located at terminals of the ceruleo - cerebellar pathway . 