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 contrast , there was a decrease in NADPH - d neuron number in the substantia nigra , pars compacta in both haloperidol - treated and L - NOARG - treated animals .
### Output Text:
In contrast , there was a decrease in <span class="chemical">NADPH</span> - d neuron number in the substantia nigra , pars compacta in both <span class="chemical">haloperidol</span> - treated and <span class="chemical">L - NOARG</span> - treated animals . 