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: Two mouse lines selected for differential sensitivities to beta - carboline - induced seizures are also differentially sensitive to various pharmacological effects of other GABA ( A ) receptor ligands .
### Output Text:
Two mouse lines selected for differential sensitivities to <span class="chemical">beta - carboline</span> - induced seizures are also differentially sensitive to various pharmacological effects of other <span class="chemical">GABA</span> ( A ) receptor ligands . 