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 aim of the present study was to find out whether the metabotropic receptor 1 ( mGluR1 ) and group II mGluRs , localized in the striatum , are involved in antiparkinsonian - like effects in rats .
### Output Text:
The aim of the present study was to find out whether the metabotropic receptor 1 ( mGluR1 ) and group II mGluRs , localized in the striatum , are involved in antiparkinsonian - like effects in rats . 