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: METHODS : Male Wistar rats received each dose of the alpha ( 2 ) - adrenoceptor antagonist yohimbine ( 0 . 25 - 1 . 0mg / kg ) , the 5 - HT ( 2C ) receptor agonist m - chlorophenylpiperazine ( mCPP , 0 . 5 - 2 . 0mg / kg ) or the GABA ( A ) inverse receptor agonist pentylenetetrazole ( PTZ , 3 - 30mg / kg ) and were subsequently tested in either LES or FPS .
### Output Text:
METHODS : Male Wistar rats received each dose of the alpha ( 2 ) - adrenoceptor antagonist <span class="chemical">yohimbine</span> ( 0 . 25 - 1 . 0mg / kg ) , the <span class="chemical">5 - HT</span> ( 2C ) receptor agonist <span class="chemical">m - chlorophenylpiperazine</span> ( <span class="chemical">mCPP</span> , 0 . 5 - 2 . 0mg / kg ) or the <span class="chemical">GABA</span> ( A ) inverse receptor agonist <span class="chemical">pentylenetetrazole</span> ( <span class="chemical">PTZ</span> , 3 - 30mg / kg ) and were subsequently tested in either LES or FPS . 