15254
Notably , synthetic polycyclic cage compounds have served as scaffolds for novel voltage - gated calcium channel blockers , NMDA receptor antagonists , and sigma - receptor ligands - attractive targets in neurodegeneration .
 Chemical: calcium; Chemical: NMDA
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: calcium; Chemical: NMDA