14275
The role of other PDE families in synaptic plasticity has not yet been investigated , and this area promises to advance our understanding of cyclic nucleotide signalling in synaptic plasticity in the future .
 Chemical: cyclic nucleotide
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: cyclic nucleotide