Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:…(anandamide, AEA) and 2-arachidonoylglycerol (2-AG), which are known to modulate synaptic transmission throughout the brain (Zogopoulos et al., 2013).
mental Medicine and Surgery, Rome, Italy. or Brain Research/Fondazione . a), s.marinelli@ebri.it
Unlike other…
Category: