RLN3 and Anxiety: While research over the last two decades has implicated the relaxin-3/RXFP3 system in a wide variety of functions, including modulation of stress, anxiety, foraging, and addictive and social behaviors (see Ma et al., 2017b; Olucha-Bordonau et al., 2018), for this review we examined the evidence for a specific role of NI transmitter systems, particularly relaxin-3/RXFP3, in relaying stress- and arousal-related signaling to higher neural centers associated with memory formation and retrieval.