KISS1 and Anxiety: However, in zebrafish, habenula Kiss1 neurons have been associated with the modulation of serotonin neurons, fear-like responses and aversive memory and learning (Ogawa et al., 2012, 2014; Lupton et al., 2017; Sivalingam et al., 2020) (see section “Fear- and Anxiety- Like Behaviors” for more details).