“…In the few studies conducted thus far, several molecular targets have been identified in various behavioral paradigms across SOA classes using C. elegans (Engleman et al, 2016). Thus far, it appears that genes involved in monoamine neurotransmission mediate at least some behaviors induced by each SOA (Bettinger and McIntire, 2004; Lee et al, 2009; Ward et al, 2009; Musselman et al, 2012; Sellings et al, 2013; Topper et al, 2014; Matsuura and Urushihata, 2015). In particular, mutation of the gene coding for tyrosine hydroxylase ( cat-2 ) reduced or inhibited SOA-induced behaviors for each SOA of abuse (Bettinger and McIntire, 2004; Musselman et al, 2012; Matsuura and Urushihata, 2015).…”