(Damseh et al., 2015). In addition, knockout of Asct1 in mice results in a significant decrease in brain glycine levels, deficits in glycine neurotransmission and a hyperekplexia-like phenotype. The clinical and pre-clinical phenotypes resulting from genetic variation in the cellular mechanisms that mediate l-serine transport in the brain fit with the finding that SERINC2 SNPs are associated with alcohol dependence. In particular, variation in SERINC2 may likely alter inhibitory glycine neurotransmission as well as excitatory glutamate neurotransmission that would be consistent with hyperexcitability and negative affect during alcohol abstinence or drug seeking and craving during protracted abstinence.
