HOMER1 and heroin dependence: Opioids and their withdrawal alter Homer1 gene products within the PFC and AMY (Ammon et al., 2003; Kuntz et al., 2008) and recently, polymorphisms in Homer1, as well as changes in striatal and AMY Homer1 mRNA expression, were reported in post-mortem studies of heroin addicts (Okvist et al., 2011; Jacobs et al., 2012).