While the recent use of heroin was associated with enhanced Homer 1b/c—dynamin-3 interaction, both PSD proteins were significantly increased irrespective of blood morphine levels suggesting persistent disturbance of the excitatory synapse than only a rapid dynamic modulation due to the immediate pharmacological action of the drug. Enhanced Homer 1 b/c protein in the lateral amygdala was also evident in cocaine users emphasizing the important upregulation of the scaffolding protein in association with both psychostimulant and opiate drugs. Despite the critical role of Homer 1b/c and dynamin-3 in synaptic plasticity, no data are currently available in regard to dynamin-3's potential role in addiction and only limited investigations have directly evaluated amygdala Homer regulation in relation to behavior. To date, studies have examined either transgenic animals with a global developmental knockout of Homer 1 or have focused on manipulating Homer specifically in the nucleus accumbens (21, 46, 47). Such studies, based on locomotor sensitization as the behavioral indicator of addiction sensitivity, have led to the speculation that overexpression of Homer reduces addiction vulnerability (21, 46, 47). However, no animal investigation has evaluated
