state the replicate line-pair examined, which has forced us to state HAD vs. LAD differences in many instances rather than the preferred HAD1 vs. LAD1 or HAD2 vs. LAD2 distinctions. Also, in general only the DA, NE, 5-HT and opioid systems have been examined in all four lines described in Table 3. Table 3 also makes it clear that different laboratories have focused on different (a) brains regions and/or (b) parameters examined (e.g., findings on protein and mRNA levels are very rarely reported in the same paper). Nevertheless, substantial progress has been made on innate differences in mesolimbic regions (i.e., VTA and Acb) which has been extended to other regions within the mesocorticolimbic and extended amygdala systems (i.e., PFC, CeA and BLA) as well.
