… The thesis herein is that opponent processes begin early in drug taking, reflect changes in
brain reward and stress systems, and later form one of the major motivations for compulsivity …

… of cocaine subsequently exacerbates the subjective or behavioural response to low basal
DA, as would be expected from the opponent process … also self-administered more cocaine. …

… male and female rats when self-administered only at the highest two … properties in both
male and female rats in proestrus [33]. This suggests, as shown for other drugs such as cocaine …

… Briefly, an animal self-administered cocaine at a dose of 0.75 mg/kg per infusion by nose-poking
the active hole, accompanied by the switching-on of a light within the hole that served …

… a cocaineheroin mixture [87] and Fuchs and colleagues observed ABA but not AAB renewal
of cocaine … reinforcer by pairing it with intravenously self-administered morphine [119]. After …

… hydrogen-tartrate (Glentham, UK) was dissolved in sterile 0.9% physiological saline and
pH adjusted to 7.0 for a final training dose of 0.04 mg/kg free base, which was self-administered …

… The current study demonstrates that rats with extended access to self-administered cocaine
display not only an escalation of cocaine taking and later robust cocaine seeking, but also …

… Animals self-administered fentanyl in a manner consistent … Those negative calls were
associated with falling cocaine … those of cocaine SA, our findings with both fentanyl and cocaine …

… In the presence of laser stimulation, mice self-administered less cocaine and needed
more time to reach the maximum of 50 infusions of cocaine during daily 3-hour sessions. …

… Rats that self-administered cocaine for 10 days (1 mg/kg/infusion) showed similar patterns,
with enhancements in Nrf1, Tfb1, and Tomm20 (see Fig. 2b and Additional file 4). To …