Stress and Drug Abuse

1. Stress and Drug Abuse • Primary interaction of stress and drug abuse is relapse. • Can stress cause initiation of drug use/abuse?

2. Reinstatement Mediated relapse • following extinction of drug use, introduce a small • dose of drug or drug context. • results in addictive relapse

3. Stress Mediated relapse Stress can cause drug relapse in human and animals. Footshock following extinction causes relapse (as measured by drug seeking behavior) in rats. Humans report an increase in relapse when confronted with stressful situations. • In animal studies stress induced relapse has limitations. • It is context dependent. • Footshock must be applied in the lever box • The stress must be negative • Sexual stimulation (stress response equal to FS) does not induce relapse

7. Salient actions other than abuse drugs. (food, sex and just plain old brain stimulation)

8. Are Primed and Stress mediated relapse influenced by similar neurochemical phenomenology? DA antagonists DA1 (SCH-23390), DA2 (raclopride), and DA1+2 (flupenthixol decanoate)receptor antagonists all block primed relapse Foot Shock mediated relapse is only blocked by DA1+2 antagonist

9. Are Primed and Stress mediated relapse influenced by similar neurochemical phenomenology? • Systemic administration of a m-opiate receptor antagonist (naltrexone) inhibits heroin primed relapse, but not FS mediated relapse. CRF antagonist (a-H-CRF) decrease FS mediated relapse, but not heroin primed relapse

10. Cocaine Experience establishes control of midbrain Glu and DA by CRF: A role in stress-induced relapse to drug seeking. Wang et al. 2005

11. CRF injections into the BNST reinstate drug seeking behavior. • CRF injections into the VTA induce increases in locomotion as well as mesocorticolimbic DA activity. • Increased mesocorticolimbic DA activity is also observed with drug use and stress exposure. • AMPH • Cocaine • Morphine • Nicotine • Ethanol

12. http://learn.genetics.utah.edu/units/addiction/drugs/mouse.cfmhttp://learn.genetics.utah.edu/units/addiction/drugs/mouse.cfm

13. Rat Surgery and Manipulation Rats were fitted with a jugular catheter for cocaine/saline injection. Rats were fitted with guide cannulae directed towards the VTA or Substantia nigra for recording neurotransmitter activity or injection of pharmaceuticals. All cannulae were connected to a micropump, to allow infusion of drugs, and collection of ECF for analysis. CPu DA NAcc SN DA VTA

14. 50 50 Active 40 40 Lever Presses/Session (4 hours) 30 30 20 20 10 10 Inactive 0 0 Cocaine- Trained Cocaine- Naive Getting them addicted (Self-administration training). Rats pressed a lever for IV cocaine administration in an operant chamber over a 10 day period (4 hours of training each day). Controls were injected with saline via IV catheter of similar placement for a similar time period.

15. Extinction Session Active Lever injected only saline. Continued until fewer than 16 lever presses/session. This took 14-25 sessions. Withdrawal • Three groups of animals did not experience extinction. • They were assessed following self administration training: • either 1,7,or 21 days later. • (these animals will come later)

16. Footshock Paradigm A test was performed the night before the footshock administration to determine individual threshold levels of current necessary to induce freezing. 20 minute series of inescapable and unpredictable 0.5 second 0.3-0.6mA shock (depending on individual threshold level for freezing) every 40+30s. Following footshock, levers were returned to the box, and a light was illuminated above the lever.

17. Footshock Paradigm A test was performed the night before the footshock administration to determine individual threshold levels of current necessary to induce freezing. 20 minute series of inescapable and unpredictable 0.5 second 0.3-0.6mA shock (depending on individual threshold level for freezing) every 40+30s. Following footshock, levers were returned to the box, and a light was illuminated above the lever.

18. Footshock Paradigm A test was performed the night before the footshock administration to determine individual threshold levels of current necessary to induce freezing. 20 minute series of inescapable and unpredictable 0.5 second 0.3-0.6mA shock (depending on individual threshold level for freezing) every 40+30s. Following footshock, levers were returned to the box, and a light was illuminated above the lever.

19. Foot Shock effect on Reinstatement and VTA CRF release Over two hours following footshock and lever introduction, microdialysis samples were taken to measure VTA CRF release TTX (Na+ channel blocker) was given to one group to ensure that CRF increase was due to AP induced synaptic neurotransmission.

20. CeA ? BNST CRF ? ? VTA

21. Foot Shock effect on Reinstatement and VTA DA and Glu release Same methods as used previously, except that VTA DA and Glu were measured.

22. mPFC CeA ? BNST CRF Glu ? ? LDT/PPT VTA Glu

23. Effect of Foot Shock + a-H-CRF infusion into the VTA on Reinstatement and VTA DA and Glu release

24. Effect of Foot Shock + a-H-CRF infusion into the VTA on Reinstatement and VTA DA and Glu release

25. Effect of Foot Shock + a-H-CRF infusion into the SN on reinstatement and SN DA and Glu release. 1mM a-H-CRF 10mM a-H-CRF

26. Effect of Foot Shock + a-H-CRF infusion into the SN on reinstatement and SN DA and Glu release 1mM a-H-CRF 10mM a-H-CRF No effect of CRF in the SN!!!

27. Effect of Foot Shock + Glu antagonist (Kynurenic Acid) infusion into the VTA on reinstatement and DA and Glu release.

28. Effect of Foot Shock + Glu antagonist (Kynurenic Acid) infusion into the VTA on reinstatement and DA and Glu release.

29. Effect of CRF infusion into the VTA reinstatement behavior. with a-H-CRF and Kyn

30. Effect of withdrawal on CRF mediated VTA Glu release. Effects of a-H-CRF and TTX on CRF mediated VTA Glu release.

31. Takehome Messages • Stress induced relapse is: • mediated via CRF release into the VTA • onto Glutamate axon terminals • which potentiates DA release at the NAcc • and mPFC. • Additionally, relapse is blocked by injection of DA antagonists into the NAcc or mPFC.

32. CeA BNST CRF

33. CeA BNST CRF Stress

34. mPFC CeA BNST CRF Glu LDT/PPT Glu Stress

35. mPFC CeA BNST CRF Glu LDT/PPT Glu Stress VTA DA

36. mPFC CeA BNST CRF Glu LDT/PPT Glu NAcc Stress VTA DA