1. Opiate and Nicotine Addiction: Involvement of cAMP Response Element Binding Protein (CREB) Matt Wolfe E-mail: mdw204@psu.edu

2. Addiction is a Disease? Addiction = compulsive drug craving and administration despite horrendous adverse consequences. Addiction = compulsive drug craving and administration despite horrendous adverse consequences. All addictive drugs seem to follow the “final common pathway” model. This states that, despite different molecular targets, all result in an increased release and dysregulation of synaptic dopamine. All addictive drugs seem to follow the “final common pathway” model. This states that, despite different molecular targets, all result in an increased release and dysregulation of synaptic dopamine. –Ventral tegmental area and the nucleus accumbens Los Angeles County Jail and New York City Rikers Island Prison. Los Angeles County Jail and New York City Rikers Island Prison.

3. Common Terms Associated with Drug Use Tolerance: The need for an increasing dose of opiate to achieve the same effect. Sensitization: An increasing effect achieved in response to a constant dose of opiate. Dependence: Altered physiological state produced by repeated drug administration  Cessation leads to a withdrawal syndrome.

4. CREB Transcription factor Transcription factor –cAMP stimulates its activation domain Phosphorylated CREB protein activates transcription by binding to the CRE which is near the genes induced by cAMP. Phosphorylated CREB protein activates transcription by binding to the CRE which is near the genes induced by cAMP. Similar to signal transducers and activators of transcription (STAT) protein Similar to signal transducers and activators of transcription (STAT) protein

5. Different requirements for cAMP response element binding protein in positive and negative reinforcing properties of drugs of abuse. By: Carrie L. Walters and Julie A blendy The Journal of Neuroscience (2001) Examined the role of final common mediators, such as CREB in the addiction process Examined the role of final common mediators, such as CREB in the addiction process Physical dependences alters signal transduction Physical dependences alters signal transduction –G-proteins, adenylate cyclase, protein kinase A and its target CREB CREB may affect positive and negative reinforcing properties of drugs CREB may affect positive and negative reinforcing properties of drugs CREB is critical for the manifestation of the physical signs of opiate withdrawal, but its role is not known CREB is critical for the manifestation of the physical signs of opiate withdrawal, but its role is not known

7. The Experiment In both the locus coeruleus and nucleus accumbens, the cAMP pathway was upregulated after chronic morphine In both the locus coeruleus and nucleus accumbens, the cAMP pathway was upregulated after chronic morphine To investigate the role of CREB behavior in drug seeking and reinstatement, the authors examined the sensitization to the locomotor effects induced by repeated cocaine administration in CREB  mutant mice. To investigate the role of CREB behavior in drug seeking and reinstatement, the authors examined the sensitization to the locomotor effects induced by repeated cocaine administration in CREB  mutant mice. Mutants have decreased CREB binding Mutants have decreased CREB binding

8. Conditioned place preference Animals subcutaneously implanted with one morphine pellet to induce dependence Animals subcutaneously implanted with one morphine pellet to induce dependence Preconditioning phase: Placed in one side of box and allowed to roam freely, determine side biases of the mice Preconditioning phase: Placed in one side of box and allowed to roam freely, determine side biases of the mice Conditioning Phase: 8 days, one group received saline on both sides of box, other group received morphine on one side and saline on opposite Conditioning Phase: 8 days, one group received saline on both sides of box, other group received morphine on one side and saline on opposite Testing Phase: Test day, all animals receive saline injections and allowed to roam freely on both sides of box. Time spent on each side recorded. Testing Phase: Test day, all animals receive saline injections and allowed to roam freely on both sides of box. Time spent on each side recorded.

9. Results Mutant mice do not exhibit morphine- conditioned place preference Mutant mice do not exhibit morphine- conditioned place preference Wild-type mice administered morphine prefer the side paired with morphine Wild-type mice administered morphine prefer the side paired with morphine * p < 0.05 from saline group * p < 0.05 from saline group

10. Conclusion CREB deficient mice do not respond to the reinforcing properties of morphine in a conditioned place preference paradigm. CREB deficient mice do not respond to the reinforcing properties of morphine in a conditioned place preference paradigm. Maybe a possible genetic link Maybe a possible genetic link Also, the rewarding and aversive properties of drugs of abuse (morphine) can be separated genetically Also, the rewarding and aversive properties of drugs of abuse (morphine) can be separated genetically

11. But, opioids aren’t the only addictive drugs… Tobacco Tobacco Each year 1 million people attempt to quit Each year 1 million people attempt to quit Only 15% do so for a full year Only 15% do so for a full year Genetic vs. Development factors Genetic vs. Development factors Twin Studies Twin Studies CDC 2001 – smoking is the single greatest cause of preventable death in the U.S. CDC 2001 – smoking is the single greatest cause of preventable death in the U.S.

12. In vivo nicotine treatment regulates mesocorticolimbic CREB and ERK signaling in C57B1/6J mice By: Brunzell, D.H., Russell, D.S., and Picciotto, M. R. Journal of Neurochemistry (2003) CREB phosphorylation was reduced in the nucleus accumbens following chronic nicotine, consistent with previous reports that decreased accumbens CREB activity increases drug reinforcment. CREB phosphorylation was reduced in the nucleus accumbens following chronic nicotine, consistent with previous reports that decreased accumbens CREB activity increases drug reinforcment. Also, CREB phosphorylation was increased in the prefrontal cortex following chronic nicotine exposure and in the ventral tegmental area during withdrawal. Also, CREB phosphorylation was increased in the prefrontal cortex following chronic nicotine exposure and in the ventral tegmental area during withdrawal.

13. Experiment Acute Study: Mice given either 200  g/mL nicotine in 2% saccharin or saccharin alone, drank within two minutes, brains harvested 1.3 hours later Acute Study: Mice given either 200  g/mL nicotine in 2% saccharin or saccharin alone, drank within two minutes, brains harvested 1.3 hours later Chronic Treatment and Withdrawal Study: Mice given similar doses for 28-30 days, brains harvested Chronic Treatment and Withdrawal Study: Mice given similar doses for 28-30 days, brains harvested –Withdrawal group: Nicotine solution replaced with a 2% saccharin solution 24 hours prior to decapitation

14. Results Nucleus Accumbens (NAC): acute nicotine exposure increased CREB levels significantly Nucleus Accumbens (NAC): acute nicotine exposure increased CREB levels significantly –Chronic nicotine also resulted in an increase in total CREB, but also a decrease in pCREB –Levels of CREB were still elevated following 24 hours of withdrawal Decrease in ratio of pCREB/CREB in the NAC following chronic nicotine exposure is consistent with studies that have shown that this decrease contributes to drug reinforcement. Decrease in ratio of pCREB/CREB in the NAC following chronic nicotine exposure is consistent with studies that have shown that this decrease contributes to drug reinforcement.

16. Conclusions: Increased CREB activity counteracts drug reinforcement Increased CREB activity counteracts drug reinforcement CREB may be dependent on ERK activation CREB may be dependent on ERK activation Further studies needed to define the specific roles of ERK and CREB activation in behaviors surrounding nicotine addiction Further studies needed to define the specific roles of ERK and CREB activation in behaviors surrounding nicotine addiction

17. Importance Need to understand the mechanisms of addiction to provide better treatment and maintenance of a healthy lifestyle Need to understand the mechanisms of addiction to provide better treatment and maintenance of a healthy lifestyle Why is drug abuse considered more of a crime than an illness? Why is drug abuse considered more of a crime than an illness?

18. References Google Images: Keith Richards Accessed April 1, 2003 Google Images: Keith Richards Accessed April 1, 2003Keith RichardsKeith Richards Brunzell, D.H., Russell, D.S., and Picciotto, M. R. (2003) In vivo nicotine treatment regulates mesocorticolimbic CREB and ERK signaling in C57B1/6J mice. Journal of Neurochemistry, 84, 1431-1441. Brunzell, D.H., Russell, D.S., and Picciotto, M. R. (2003) In vivo nicotine treatment regulates mesocorticolimbic CREB and ERK signaling in C57B1/6J mice. Journal of Neurochemistry, 84, 1431-1441. Halpern, J.H. (2002) Addiction is a disease. Psychiatric Times, XIX, issue 10. Halpern, J.H. (2002) Addiction is a disease. Psychiatric Times, XIX, issue 10. Walters, C.L., and Blendy, J.A. (2001) Different requirements for cAMP response element binding protein in postitive and negative reinforcing properties of drugs of abuse. The Journal of Neuroscience, 23, 9438-9444. Walters, C.L., and Blendy, J.A. (2001) Different requirements for cAMP response element binding protein in postitive and negative reinforcing properties of drugs of abuse. The Journal of Neuroscience, 23, 9438-9444. Becker, W. M., Kleinsmith, L.J., and Hardin, J. The World of the Cell—4 th ed. Addison Wesley Longman, Inc., 2000. Becker, W. M., Kleinsmith, L.J., and Hardin, J. The World of the Cell—4 th ed. Addison Wesley Longman, Inc., 2000.