Neuroscience of addiction By Juuli Tuomi

Basic facts Alcohol –18 million Americans abuse Alcohol. 2.2 million of them are currently seeking treatment Smoking --In US, approximately 440,000 persons die per year of a cigarette smoking-attributable illness Opioid Dependency –Dependency has been growing rapidly: From 1990 to 2001, the number of people who used prescription painkillers recreationally for the first time grew by 335%. Over an 8-year period ( ): Admissions involving oxycodone rose 450% Admissions involving hydrocodone rose 170%

Research designed to determine changes in the brain that occur in conjunction with the development of addiction. At the present time, the research is primarily in rats. Nucleus Accumbens and Extended Amygdala — Forebrain structures involved in the rewarding effects of drugs of abuse. Composed of central nucleus of the amygdala, bed nucleus of the stria terminalis, and a transition zone in the medial part of the nucleus accumbens Corticotropin-Releasing Factor — “brain stress” neurotransmitter, 41 amino acid polypeptide that controls hormonal, sympathetic, and behavioral responses to stressors Transcription Factors — brain chemicals involved in the longterm neuroadaptive changes within neurocircuits associated with chronic administration of drugs of abuse. Transcription factors can gene expression Definition and key structures

DSM-IV definition of substance dependence Taking the substance in larger amounts or over the substance in larger amounts or over a longer period than intended Failing attempts to reduce or stop use Spending a great deal of time obtaining, using, and recovering from using the substance Giving up important activities in order to use the substance Continued use despite recognition of the negative side-effects (how much of this can be applied to animals?)

Addiction Vs. Dependence

Reward Transmitters Implicated in the Positive Motivational Effects of Drugs of Abuse Positive Hedonic Effects: Inc. Dopamine Inc. Opioid peptides Inc. GABA Inc. Glutamate Inc. Serotonin Negative hedonic Effects: Dec. Dopamine … “dysphoria” Dec. Opioid peptides... pain Dec. Serotonin … “dysphoria” Dec. GABA … anxiety, panic attacks

Protocol for Initiation of Lever Pressing for Oral Ethanol Self-Administration in the Rat

Neurochemical Changes Associated with the Drug Use, Dependence and Relapse

Summary- Neurocircuitry of Addiction Reward Circuit- nucleus accumbens and extended amygdala (bed nucleus of the stria terminalis and central nucleus of the amygdala) “Craving” Circuit- dorsal prefrontal cortex, basolateral amygdala “Compulsivity” Circuit- ventral striatum, ventral pallidum,medial thalamic- orbitofrontal cortical loop

Thank you for your attention!

References n%20ppt&source=web&cd=2&cad=rja&ved=0CDMQFjAB&url=http%3A %2F%2Fwww.ncsconline.org%2Fd_research%2Fstl%2Fdec06%2FAA ASJudicial%2520Dec06_Koob.ppt&ei=vezEUP2yGKOJ4gTFxYDABQ& usg=AFQjCNGhQ6NAmGGagxbXtO1RTo-KP2ZOsA on.pdf biw=1366&bih=643&tbm=isch&tbnid=y3ag8xBKq6jRZM:&imgrefurl=http ://batonrougecounseling.net/anger- addiction/&docid=PSbdgqVfwpqGYM&imgurl= ng.net/wp- content/uploads/2011/01/AddictionCycle.jpg&w=400&h=300&ei=e- zEUJKFNMbd4QTl7YGoAg&zoom=1&iact=hc&vpx=270&vpy=167&dur =487&hovh=194&hovw=259&tx=170&ty=63&sig= &page=1&tbnh=144&tbnw=187&start=0&ndsp=22&ved=1t:429,r:2, s:0,i:156 drug-addiction/section-iii-action-heroin-morphine/10-addiction-vs- dependencehttp:// drug-addiction/section-iii-action-heroin-morphine/10-addiction-vs- dependence