Amygdala and Bed Nucleus of the Stria Terminalis Circuitry: Implications for Addiction-Related Behaviors.

Amygdala and Bed Nucleus of the Stria Terminalis Circuitry: Implications for addiction-related behaviors.

Neuropharmacology. 2013 Jun 7;
Stamatakis AM, Sparta DR, Jennings JH, McElligott ZA, Decot H, Stuber GD

Complex motivated behavioral processes, such as those that can go awry following substance abuse and other neuropsychiatric disorders, are mediated by a distributive network of neurons that reside throughout the brain. Neural circuits within the amygdala regions, such as the basolateral amygdala (BLA), and downstream targets such as the bed nucleus of the stria terminalis (BNST), are critical neuroanatomical structures for orchestrating emotional behavioral responses that may influence motivated actions such as the reinstatement of drug seeking behavior. Here, we review the functional neurocircuitry of the BLA and the BNST, and discuss how these circuits may guide maladaptive behavioral processes such as those seen in addiction. Thus, further study of the functional connectivity within these brain regions and others may provide insight for the development of new treatment strategies for substance use disorders. HubMed – addiction


Transition from ‘model-based’ to ‘model-free’ behavioral control in addiction: involvement of the orbitofrontal cortex and dorsolateral striatum.

Neuropharmacology. 2013 Jun 7;
Lucantonio F, Caprioli D, Schoenbaum G

Cocaine addiction is a complex and multidimensional process involving a number of behavioral and neural forms of plasticity. The behavioral transition from voluntary drug use to compulsive drug taking may be explained at the neural level by drug-induced changes in function or interaction between a flexible planning system, associated with prefrontal cortical regions, and a rigid habit system, associated with the striatum. The dichotomy between these two systems is operationalized in computational theory by positing model-based and model-free learning mechanisms, the former relying on an “internal model” of the environment and the latter on pre-computed or cached values to control behavior. In this review, we will suggest that model-free and model-based learning mechanisms appear to be differentially affected, at least in the case of psychostimulants such as cocaine, with the former being enhanced while the latter are disrupted. As a result, the behavior of long-term drug users becomes less flexible and responsive to the desirability of expected outcomes and more habitual, based on the long history of reinforcement. To support our specific proposal, we will review recent neural and behavioral evidence on the effect of psychostimulant exposure on orbitofrontal and dorsolateral striatum structure and function. HubMed – addiction


“Media addiction” in a 10-year-old boy.

J Dev Behav Pediatr. 2013 Jun; 34(5): 375-8
Brown S, Scharf MA, Bustos C, Chavira D, Stein MT

: Bryan is a 10-year-old boy who is brought to his pediatrician by his parents with concerns about oppositional behaviors. Bryan’s parents report that he has always been hyperactive and oppositional since a very young age. He has been previously diagnosed with attention-deficit hyperactivity disorder and has been treated with appropriate stimulant medications for several years; however, despite this, his parents feel increasingly unable to manage his difficult behaviors. He refuses to do chores or follow through with household routines. He refuses to go to bed at night. His family feels unable to take him to public places because he “climbs all over everything.” At school, he acts up in class, is often disruptive, and requires close supervision by teachers. He was recently kicked off of the school bus. He has very few friends, and his parents state that other children do not enjoy to be around him.Bryan’s parents also report that he is “obsessed” with electronics. He spends most his free time watching TV and movies and playing computer games. He has a television in his bedroom because otherwise he “monopolizes” the family television. The family also owns several portable electronic devices that he frequently uses. Bryan insists on watching TV during meals and even that the TV stays on in an adjacent room while showering. He gets up early each morning and turns on the television. He refuses to leave the house unless he can take a portable screen device with him. His parents admit to difficulty placing limits on this behavior because they feel it is the only way to keep his other behaviors under control. His mother explains “it is our only pacifier” and that attempts to place restrictions are met with explosive tantrums and have thus been short lived. These efforts have also been impeded due to the habits of his parents and older sibling, who also enjoy spending a significant amount of time watching television. HubMed – addiction