Addiction Flashcards
What are the common pathways activated by all drugs with addictive potential?
The pathway consists of a dopamine cell in the VTA (in the midbrain) synapse at the NAc (forebrain) release DA.
True or False: In order to understand a problem we must define it
True
True or False
The definition of a problem influences its treatment.
True
Compare addiction to another epidemic
In class we compare addiction to ___________.
How is it defined in traditional healthcare circles?
Diabetes (type II)
Definition: Diabetes is a chronic progressive disease involving poor of blood sugar (too much sugar in the blood)
How has the standard definition of T2DM lead to treatment?
Hint: What is the model that was created from the traditional definition of Diabetes?
Model:
Increase Blood Glucose is toxic to our tissues and this problem is due to Insulin Resistance. The cells do not take accept insulin which is needed to shuttle glucose into cells.
Treatment
Basically, for every health care problem, we give one pill or one procdure.
The treatment consists of Oral Agents and Injectetables
Metformin –> Decrease Glucose from liver
Sulfonylureas –> stimulate B cells in Pancreas –> Increase Insulin
Insulin
If lucky, provided a diet and exercise plan
Is the current treatment of T2DM effective?
Insulin Resistance is not the only reason why glucose is not going into cells.
Also, Blood glucose doesn’t rise until after the pancreas fail
What is a better description of the problem of T2DM and how would this new understanding of the problem change the treatment?
In this model, we do not focus on only blood glucose but total glucose, and not insulin resistance –> Hyperinsulinemia (too much insulin)
The excess glucose is converted to fat (denovolipogenesis); primary by the liver
Treatment
The only one that works is Metformin ( decrease Glucose from the liver)
provided Sulfonylureas and Insulin are a poor solutions
How do we define addicition?
A chronic progressive relapsing disease
Are there parallels between T2DM and addiction in terms of definitions and approaches to treatments?
Addiction and Diabetes have high relapsing rates.
Also, eating is behavior, and taking drugs is behavior so you have the controlled to stop the continuous usage.
What can we learn from one of these problems about the other?
How do we find a solution to the problem?
We figure out that in the one epidermic we can use that knowledge to trust the addiction epidemic.
What are the common ways of describing addiction?
Compulsive drug use regardless of the detrimental effects of the behavior on various aspects of health and life.
Again, words matter – why do we use the term relapse for addiction but not other common healthcare issues?
The struggle and try to solve the problem and return back to the usage of the drug.
What factors influence the likelihood of developing addiction (does this differ from that of T2DM?)
Environment
Chaotic home and abuse
Parent’s use and attitudes
Peer influences
Community attitudes
Poor school achievement
Biology/genes
Genetics
Gender
Mental disorders
Drugs
Route of adminsitarion
Effect of the drug itself
Early use
Availability
Cost
What are some of the neuroadaptations described consequent to repeat drug exposure?
Decrements in prefrontal cortical functioning
The anatomical shift in the dominant pathways of DA signaling VTA –>NAc
SN–> Straitum
Increased DA release from drug cue, increasing value
Molecular changes in extended reward circuit
Adaptations in brain stress system
What is the Reward Pathway and how did we find it?
This is done in an experiment on both humans and rats
What does dopamine release in the nucleus accumbens actually signal?
Dopamine is signaling motivated behavior.
Be familiar with the various functional circuits that are relevant to the development of addiction.
The prefrontal cortex is the thoughtful pathways to go and stop
The striatal pathways are the goal-directed behavior
The external context contain the memory –> which weighs in on your decission
Internal context –> consit of the insula check out your internal state
What are the Blunted response displayed by most long term users ?
Midbrain to Forebrain DA signals shift in favor of more rigid habitual responses
How does the prefrontal circuit and LTP play into the valuation of drug rewards compared to another reward?
Dopamine performs the cellular modification, The D1R, and GLUN1-NMDAR will be release by dimerized. NMDA receptor moves toward the spine and set at the glutamate synapse and drive LTP
How does dopamine release in PFC drive craving?
In the PFC (sub-regions for drive/motivation) with excess DA release associated with chronic drug use, Ca2+ activated K channels become disabled leading to increase excitability which causes the craving.
Where do choice and decision-making fit into addiction? Which part of the brain influences these functions?
Happens in the Pre Frontal Cortex and things to consider which making decision is the
value of the reward
relative value compared to other rewards
timing of available rewards
probability of actually getting available rewards
the effort required for possible rewards
Risk of behavior necessary
How does the consistent finding of a drug-induced decrease in expression of dopamine receptors relate to the concept of hypofrontality ion addiction?
How do progressive changes in the function of relevant neural circuits with addiction relate to our understanding of the behaviors commonly associated with someone suffering a substance use disorder?
