BBH 451 Exam 2 Review Questions and
Correct Answers
Addiction ✅State in which someone is afflicted with obsessive thought about drug
used and overcome by compulsive urges to use a drug.
Dependence ✅Indicatve of a state in which someone's body has adapted to the
presence of a drug to the extent that when the drug is removed, their body is thrown into
disequilibrium.
Addiction vs. Dependence ✅Addiction is more like a thought overcome with
compulsive urges while dependence is when the drug is removed from the body it goes
into disequilibrium.
Although physical dependence on a drug often coincides with addiction, it doesn't have
to (some drugs don't cause physical addiction).
Natural Rewards ✅Natural pleasures such as drinking water when thirsty, eating a
delicious meal, having sex. The brain finds this activities rewarding because are things
that make us survives and sex is necessary for propagation. These are all biological
events that makes us feel good so we can do it again. Natural rewards because they
are natural part of life.
Dopamine and Brain Reward Circuitry ✅The reward system involves a collection of
structures in the brain, but two of the major components are:
-Ventral termental area (VTA)
-nucleus accumbens
The VTA contains large numbers of dopamine neurons, which extend to the VTA.
Activation of mesolimbic pathway ✅When someone uses an addictive drug, neurons in
the VTA send dopamine to the nucleus accumbens through the mesolimbic dopamine
pathway, which cause dopamine levels in the nucleus accumbens to rise.
Dopamine responsible for creating pleasure? ✅Researchers do not necessarily
believe the dopamine signaling is responsible creating the feeling of pleasure we get
when we do something that is rewarding. There are a few reasons why they believe
this:
1. The aversive events also have been linked to rising dopamine levels in the nucleus
accumbens.
,2. The mesolimbic dopamine pathway is often activated before a drug is used, or upon
exposure to stimuli that someone has learned to associate with a pleasurable
experience.
Pleasure vs. other roles for dopamine ✅Researchers propose other functions for
dopamine that is released during rewarding experiences. Some evidence suggests that
dopamine signaling may be involved with the formation of strong memories that are
linked to the rewarding event. The memories can act as signposts that help to lead the
brain back to pleasurable experiences it achieved in the past.
For example, in the case of addiction, these memories become extremely powerful and
can linger for months, years, or even decades.
Hedonia hypothesis ✅Dopamine is considered the pleasure neurotransmitter in the
nucleus accumbens and is activated by many different pleasing rewards, like, food,
drugs, and cognitive rewards. This hypothesis suggests that dopamine mediates the
positive reinforcing effects of different reward stimuli, which could cause certain
behaviors to reoccur in the presence of these rewarding stimuli.
Incentive salience hypothesis ✅The role of dopamine is to mediate the "wanting"
component of the reward composite construct, which contains "wanting," "learning," and
"liking". The incentive salience is a cognitive process that confers an attribute of "desire"
or "want," which includes a motivational component, to a rewarding stimulus. The
"wanting" of incentive salience differs from "liking" in the sense that pleasing is the
pleasure that is immediately obtained from the acquisition or consumption of a
rewarding stimulus. The "wanting" of incentive salience serves as a "motivational
magnet" for a rewarding stimulus that makes it a desirable and attractive target,
transforming it from a mere sensory experience into something that draws attention,
induces rapprochement, and makes it sought after, which means that dopamine is
necessary for the "wanting" incentives but not for "liking" it or learning from it.
Reward prediction error models- reward learning hypothesis ✅Dopamine signals
between different neurons play a role in reward learning. The reward-prediction error
can be calculated by the pauses and bursts of dopaminergic activity in the midbrain,
which can be used as a teaching point in intermittent learning
Activation-sensorimotor hypothesis ✅This hypothesis states that dopamine is what
causes us to proceed and act on anything that motivates us. When you do something,
you want to do that you are using the DA system, which includes the ventral tegmental
area and the nucleus accumbens. These two structures combined hold and release the
neurotransmitter dopamine.
Increased sensitivity of brain reward circuitry that accompanies drug use ✅Frequent
exposure to an addictive drug cause the brain's reward circuity to become more
sensitive to stimuli associated with a drug (smell, places where someone did it). It
occurs because dopamine formes strong memories to those stimuli. And when exposed
, to these stimuli the brain immediately recognizes them and responds by initiating a
motivated state to obtain the drug.
For example, someone who smoke and tries to quit, before smoking it she din't find the
smell appealing. However now that she's trying to quit if she catches the scent her
craving for a cigarette will begin. The scent acts a strong trigger for her now hyper-
sensitive reward system. Thus smelling the cigarette beings a neurobiological process
that causes her to want to seek out a cigarette with the same fervor that a person who is
extremely thirsty might seek out a drink of water.
Tolerance ✅Consist of the progressive loss of the effects of a drug due to its repeated
use over time, which forces to increase the doses to recover the initial effect. The
greater one's exposure to an addictive drug is, the quicker their brain reward circuitry
will become ultra-sensitive to that drug.
Behavioral Tolerance ✅We become accustomed to the effects of the drug and we can
tolerate them much more capably.
Homeostasis ✅The tendency of a physiological system to move toward a state of
equilibrium.
Pharmacokinetic Tolerance ✅Is the type of tolerance induced by the change in rates of
enzyme metabolism. These changes help the body maintain homeostasis by ridding it
of a foreign substance, at the same time influencing the drug's in a way that it has less
of an effect on the individual. (Also called metabolic tolerance) because is based on
changes in rates of enzyme metabolism.
For example, when someone drinks alcohol, the enzymes metabolize some portion of
the alcohol we drink before it even enters your bloodstream, keeping it from being able
to interact with receptors in your brain. Thus, one way your body works to get alcohol
out of it is by increasing levels of alcohol dehydrogenases (enzymes). And that makes
less alcohol available to act in the body and it also gets more of it out of it more quickly.
That is why the individual has to take more alcohol to get the amount of it to the brain
that they have become used to.
Pharmacodynamic Tolerance ✅Occurs due to changes in the way interact with their
receptors. These changes are typically undertaken in an attempt to regulate levels of
neurotransmitter activity and to maintain homeostasis. Receptor up-regulation and
down-regulation.
For example, when someone drinks alcohol its act to increase activity at receptor for the
neurotransmitters GABA. Thus, after consuming alcohol repeatedly the brain recognize
the levels of GABA activity have gotten higher than it is accustomed to. So the brain
down-regulates the GABA receptor, causing fewer receptors to be available for GABA
to act at and thus reducing GABA activity in the brain.
