32 Motivation

Question 1

Define motivation.

Answer 1

motivation is a construct used to explain variability and flexibility in behavioral output that is attributable, not only to external, but internal states as well

Question 2

Differentiate between appetitively motivated behaviors and aversively motivated behaviors.

Answer 2

appetitively motivated behaviors have as their goal the attainment of desired objects/circumstances; aversively motivated behaviors seek to prevent or terminate negative stimuli or events

Question 3

What is the difference between reinforcement and reward?

Answer 3

reward has an additional subjective emotional experience that can accompany positive reinforcement

Question 4

What region of the basal ganglia handles input?

Answer 4

normally the striatum consisting of the caudate and the putamen

Question 5

Where do inputs to the basal ganglia come from and what neurotransmitter do these prospective areas use?

Answer 5

cortical inputs are glutamate encoded, inputs from the mesencephalon are in coded with dopamine, within the basal ganglia, opioid peptides are important for reward systems

Question 6

Output from the basal ganglia is encoded with which neurotransmitter?

Answer 6

GABA, transmission from the striatum is GABAergic

Question 7

What is important regarding the organization of cortical inputs to the basal ganglia as well as the organization of the basal ganglia nuclei?

Answer 7

incoming information is topographically organized and this information connects to specific places in the basal ganglia that have corresponding specific functions

Question 8

With in the basal ganglia circuitry, where do connections go (nuclei that are part of the circuitry) before they meet the in the thalamus?

Answer 8

sub thalamic nucleus and the pars compacta/reticulata, after these nuclei there are also connections to the cerebellum and brainstem (direct) that were not emphasized in the this lecture

Question 9

Where does input from the basal ganglia circuitry head from the thalamus?

Answer 9

back to the cortex, but to different places than the information originated; these areas include cortical areas involved in motor planning

Question 10

Where within the striatum is the nucleus accumbens relatively located.

Answer 10

ventral and medial along the sides of the septum

Question 11

What are the inputs for the nucleus accumbens?

Answer 11

prefrontal cortex (emotional regulation), amygdala (affect) and hippocampus (tying information together for declarative memory)

Question 12

Inputs to the nucleus accumbens use what neurotransmitter?

Answer 12

glutamate and dopamine

Question 13

Where do tracts from the nucleus accumbens project to?

Answer 13

ventral palladium and then the mediodorsal thalamus (completing the coritco-striato-pallido-thalamic tract)

Question 14

Ascending dopamine pathways from this brain area innervate the striatum, including the nucleus accumbens.

Answer 14

ventral segmental area (near to the substantia nigra)

Question 15

Name the predominant cell type of the striatum and its notable characteristics.

Answer 15

medium-spiny neuron is specialized in anatomical integration and uses GABA transmitter; stratal medium spiny output neurons specifically integrate multiple complex neurochemically specified inputs (glutamate, opioid and dopamine messaging)

Question 16

The CSPT loop through the nucleus accumbens appears to specialized for _________ relevant information. (what type of specialized information does this area manage)

Answer 16

motivationally relevant information

Question 17

Name two commonly used chemical entities that are used in reward and reinforcement.

Answer 17

dopamine and opioids (electrical stimulation of dopamine-rich brain regions is highly rewarding while pharmacological blockade of dopamine receptors blunts the brain stimulation-reward)

Question 18

What is the consequence of experiments that show animals with dopamine receptor blockade does not reduce feeding hungry rats?

Answer 18

encourages the concept that there are two separate pathways for “wanting” and “liking”

Question 19

Which neurotransmitters are for pathways involved in “wanting” vs. “liking”

Answer 19

dopamine for wanting (identifying salient reinforcers and pursuing them), opioids for liking (the subjective emotional experience of pleasure upon interacting with a reinforcer)

Question 20

Under what circumstances is dopamine released that elucidate its role in “wanting” as well as learning about rewards?

Answer 20

the first time an organism experiences a new primary reward, when observing a stimuli that reliably predicts an expected reward and when a previously experienced reward is better than predicted (dopamine is released on the nucleus accumbens from the ventral segmental area)

Question 21

Dopamine acts as a reward “teaching” signal that helps organisms learn what

Answer 21

how to get the reward, which is different from experiencing the actual reward (opioid linked)

Question 22

What are the components of the mesolimbic system

Answer 22

dopamine projections from the VTA to the nucleus accumbens which are hypothesized to play a crucial role in wanting and also reward-learning

Question 23

What system is involved in the hedonic experience of reward?

Answer 23

endogenous opioid system

Question 24

What is thought to cause excessive impulsivity?

Answer 24

impaired function of PFC inhibitory control

Question 25

Compulsivity is thought to result from a shift from ______ ______ motor circuits to an emphasis on ___ ___ control.

Answer 25

shift from prefrontal-accumbens motor circuits to an emphasis on dorsal stratal control, the dorsal striatum is thought mediate compulsive habits

Question 26

What role does impulsive tendency play a role in addiction?

Answer 26

impulsive behavior is linked to propensity to relapse

Question 27

How do distinct theories on addiction interact.

Answer 27

they describe different parts of the addiction cycle

Question 28

What nucleus is considered the link between the limbic system and the motor system?

Answer 28

nucleus accumbens

Question 29

What is tolerance

Answer 29

progressively diminished physiological response to a drug with repeated drug exposure, often defined operationally as a rightward shift in the dose-effect function

Question 30

Describe how the reward-based and withdrawal based theories of addiction apply to our knowledge of addiction

Answer 30

dopamine codes for the affective experience of reward (describe the euphoria of drugs); primary motivation is the desire to avoid unpleasant withdrawal symptoms by self-medication; counteradaption are hypothesized to produce drug tolerance and dependence