Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BPS > Karius: Neurophysiology of Addiction > Flashcards

Karius: Neurophysiology of Addiction Flashcards

1
Q

what is tolerance

A

-decrease in response to dose of drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What 2 things comminicate in the core of the reward/pleasure system?

A
  • the Ventral tegmental area (VTA)

- Nucleus Accumbens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the VTA?

A
  • major input to the pleasure/reward system

- sends dopamine to target neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where does the VTA receive excitatory input from?

A
  • the prefrontal cortex
  • Lateral hypothalamus
  • Laterodorsal tegmental nucleus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the PFC release?

A

-EAA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the lateral hypothalamus release?

A

-Orexin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does the laterodorsal tegmental N nucleus release?-

A

-Acetylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the VTA provide to the Nucleus accumbens and how does it do it?

A

-VTA provides dopaminergic input to the nucleus accumbens via the MEDIAN FOREBRAIN BUNDLE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the nucleus accumbens?

A
  • the third nucleus in the striatum
  • often referred to as the ventral striatum
  • has the same basic micro-circuitry as the others
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where does the Nucleus accumbens receive excitatory input from?

A
  • PFC
  • Amygdala
  • Hippocampus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where does the output from the NAc go to?

A
  • the PFC

- releases GABA onto the pre frontal cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Does the NAc also send GABAergic input BACK to the VTA?

A
  • yes

- tells the VTA that it’s had enough

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which cotransmitter is also released in the VTA?

A

-dynorphin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where do the pleasure/reward systems receive inputs from?

A

-multiple opioid paths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do opioid inputs do to the VTA?

A
  • inhibit a subset of GABAerigic interneurons

- this INCREASES the release of DA in the NAc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the “reward (pleasure) system” and how the following nuclei participate in producing pleasure

A
  • VTA: reveives inputs and releases DA in NAc to lead to feeling of pleasure
  • NAc: part of striatum. D1- activate direct; D3 inhibit indirect pathways. When active, GABA is released to produce pleasure
  • PFC: Receives input allowing pleasure from NAc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is input to the NAc mediated by?

A

-DA!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is DA’s effect in the NAc?

A

-inhibitory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

At this point, what does the core system of producing pleasure look like?

A
  • VTA releases DA onto the NAc which then decreases its GABA release onto the PFC
  • this leads to pleasure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What do NAc neurons do?

A

-release GABA onto their targets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

So then, what is the effect of DA release ?

A

-to decrease GABA release in the PFC and allow activity of the reward pathways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What 2 things are in that flow chart affecting the VTA?

A
  • PFC, Laterodorsal tegmental nucleus: releases EAA’s onto VTA
  • Lateral Hypothalamic nucleus: releases Orexin onto VTA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does the pathway look like for preventing pleasure?

A
  • PFC, Amygdala, Hippocampus: releases EAA onto NAc
  • NAc increases GABA output onto PFC
  • this leads to absence of pleasure
24
Q

So, how do the opioid produce pleasure?

A
  • activate VTA
  • VTA releases DA onto NAc
  • NAc releases less GABA
  • Pleasure happens
25
Q

Is the pleasure/reward system a positive feedback system?

A

-Unstable

26
Q

Describe DA in this lecture

A
  • released by VTA neurons whose axons terminate in the NA

- binds to D1, 2, 3 receptors (2 and 3 are inhibitory)

27
Q

Describe GABA in this lecture

A
  • released by NA neurons whose axons terminate in the PFC

- also fibers terminating in VTA from NA or interneurons within VTA

28
Q

Describe the opioids in this lecture

A

-major action: inhibit GABA interneuron in VTA….VTA releases more DA in NA…. intense feeling of pleasure (euphoria)

29
Q

So basically, how do we do to produce pleasure?

A
  • activate the VTA
  • inhibit the NAc
  • Less GABA inthe PFC
  • pleasure happens
30
Q

How doe we inhibit pleasure?

A
  • Acivate the NAc
  • more GABA in the PFC
  • prevent pleasure
31
Q

Where are the most prominent changes when we do some memory?

A

-at the synapses!

32
Q

What is long term potentiation?

A
  • a series of changes in the pre and post synaptic neurons of a synapse which leads to increased response tot he released NT
  • must last for hours after the stimulation
  • usually follows strong stimulation
  • triggers a series of biochemic events that change gene trascription and translation
  • permanently alter synaptic structure
33
Q

What is synaptic plasticity?

A
  • changes in the anatomy and physiology of synapses associated with learning
  • some changes are permanent, others more transient
34
Q

What is long term potentiation again?

A
  • increase in response to same stimulus
  • changes in both the pre and post synaptic neurons
  • Includes: increased NT release, increased post-synaptic responses due to changes in the receptors to which the NT binds
35
Q

How do Opiates work?

A
  • agonist at opioid receptors

- second messenger system (Gi)

36
Q

How does Cannabis work?

A

-CB-1 receptor, leads to DA release

37
Q

Which drugs activate GPCR’s?

A

-Opiates and Cannabis

38
Q

Which drugs alter ion channels?

A
  • Nicotine: agonist at nicotinic cholinergic receptors, influx of sodium
  • Ethanol/PCP: Antagonist at NMDA receptors (PCP is weak, but ethanol is allegedly pretty good at it)
39
Q

Which drugs interfere with re-uptake mechanisms?

A
  • CocaineL inhibit re uptake of DA, leads to increase in DA availability at synapes, similar effects on other monoamine system
  • Amphetamines: reversal of DA reuptake transporters
40
Q

How does ethanol activate the reward system?

A
  • activates the opioid inputs (particuluarly to the VTA)

- VTA releases DA onto NAc, that decreases GABA…. pleasure happens

41
Q

What does PCP and ethanol do to EAA inputs to the NAc?

A
  • disrupts them
  • stops the PFC, amygdala, hippocampus from releasing EAA
  • EAA can’t activate NAc
  • Low GABA to PFC
  • pleasure happens
42
Q

The PFC is working, will pleasure happen?

A

-yes, if PFC is NOT inhibited by GABA, pleasure seems to happen

43
Q

What agents will increase the activity of VTA DA neurons?

A
  • cocaine
  • amphetamines
  • cannabis
44
Q

What does Nicotine activate?

A

-Nicotinic AchR on VTA neurons and induces them to release DA

45
Q

What is the result of increasing the action of dopamine in the NAc?

A

-euphoria is produced

46
Q

What are the normal responses to pleasurable stimuli?

A
  • result of DA release in the nucleus accumbens
  • Goal: reinforce the occurrence of behaviors that are not necessarily immediately beneficial
  • the reward for these behaviors is pleasure
47
Q

How do the drugs of addiction, how do they work?

A
  • the vast majority of addictive drugs lead to an increase in the DA released within the nucleus accumbens
  • The release of DA is not proportional to the normal stimuli
  • this leads to euphoria or an exaggerated reward response to even mild stimuli
48
Q

How does INduction of CREB happens?

A
  • cAMP response element binding ptn

- Part of regulatory region in many genes: neuropeptides, enzymes for making NT, receptors?

49
Q

What does CREB do to produce effects of drugs?

A
  • within the NAc:

- leads to increased production of dynorphin: opioid substance, binds to kappa-receptors

50
Q

Does the NAc send GABA-ergic and dynorphin-ergic input back to the ventral tegmental area?

A

-yes

51
Q

What does the increase in hynorphin release for the NAc do?

A
  • turns the input from the VTA off, reducing the effect of the drugs
  • this is part of the process of desensitization that occurs with drug addiction
52
Q

What is associated with the Activation of CREB within the locus ceruleus and the periaquaductal grey?

A
  • the physical dependence on the drugs

- the mechanism for this is unclear

53
Q

are changes in CREB temporary?

A
  • yes

- they return to normal within a week of drug abstinence

54
Q

What is delta-FosB?

A
  • a long term response to drug addiction

- also a regulator of transcription

55
Q

Describe the Major features of drug addiction and relate them to the neural changes induced by the drugs?

A
  • The stronger stimulation can produce LTP in VTA neurons: more synapses, more response to released DA, increase in CREB production/activity, Increase dynorphin release in VTA
  • Delta FosB: longer lasting effects than CREB, mostly associated with anatomic changes in synapses (more synapses, more dendritic spines)
56
Q

What is synaptic plasticity?

A
  • changes in the anatomy and physiology of synapses associated with learning
  • some changes are permanent, others more transient
57
Q

What is long-term potentiation?

A
  • increase in response to same stimulus
  • changes in both the pre and post synaptic neurons
  • include: increased NT release, increased post synaptic responses due to changes in the receptors to which the NT binds

BPS (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions