4 - Catecholamines Flashcards

1
Q
  1. There are at least __ receptors for 5-HT; most are __
  2. 5-HT1A receptors are concentrated in the __, __ area, __, and __ Raphe nucleus.
  3. They reduce cAMP synthesis by inhibiting __ __ (just like D2 and α2 receptors).
  4. They increase opening of __ __ and membrane __
A

14 | Metabotropic

Hippocampus | Septal | Amygdala | Dorsal

cAMP Synthesis | Adenylyl Cyclase

K+ channels | Hyperpolarization

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2
Q
  1. Reserpine (VMAT blocker) depletes __-__ (it is broken down when not protected in vesicles)
  2. Terminal autoreceptors directly inhibit __-__ release
  3. Somatodendritic autoreceptors indirectly inhibit its release by slowing the rate of __ __
A
  1. 5-HT
  2. 5-HT
  3. Neuron Firing
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3
Q
  1. 5-HT3 receptors are located on Peripheral Terminals of the __ __
  2. Chemotherapy drugs and radiation stimulate release of __-__ in the __, which stimulates vagal 5-HT3 receptors and __ __
  3. __-___ __ such as Ondansetron (Zofran), Granisetron (Kytril), and Palonosetron (Aloxi) are used to treat the nausea
A
  1. Vagus Nerve
  2. 5-HT | Gut | Induces Vomiting
  3. 5-HT3 Antagonists
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4
Q

5-HT release is stimulated by a drug family based on amphetamine

  1. Para-Chloroamphetamine is mainly used __
  2. Fenfluramine was prescribed for __ __ in obese patients
  3. Studies in squirrel monkeys showed that repeated high doses resulted in depletion of __ __ in the brain
  4. Used in low doses to treat chronic _ _ _ _
A
  1. Experimentally
  2. Appetite Suppression
  3. Serotonergic Axons
  4. PTSD
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5
Q

Adjectival Forms of Catecholamines are (3)

A
  • Dopaminergic
  • Noradrenergic
  • Adrenergic
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6
Q

The __ __ secretes __ and __ into the bloodstream where they act as hormones

Neurotransmitter function of __ is relatively minor

A

Adrenal Medulla | Epinephrine | Norepinephrine

Epinephrine

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7
Q

Epinephrine and Norepinephrine are also known as __ and __

A

Adrenaline and Noradrenaline

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8
Q
  1. Adrenergic Receptors (adrenoceptors) are __. There are two subtypes, __ and __
  2. α2-receptors reduce synthesis of __ (like D2 receptors)
  3. α1-receptors operate via __ __-__ __ (frees up Ca2+ ions in the cell)
  4. β1- and β2-adrenoceptors stimulate Adenylyl Cyclase and enhance __ __ __ (like D1 receptors)
A
  1. Metabotropic | α | β
  2. cAMP (Cyclic Adenosine Monophosphate)
  3. α1-receptors | Phosphoinositide Second-Messenger System
  4. Synthesis of cAMP
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9
Q

Brain areas involved in __ receive substantial Serotonergic __ and express several 5-HT receptor subtypes

A

Aggression | Innervation (stimulate a nerve; supply energy to)

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10
Q

Agonists that activate both α- and β-receptors are used to treat bronchial asthma, but Asthma is more commonly treated with a selective β2-agonist, such as Albuterol (Ventolin), in an inhaler, because Beta-receptors in the airways are __ subtype; the heart has mainly __ subtype. Therefore Albuterol alleviates bronchial congestion without producing __ __ __

A

β2 | β1 | Adverse Cardiovascular Effects

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11
Q

Adrenergic Agonists or Antagonists are often used in treatment of non-psychiatric conditions because of the widespread distribution of adrenergic receptors in __ __

A

Peripheral Organs

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12
Q

Pain felt in response to a stimulus that is not usually painful

A

Allodynia

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13
Q

Some drugs cause release independently of cell firing, like __ and __, which trigger both __ and __ release

A

Amphetamine and Methamphetamine | Catecholamine and Serotonin

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14
Q

β1 is the main subtype in the heart; β1-selective antagonists, such as Metoprolol (Lopressor), have fewer side effects.

• β-antagonists (beta blockers) are also used to treat __ __ __. They reduce the physical symptoms, such as __, __, and __ (racing heart)

A

Generalized Anxiety Disorder | Palpitations | Flushing | Tachycardia

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15
Q

The α1-antagonist Prazosin (Minipress) blocks α1-receptors that cause blood vessel constriction

The general β-antagonist Propranolol (Inderal) blocks β-receptors in the heart, reducing its contractile force

This makes them both good __ for treating __

A

Antagonists | Hypertension

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16
Q
  1. __are the most common treatment for several anxiety disorders
  2. The main receptor involved is 5-HT__; the partial 5-HT__ agonist Buspirone (BuSpar) is sometimes prescribed
  3. Presence or absence of 5-HT__ receptors in Forebrain areas during early postnatal development may alter neural circuitry and expression of __ in adult mice
  4. Suggests that deficient 5-HT__ receptor activity during a critical developmental period may give rise to later onset of anxiety disorders in humans
A
  1. SSRIs
  2. 1A | 1A
  3. 1A | Postnatal Development | Anxiety
  4. 1A | Anxiety Disorders
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17
Q

An agonist that stimulates both D1 and D2 receptors. Causes behavioural activation similar to that seen with stimulants like __ and __

A

Apomorphine | Cocaine | Amphetamine

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18
Q

Locus Coeruleus neurons fire more rapidly during __ than during __

Noradrenergic pathways from the __ to the Medial __ and Medial __ areas are involved in wakefulness

Experiment: α1-receptor agonist Phenylephrine and/or general β-receptor agonist Isoproterenol were injected into the Medial Septal area of rats. What happened?

A

Waking | Sleep

Locus Coeruleus | Septal | Preoptic

Spent more time awake

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19
Q

Atomoxetine

A

ADHD Treatment

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20
Q

Catecholamine release is inhibited by __ on neuron cell bodies, terminals, and dendrites

A

Autoreceptors

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21
Q

Drugs that stimulate autoreceptors inhibit catecholamine release, but conversely, __ __ enhance rate of release

A

Autoreceptor Antagonists

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22
Q

The Aversion-Mediating pathway includes input to the VTA from the __ __ (LHb) and Dopaminergic Output from the VTA to the __ __ __ (mPFC)

A

Lateral Habenula | Medial Prefrontal Cortex

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23
Q
  1. If a D2 receptor antagonist, such as Haloperidol, is given to rats on a long-term basis, the rats develop __ __
  2. If the treatment is stopped and an __ (Apomorphine) are given, these rats respond more strongly than control subjects
  3. This behavioral supersensitivity may be due to increased density of D2 receptors on postsynaptic cells in the __. A Lack of normal neurotransmitter input causes the neurons to increase their sensitivity via __ __
A

Behavioral Supersensitivity

Agonists

Striatum | Up Regulation

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24
Q

The memory-enhancing effects of EPI may be mediated by its ability to increase __ __ __

A

Blood Glucose Levels

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25
Q

Breakdown Products

A

Metabolites

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26
Q

Breakdown of Catecholamines by Catechol-O-MethylTransferase (COMT) and Monoamine Oxidase (MAO) into Metabolites

  • DA metabolite (breakdown product) in humans is __ __ Acid.
  • NE metabolites: 3-methoxy-4-hydroxy-phenylglycol (MHPG) in the brain and __ __ Acid in the PNS
  • The metabolites enter the CSF and the bloodstream and are eliminated with __
A

HomoVanillic Acid

VanillyMandelic Acid

Urine

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27
Q
  1. Reserpine administration depletes catecholamines and makes bunnies __
  2. Adminitering DOPA to bunnies thereafter makes them __
A
  1. Lethargic
  2. Energized
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28
Q

Drugs that stimulate autoreceptors, inhibit __ release

A

Catecholamine Release

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29
Q

Cathecholamine Reuptake Transporter-Blocking Drugs:

  • __ __ inhibit re-uptake of both NE and __ (__-__)
  • NE transporter blockers
    • __ an antidepressant
    • __ for ADHD
  • Cocaine inhibits reuptake of all the mono-amine transmitters: __, __, and __-__
A

Tricyclic Antidepressants | NE | Serotonin (5-HT)

Reboxetine (Edronax) | Atomoxetine (Strattera)

DA | NE | 5-HT

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30
Q

Hormones made by your Adrenal Glands, located on top of your kidneys, and sent into your blood when you’re physically/emotionally stressed. Members of this groups all share two chemical similarities: they contain a core structure of catechol and a nitrogen-containing group called an amine.

A

Catecholamines

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31
Q

What are the Catecholamines? (3)

A

Dopamine (DA)

Norepinephrine / Noradrenaline (NE)

Epinephrine / Adrenaline (EPI)

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32
Q

The second enzyme, AADC, is the same for synthesis of __ and __

A

Catecholamines | 5-HT

(Aromatic Amino Acid deCarboxylase)

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33
Q

High Levels of __ tend to inhibit TH (negative feedback)

A

Catecholamine

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34
Q

When neurons are firing at a high rate, such as during stress, TH is stimulated and __ __ accelerates

A

Catecholamine Synthesis

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35
Q

Catecolamines primarily broken down by enzymes __ and COMT (__-__-__)

__ metabolized by MOA-A in humans and rodents

__ metabolized in humans by MOA-B but by MOA-A in rodents

A

Catechol-O-MethylTransferase

NE

DA

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36
Q

__ and Risperidone (Risperdal) block 5-HT2A receptors and __ __ receptors

A

Clozapine | D2 Dopamine

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37
Q

Activation of α1-receptors in the PFC has a deleterious effect on cognitive functions

  • Increased NE associated with stress increases α1-receptor activation, which can lead to __ __
  • NE has a lower affinity for α1-receptors than for the α2-receptor subtype found in high levels in the PFC. Under normal conditions: NE __ PFC function and cognitive tasks by activating α2-adrenoceptors there…
  • Cognitive functions are optimized at intermediate levels of PFC noradrenergic activity. This relates to the __ __ Curve/Law
A

Cognitive Impairment | Facilitates | Optimized | Yerkes-Dodson

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38
Q
  1. Locus Coeruleus also projects to __ __ (PFC), which has roles in cognitive functions like __ and __ __
  2. Activation of α2-receptors in the PFC using selective agonists, such as Clonidine and Guanfacine, enhances __ __. It helps monkeys to not be fooled by __
A
  1. Prefrontal Cortex | Attention | Working Memory
  2. Working Memory | Distractors
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39
Q

Ctecholamine Synthesis Steps (4)

A

Thyrosine

DOPA

Dopamine

Norepinephrine

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40
Q

D2 receptors also regulate membrane __ __

In some cells, D2 receptor stimulation activates a __ __ that enhances K+ channel opening

This causes __ of the cell membrane, decreasing the __ and __ __ of the cell

A

K+ channels | G protein | Hyperpolarization | Excitability | Firing Rate

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41
Q

DA and NE systems have several receptor subtypes

The DA autoreceptor is __ subtype

The NE autoreceptor is __ subtype

Mutant mice with no D2 autoreceptors (but normal postsynaptic D2 receptors in non-DA neurons) were more active than controls and more __ to cocaine

A

D2 subtype

α2 subtype

Autoreceptors | Sensitive

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42
Q

DA receptor knockout mice:

  1. D1 receptor knockout mice exhibit behavioral abnormalities and deficits in __ __
  2. D2 knockout mice show __ __ __
  3. Mice with D1 and D2 double knockouts __
A
  1. Cognitive Tasks
  2. Impaired Movement | Coordination | Posture Control
  3. Die in the second or third week of life
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43
Q
  1. DA uses five receptor subtypes __ to __
  2. All are __. They interact with G proteins and function via __ __
  3. __ and __are similar (D1-like receptors)
  4. __ __ and __ are a separate family (D2-like receptors)
A
  1. D1 to D5
  2. Metabotropic | Second Messengers
  3. D1 | D5
  4. D2 | D3 | D4
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44
Q

Dopaminergic System originates in several cell groups, mostly in the brainstem. Classification system for DA and NE neurons:

  1. Cell groups A1 to A7 are __
  2. Cell groups A8 to A16 are __
A
  1. Noradrenergic
  2. Dopaminergic
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45
Q

Ascending Dopaminergic (DA) system is divided into three pathways

  1. The __ __ axons from the A9 cell group in the __ __ extend to the __ or __-__
  2. The A10 cell group is in the __ __ __. It gives rise to two pathways. Those are:
    • __ __ pathway from the VTA to various structures of the Limbic System
    • __ __ pathway from the VTA to the Prefrontal Cerebral Cortex
A
  1. Nigrostriatal Tract | Substantia Nigra | Striatum (Caudate-Putamen)
  2. Ventral Tegmental Area | Mesolimbic Dopamine | Mesocortical Dopamine
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46
Q

Neurons that synthesize NE also have __ __-__ (3rd enzyme in catecholamine synthesis)

A

Dopamine β-Hydroxylase

47
Q

Evidence from animal studies indicates that NE, EPI, and glucocorticoid hormones modulate the __ of __ __

A

Consolidation | Emotional Memories

48
Q

Many DA and NE axons form __ __ synapses. Fibers exhibit repeated __ (swellings) along their length, filled with __ __

A

En Passant (in passing) | Varicosities | Synaptic Vesicles

49
Q

Most 5-HT is located in the __

Some is found in neurons of the __ Nervous System, a system of ganglia in the muscle walls of the intestines.

More is synthesized by __ cells using the enzyme TPH1, the non-neuronal form of TPH

A

Gut

Enteric Nervous System

Enterochromaffin

50
Q

Epinephrine has undesirable side effects, which diminishes its usefulness as a potential __ __, but glucose (or a drug that boosts __ __ __) might be effective

A

Cognitive Enhancer | Glucose | Blood Glucose Levels

51
Q
  • Phasic (“burst mode”) firing of these Serotonergic Neurons must be triggered by __ __ __
  • Most research on neurotransmitter regulation of Serotonergic Neuron firing has focused on Glutamate, Acetylcholine, and GABA, but other neurotransmitters help regulate, including __, __, and __
A
  • Excitatory Synaptic Inputs
  • DA | NE | Orexin
52
Q

Catecholamines are normally released by __ when a nerve impulse reaches the terminal

A

Exocytosis

53
Q

__ __ are serious side-effects of antipsychotic and other drugs

A

Extrapyramidal Effects/Symptoms

54
Q

Blood-borne NE and EPI work with NE released as a transmitter (from sympathetic nerves) to mediate the physiological changes that make up the __ __ __ response, which is comprised of 3 primary effects. What are they?

A

Fight-or-Flight

  • elevated blood pressure and heart rate
  • decreased digestive activity
  • dilation of blood vessels to skeletal muscles, heart and brain
55
Q
  • 1 - (2,5-DimethOxy-4-IodoPhenyl)-2-AminoPropane (DOI) is a 5-HT-__ __
  • DOI and related drugs are __ in humans
  • The hallucinogenic effects of Lysergic Acid Diethylamide (LSD) are believed to stem from its ability to stimulate __-__ __
A

5-HT2A Agonist | Hallucinogenic | 5-HT2A receptors

56
Q

DA receptor Antagonists suppress exploratory and locomotor behaviour. At higher doses, such drugs can result in __, which is lack of spontaneous movement. Usually associated with D2 receptor blockers such as __ but also __ __ such as SCH 23390

A

Catalepsy | HaloPeridol | D1 Blockers

57
Q

5-HT1A receptor activation improves performance in spatial learning and memory tasks, probably due to their high density in the __

But activation of __ 5-HT1A receptors was shown to impair memory encoding in a contextual fear-conditioning task

Cognition is improved when animals are treated with a 5-HT6 receptor antagonist

The 5-HT6 Receptor Antagonist idalopirdine has been tested clinically in patients with __ __

A

Hippocampus

Hippocampal

Alzheimer’s Disease

58
Q
  1. 5-HT1B or 5-HT2C Receptor Agonists, and 5-HT6 Antagonists produce __, or reduced food intake
  2. The 5-HT–releasing drug Fenfluramine was used to treat obesity, but caused heart valve abnormalities and __ __
  3. __ __ __ were caused by activation of 5-HT2B receptors in the heart valve tissue
  4. The __ (appetite-reducing) effect could be traced in part, to activation of Hypothalamic 5-HT2C receptors
  5. Lorcaserin (Belviq), a selective 5-HT2C agonist, was developed to treat
A
  1. Hypophagia
  2. Pulmonary Hypertension
  3. Cardiac Side Effects
  4. Anorectic
  5. Obesity
59
Q

__ is an increased sensitivity to stimuli that are usually painful

A

Hyperalgesia

60
Q
  1. Some drugs block pain signals transmitted by the trigeminal nerve, which is responsible for __ __ and __ __ like __ and __
  2. Transdermal Sumatriptan (Zecuity) uses ____ to move drug molecules. It uses a __ __ on the skin.
A
  1. Face Sensation | Motor Functions | Biting | Chewing (most complex of cranial nerves)
  2. Iontophoresis | Voltage Gradient
61
Q

D1 receptor knockout mice exhibit __ __

Mice lacking D1 receptors (D1–/–) are insensitive to the locomotor-stimulating effects of __

A

Behavioral Abnormalities | Cocaine

62
Q
  1. LateroDorsal Tegmentum to Nucleus Accumbens is the __ __ __
  2. Lateral Habenula to Medial Prefrontal Cortex is the __ __ __
A
  1. Reward-Mediating Pathway
  2. Aversion-Mediating Pathway
63
Q

One-Trial Passive Avoidance Learning Paradigm is commonly used to evaluate __ __. Longer avoidance = __ __

A

Memory Consolidation | Better Learning

64
Q

Stress associated with One-Trial Passive Avoidance Learning produces increased EPI and glucocorticoid secretion from the __ __

Central noradrenergic neurons also increase NE release in the brain

All of these processes are believed to play some role in __ __ __ __

A

Adrenal Glands

Passive Avoidance Memory Consolidation

65
Q

MethyleneDioxyMethAmphetamine is a recreational drug knwon as

A

MDMA | Ecstasy

66
Q

MHPG

A

3-Methoxy 4-Hydroxy PhenylGlycol

67
Q

Mesencephalon

A9 Cell group associated with the…

Caudate-Putamen or…

A

Mid-Brain

Substantia Negra

Dorsal Striatum

68
Q

Abnormal dilation of blood vessels in the brain contributes to migraine headaches

__ are 5-HT1B/1D agonists [like sumatriptan (Imitrex) and zolmitriptan (Zomig) that cause __ __ to ease pain

A

Triptans | Vessel Constriction

69
Q

Drugs that inhibit breakdown enzymes:

  1. __ inhibitors like Phenelzine (Nardil) and Tranylcypromine (Parnate) are used to treat depression
  2. __ inhibitors like Entacapone (Comtan) and Tolcapone (Tasmar) enhance the effectiveness of __-__ in treating Parkinson’s disease by preventing breakdown of __
A
  1. MAO
  2. COMT inhibitors (inhibits enzyme Catechol-O-MethylTransferase) | L-DOPA | DOPA
70
Q

Catecholamines belong to a wider group of transmitters called either __ or Biogenic Amines.

A

Monoamines or __ __

71
Q

__ __ damage can lead to a form of chronic pain called __ pain

A

Nerve tissue | Neuropathic

72
Q

Neuron firing patterns (2 modes) also influences catecholamine release

  • __ __ mode: action potentials generated at irregular intervals resulting in __ release of DA.
  • __ mode: trains of 2 to 20 spikes at a higher frequency result in __ release of DA and causing extracellular level of DA to be high because its release occurrs faster than it can be cleared and/or metabolized.
A
  1. Single-Spiking | Tonic 4-5 Hz
  2. Burst (2-10) | Phasic ~20 Hz
73
Q

Noradrenergic System has Central and PNS components

Central

  • Cell bodies in the Brainstem (__ __ and __)
  • Their ascending fibers go to Forebrain Structures.

Peripheral: part of the Sympathetic Nervous System

  • NE neuron fibers extend to target __ throughout the body
A
  • Locus Coeruleus and Medulla
  • Forebrain Structures
  • Organs
74
Q

The central Noradrenergic System is involved in many behavioral functions. Of special interest are 3 things:

A
  1. Arousal
  2. Cognition
  3. Consolidation of memories of emotional experiences
75
Q
  1. Catecholamine Release leads to __ __
  2. In lab animals, increased __ __ occurs. At higher doses, this is replaced by __ behaviours (sniffing, head and limb movements, licking and biting)
  3. This continuum of behaviour stems from increasing stimulation of DA receptors in the __ __ and __
A
  1. Behavioral Activation
  2. Locomotor Activity | Stereotyped
  3. Nucleus Accumbens and Striatum
76
Q

Reduced by treatment with agonists at the 5-HT1A, 5-HT1B, and 5-HT2C receptor subtypes. Exacerbated by 5-HT2A and 5-HT4 agonists

A

Pain

77
Q
  1. There are large numbers of __-__ Receptors in the Cortex. They activate the __ __-__ __ (just like α1-receptors)
  2. This system increases Ca2+ levels in postsynaptic cells and also activates __ __ __
A
  1. 5-HT2A | PhosphoInositide Second-Messenger System
  2. Protein Kinase C (PKC)
78
Q

A family of minority acidic phospholipids in cell membranes. Their principal role is instructional: they interact with proteins

A

PhosphoInositides

79
Q

Catecholamine Synthesis can be increased by administering __ such as __ or __ __, which has been used to treat __ __

A

Precursors | Tyrosine | L-DOPA | Parkinson’s Disease

80
Q
  1. Almost all Serotonergic Neurons in CNS found along the __ __ __ associated with the __ __
  2. The Dorsal and Median __ __ give rise to most of the Serotonergic Fibers in the __
A
  1. midline of Brainstem | Raphe Nuclei
  2. Raphe Nuclei Forebrain

____

(image - Tonic Firing Patterns)

81
Q

TH (Tyrosine Hydroxylase) is the __ __ Enzyme in the pathway. It determines the overall rate of DA or NE synthesis.

A

Rate-Limiting

82
Q

Reboxetine

A

Antidepressant

83
Q
  1. 5-HT plays a role in processing of pain signals at the level of the spinal cord
  2. The complex role involves several __ __ that together produce either __ or __ modulation
A
  1. 5-HT
  2. Receptor Subtypes | Inhibitory | Excitatory
84
Q

__ __ __ and __ help us understand which behaviours are under the control of a particular receptor subtype

SKF 38393 is an Agonist for D1 receptors; Quinpirole activates __ and __ receptors (stimulating hyperactivity)

A

Receptor Selective Agonists | Antagonists

D2 | D3 Receptors | Hyperactivity

85
Q

VMAT can be blocked by the drug __

A

Reserpine

86
Q

__ for hypertension blocks storage of __, __, and _-__ in vesicles

A

Reserpine | DA | NE | 5-HT

87
Q
  • Most common behavioural effect of eliminating brain 5-HT is a large increase in __ __, usually measured by the __-__ __
  • Injection of 5-HTP with Carbidopa, an AADC inhibitor that doesn’t cross the blood–brain barrier, reverses the effect because it __ __ __ of 5-HTP to 5-HT
  • 5-HT knockout mice are __ __ __ and attack more times
  • If given 5-HTP and Carbidopa they are __ __ __ and __ __ __
A
  • Aggressive Behaviour | Resident-Intruder Test
  • Blocks Peripheral Conversion
  • Quicker to Attack | Attack More Times
  • Slower to Attack | Attack Fewer Times
88
Q
  1. During Reuptake of Catecholamines __ and __ move from the synaptic cleft into the nerve terminal via specific __ __ __
  2. The molecules are then __ into vesicles or __ __
  3. __ __ Uptake plays a vital role in the normal regulation of catecholamine activity
  4. Mice with no __ __ do not respond to psychostimulants like cocaine and amphetamine
  5. Mutant mice with no __ __ have increased sensitivity to psychostimulants
A
  1. DA | NE | Membrane Transporter Proteins
  2. Repackaged or Broken Down
  3. Transporter-Mediated
  4. DA transporters
  5. NE transporters
89
Q

The Reward-Mediating pathway includes input to the VTA from the __ __ (LDT) and Dopaminergic Output from the VTA to the __ __ (NAc)

A

LateroDorsal Tegmentum | Nucleus Accumbens

90
Q

Some personality disorders are associated with violent behaviours; drugs that can quell such behaviors are called __

SSRIs have been tested because of their ability to enhance __ __

• E.g., fluoxetine (Prozac)

A

Serenics | Serotonergic Transmission

91
Q
  • Breakdown of 5-HT is catalyzed by MAO-A to yield 5-_ _ _ _ (HIAA)
  • Levels of 5-HIAA in the brain or CSF sre used as a measure of the activity of __ __
A

MAO-A 5-HydroxyIndoleAcetic Acid (5-HIAA) | Serotonergic Neurons

92
Q

Proposes that low CNS Serotonergic activity is associated with hyperaggressiveness

A

Serotonin Deficiency Hypothesis of Aggression

93
Q
  • After release 5-HT is rapidly removed from synaptic cleft via reuptake by the __-__ __, or __
  • These transporters are blocked by __ __ __ __ such as Fluoxetine (Prozac)
  • Cocaine and MDMA also block SERT, but are not selective. They also affect __ transporters
A

5-HT transporter | SERT

Selective Serotonin Reuptake Inhibitors (SSRIs)

Cocaine | MDMA | DA

94
Q

Enterochromaffin Cell 5-HT is released onto sensory nerve endings in the gut wall, after which it is cleared from the extracellular space by __

When food is ingested, 5-HT promotes gut __ and __ __

A

SERT

Peristalsis | Secretory Activity

95
Q
  1. __ enhance the opening voltage-gated K+ channels, which shortens the duration of __ __ and reduces Ca2+ influx, and thus __
  2. __ __ inhibit neurotransmitter release indirectly by reducing the rate of firing of the cell
A
  1. Autoreceptors | Action Potentials | Exocytosis
  2. Somatodendritic Autoreceptors
96
Q

NE can reach an organ such as the heart in two ways:

  1. It can be released from __ __ __ at synapse-like contacts with Cardiac cells.
  2. It can be released from the __ __ and travel in the bloodstream to the heart (but cannot cross the __-__ __)
A
  1. Sympathetic Noradrenergic Neurons
  2. Adrenal Glands | Blood Brain Barrier
97
Q

Neurons can regulate __ of neurotransmitters and control the amount available for release.

Drugs can also be used to promote or block it (e.g., administering __ __)

A

Synthesis | Transmitter Precursors

98
Q

TH can be phosphorylated by all of the second-messenger-associated Kinases from Chapter 3, including __, __, __, and __/__ __ __. It can also be phosphorylated by kinases of the MAP (Mitogen-Activated Proten) Kinase system including ERK (extracellular signal-related Kinase)

A

A, G, C, and Calcium/Calmodulin Kinase II

99
Q

Serotonin is synthesized from the amino acid _____ in two steps

  1. Tryptophan Hydroxylase converts Tryptophan to __-__
  2. __ __ __ __ converts 5-HTP to 5-HT (serotonin)
A

Tryptophan

  1. 5-HydroxyTryptoPhan (5-HTP)
  2. Aromatic Amino Acid Decarboxylase (AADC)
100
Q

A low-protein, high-carbohydrate meal will increase ratio of __ to competing Large Neutral Amino Acids (LNAA), allowing more __ to cross the __–__ __ and more __-__ to be made

A

Tryptophan | Tryptophan | Blood–Brain Barrier | 5-HT

101
Q

Ratio of Tryptophan to other amino acid competitors for transport across blood–brain barrier determines whether __ __ is stimulated or not

A

Serotonin Synthesis

102
Q

Tryptophan hydroxylase is found only in __ __

A

Serotonergic Neurons

103
Q

Conversion of Tryptophan to 5-HTP is the __ __ __

A

Rate-Limiting Step

104
Q

There are two forms of the Tryptophan Hydroxylase gene

  • TPH2 is expressed by __ __
  • TPH1 is expressed by 5-HT-secreting cells in the __ and __ secreting cells in the __ __
A

Serotonergic Neurons

Gut | Melatonin | Pineal Gland

105
Q

Catecholamine synthesis begins with the amino acid __

A

Tyrosine

106
Q

__ __ and __ __ __ __ are found in neurons that make Dopamine (first 2 enzymes in catecholamine syntesis)

A

Tyrosine Hydroxylase | Aromatic Amino Acid deCarboxylase

107
Q

After synthesis, catecholamines are packaged into

A

Vesicles

108
Q

A specific transporter in the __ __ membrane known as the __ __ __ recognizes monoamines

A

Vesicle Membrane | Vesicular MonoAmine Transporter (VMAT)

109
Q

Serotonin is transported into vesicles by __ (__ __ __)

A

VMAT2 (Vesicular Monoamine Transporter)

110
Q

VMAT 1 is found in the __ __

VMAT 2 is present in the __

Both are blocked by ______

A

Adrenal Medula

Brain

Reserpine

111
Q

A widespread mode of intercellular communication that occurs in the extracellular fluid (ECF) and in the cerebrospinal fluid (CSF) of the brain with signals moving from source to target cells via energy gradients leading to diffusion and convection (flow)

A

Volume transmission

112
Q

Some VTA Dopaminergic Neurons are activated by stressful or aversive stimuli

  • It appears that __ and __ stimuli activate different subsets of VTA neurons

These subsets are also differentiated by both their inputs and their outputs:

  • The __-__ pathway includes input to the VTA from the LateroDorsal Tegmentum (LDT) and dopaminergic output from the VTA to the Nucleus Accumbens (NAc)
  • The __-__ pathway includes input to the VTA from the Lateral Habenula (LHb) and dopaminergic output from the VTA to the Medial Prefrontal Cortex (mPFC)
A
  • Rewarding | Aversive
  • Reward-Mediating (LateroDorsal Tegmentum to Nucleus Accumbens)
  • Aversion-Mediating (Lateral Habenula to Medial Prefrontal Corte)
113
Q
  1. Withdrawal from opioids activates the __ System, one factor leading to withdrawal symptoms
  2. __ __ such as Clonidine are often used to treat the symptoms
  3. Yohimbine blocks the __ and thus increases __ __ __ and NE release. It was found to provoke __ __ and __ __ in opioid-dependent patients
A
  1. Noradrenergic System
  2. α2-Agonists
  3. Autoreceptors | Noradrenergic Cell Firing | Withdrawal Symptoms | Drug Craving
114
Q

__-__-__-__ (AMPT) blocks TH, preventing overall __ __ and causing general depletion of these neurotransmitters

A

α-Methyl-Para-Tyrosine | Catecholamine Synthesis