Brainscape's Knowledge GenomeTM

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


See full index

PSYC 2800 > Chapter 3 - Neurotransmission > Flashcards

Chapter 3 - Neurotransmission Flashcards

1
Q

Neurotransmission

A

Transmission of info between neurons; involves a release of chemical(s) from pre synaptic neuron into a synapse following an action potential; action of a chemical on adjacent post synaptic neuron

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

Electric potential

A

Local difference between the electrical charge inside and outside of a neuron (across cell membrane)

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

Depolarization

A

Reduction in the electric potential; brings neuron closer to firing threshold

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

Hyperpolarization

A

Increase in the electric potential; moves neuron away from firing threshold

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

When is a neuron polarized?

A

At rest (-70mV)

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

Resting potential

A

The electrical potential when neuron is not firing (-70mV); remains relatively stable

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

Action potential

A

Rapid depolarization of an axon; becomes positive inside

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

What happens during an action potential?

A

Begins at axon hillock; happens when another neuron depolarizes cell; firing threshold (-55mV) must be reached; Na+ channels open; Na+ rapidly enters cell; inside of cell reverses polarity locally (+30mV); Na+ channels close and K+ exits

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

Refractory period

A

Time during which resting potential is being restored

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

“All or none” law

A

Neuron never partially fires; if firing threshold is not reached it will not fire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Firing rate

A

Depends on the amount of stimulation by other neurons; is limited by the refractory period (cell needs to reset)

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

Propagation

A

Conduction of an action potential down an axon; begins at axon hillock; Na+ channels open in succession down axon; speed along axon depends on diameter of neuron

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

Saltatory conduction

A

Occurs in axons that are myelinated; results in “skipping” action down neuron (increases speed of propagation)

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

Neurotransmitters

A

Signalling molecules for neuronal communication; synthesized by neurons; released from nerve terminals; have effects on other neurons or glands/muscles in periphery; main site of action for most psychoactive drugs

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

Synthesis (neurotransmitter lifecycle)

A

Usually made from precursor molecules (ex. Amino acids); either in nerve terminals or in somas

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

Storage (neurotransmitter lifecycle)

A

If not used immediately, contained within vesicles that protect from degradation enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Release (neurotransmitter lifecycle)

A

In response to action potentials; voltage dependent Ca++ channels to open; vesicles bind to presynaptic membrane and released into synapse

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

Binding to receptors (neurotransmitter lifecycle)

A

Ligands bind to protein receptors on post-synaptic neurons

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

Termination of action (neurotransmitter lifecycle)

A

Several methods to stop action of neurotransmitter (ex. Catabolism by enzymes, re-uptake)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Receptors

A

Specialized proteins embedded in neuronal membranes to which neurotransmitters bind and activate; binding depends on location and type of receptor; can have immediate (change local potentials) or long term effects (alter gene expression/protein synthesis); a given NT may have several types of receptors (different effects)

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

Post synaptic receptors

A

Located on post-synaptic neuron

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

Pre synaptic neuron

A

Located on pre synaptic neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Auto-receptors

A

Stimulated by NT released from pre synaptic neuron; inhibit pre synaptic neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Heteroreceptors

A

Stimulated by other NTs (not released from pre synaptic neuron); not same class of NT released by pre synaptic neuron; may increase or decrease pre synaptic neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Ionotropic (classes of receptors)

A

Receptor is coupled to an ion channel embedded in the neuron membrane; when NT binds to the receptor, ion channels open; ions (Na+ Cl-) enter the cell; local membrane potential is either depolarized or hyperpolarized; effect ends when NT is no longer bound to receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Metabotropic (types of receptors)

A

Receptor is coupled to a G protein (not an ion channel) embedded in the neuron membrane; when NT binds to the receptor, G protein is activated in the cell; initiates intracellular signalling

27
Q

Amino acids (types of NT)

A

Glutamate, gamma aminobutyric acid (GABA)

28
Q

Monoamines (type of NT)

A

Catecholamines (dopamine, norepinephrine, epinephrine); indoleamines (serotonin, melatonin)

29
Q

Neuropeptides (type of NT)

A

Endorphines (beta-endorphin, met-enkephalin)

30
Q

Gases (type of NT)

A

Nitric oxide

31
Q

Most NTs are synthesized from ____

A

amino acids

32
Q

Glutamate

A

Synthesized from glutamine (AA in diet) in neurons; converting enzyme (glutaminase); transported into vesicles within producing neuron; released in high quantities in cortex

33
Q

Glutamate termination

A

Transported back into releasing cells and restored OR broken down into glutamine (glutamine synthetase)

34
Q

Glutamate receptors

A

3 ionotropic (post-synaptic) receptors: NMDA, APMA, kainate receptors

35
Q

Astrocytes

A

Play an important role in regulating glutamate neurotransmission; have glutamate receptors and transporters; may break down glutamate into glutamine

36
Q

GABA (gamma amino butyric acid)

A

Derived from glutamate by an enzyme (glutamic acid decarboxylase); most abundant inhibitor; receptors: GABAA, GABAB

37
Q

GABAA Receptor

A

ionotropic; coupled to Cl- ion channel; hyperpolarizes post synaptic neurons; widespread distribution in brain; site of action of depressants

38
Q

GABAB Receptor

A

Matabotropic; coupled to G protein; inhibitory effects

39
Q

Astrocytes (GABA)

A

Termination of GABA neurotransmission; GABA taken up by transporters on astrocytes; metabolize GABA into glutamate/glutamine

40
Q

Monoamines

A

Single amine group (NH2) in chem structure; target of many psychoactive drugs ex. Dopamine (reward/addiction, movement), norepinephrine (mood, arousal, attention), serotonin (mood)
two classes: catecholamines, indoleamines

41
Q

Dopamine synthesis

A

First NT in catecholamine synthesis pathway; tyrosine first converted to L-DOPA via the enzyme tyrosine hydroxylase

42
Q

Dopamine receptor families

A

D1 (D1 & D5): excitatory on post synaptic neurons
D2 (D2, D3, D4): inhibitory on post synaptic neurons
All metabotropic

43
Q

Dopamine termination of action

A
  1. Catabolism by enzymes monoamine oxidase (degrade all monoamines) and catecol-O-methyl transferase (only break down catecholamines) 2. Reuptake
44
Q

Mesolimbic dopamine pathway

A

From VTA (midbrain) to limbic areas, notably nucleus accumbens, amygdala, hippocampus

45
Q

Mesocortical dopamine pathway

A

From VTA to neocortex incl. pre frontal cortex; over-activation associated with schizophrenia; target of anti-psychotic drugs

46
Q

Nigrostriatal dopamine pathway

A

From substantia nigra (midbrain) to basal ganglia; degradation = Parkinson’s

47
Q

Tubero-infundibular dopamine pathway

A

From PVN of hypothalamus to posterior pituitary; controls release of prolactin

48
Q

Norepinephrine synthesis

A

Next NT in catecholamine synthesis in pathway after DA; DA is converted by an enzyme into NE

49
Q

Norepinephrine receptors

A

All metabotropic
Two families: alpha and beta
a1 (excitatory), a2 (inhibitory, pre synaptic auto receptors), b1/2/3 (excitatory)

50
Q

NE termination

A

Catabolic enzymes or reuptake

51
Q

Norepinephrine pathway

A

locus coeruleus (hindbrain) projects to cerebral cortex/amygdala/hippocampus

52
Q

Serotonin synthesis

A

In serotonergic neurons; synthesized from essential AA tryptophan; stored in vesicles; also produced in gut cells

53
Q

Serotonin receptors

A

Seven major types: 5-HT1 to 7
Subtype 5-HT1A
Most are excitatory

54
Q

Serotonin termination

A
  1. monoamine oxidase
  2. reuptake: serotonin transporters on pre synaptic neurons (SSRIs block these receptors)
55
Q

Serotonin pathways

A

Raphe nuclei in midbrain projects to several regions of brain (forebrain); also to spinal cord to regulate pain; regulates pain and food intake

56
Q

Acetylcholine (ACH) synthesis

A

In cholinergic neurons; synthesized from choline (diet) and acetyl coenzyme A

57
Q

nicotinic (ACH cholinergic receptors)

A

named for nicotine; ionotropic (excitatory); coupled to pos ion channels Na+ K+ Ca++

58
Q

muscarinic (ACH cholinergic receptors)

A

named for muscarine; facilitates ACH neurotransmission; metabotropic (mostly inhibitory)

59
Q

Acetylcholinesterase (ACH termination)

A

breaks down ACH into choline and acetic acid

60
Q

Nucleus basalis of Meynert (ACH pathways

A

major source of ACH in basal forebrain; supplies ACH to cortex and limbic areas; very important for memory
note: early treatment for Alzheimer’s attempts to boost ACH levels

61
Q

Neuropeptides

A

sequence of amino acids; often produced in somas; sometimes co released with other NTs

62
Q

Neurotrophins

A

growth factors

63
Q

Hormones

A

signaling molecules that communicate over larger distances carried by blood to distant targets (ex. prolactin, oxytocin, melatonin)

PSYC 2800 (12 decks)

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