Lecture 4 Flashcards
1
Q
difference in electrical charge between the inside and the outside of a cell
A
membrane potential
2
Q
membrane potential is measured with the use of _______
A
microelectrodes
3
Q
resting membrane potential is measured as about _____
A
-70 mV charge
4
Q
neuron state of resting membrane potential
A
polarized
5
Q
membrane potential of a polarized neuron
A
not 0
6
Q
in resting neurons, there are more _____ ions outside the cell while there are more ____ ions inside the cell
A
- Na+ ions
- K+ ions
7
Q
specialized pores in the neural membrane
A
ion channels
8
Q
2 types of pressure
A
- electrostatic pressure
- pressure from random motion
9
Q
transporter discovered by Alan Hodgkin and Andrew Huxley in the 1950s
A
sodium-potassium pumps
10
Q
disturbance of the resting membrane potential
A
postsynaptic potentials (PSPs)
11
Q
2 effects when neurotransmitters are released
A
- depolarize of receptive membrane
- hyperpolarize of receptive membrane
12
Q
decreasing the resting membrane potential
A
depolarize of receptive membrane
13
Q
increasing the resting membrane potential
A
hyperpolarize of receptive membrane
14
Q
this depolarization is an upward deflection on the oscilloscope
A
postsynaptic depolarization
15
Q
other term for postsynaptic depolarization
A
excitatory postsynaptic potentials (ESPs)
16
Q
postsynaptic depolarization ___ the likelihood that the neuron will fire
A
increase
17
Q
this hyperpolarization is a downward deflection on the oscilloscope
A
postsynaptic hyperpolarization
18
Q
postsynaptic hyperpolarization is also called
A
inhibitory postsynaptic potentials
19
Q
postsynaptic hyperpolarization ____ the likelihood that the neuron will fire
A
derease
20
Q
ESPs and ISPs are all ____
A
PSPs
21
Q
ESPs and ISPs are ______, meaning the amplitudes of PSPs are proportional to the intensity of the signals that elicit them
(e.g., weak signals elicit small PSPs, and strong signals elicit large ones)
A
graded potential
22
Q
important characteristics of transmission of PSPs
A
- it is rapid
- is is decremental
23
Q
determines whether a neuron fires
A
- net effect of synapsis activity
- balance between excitatory and inhibitory signals
24
Q
a massive but momentary—lasting for 1 millisecond—reversal of the membrane potential from about −70 to about +50 mV.
A
action potential
25
action potential are _____ responses
all-or-none
26
what does "all-or-none" responses mean
they either occur to their full extent or do not occur at all
27
summation of postsynaptic potentials
- spatial summation
- temporal summation
28
summation occurs when EPSPs and IPSPs from different locations on neurons make their way to the axon initial segment and summate there
spatial summation
29
occurs when EPSPs and IPSPs from a single location on a neuron make their way to the axon initial segment and summate there
temporal summation
30
3 possible combinations under spatial summation
- 2 EPSPs summated to produce a greater EPSP
- 2 IPSPs summated to produce a greater IPSP
- 1 EPSP and 1 IPSP cancel each other out
31
conduction of action potentials
- ionic basis
- refractory periods
- axonal conduction
- the hodgkin-huxley model in perspective
32
an action potential is brought on by momentary variations in the permeability of the membrane for diffusible ions from the perspective of ions
ionic basis
33
(refractory period) period during which it is possible to fire the neuron again but only by applying higher-than normal levels of stimulation
relative refractory period
34
[refractory period wherein] there is a brief period of about 1 to 2 milliseconds after the initiation of an AP during which it is impossible to elicit a second AP; followed by the relative refractory period
absolute refractory period
35
responsible for two important characteristics of neural activity
refractory periods
36
2 important characteristics of neural activity:
- responsible for the normal travel of Als along axons in one direction
- responsible for the relationship between neural firing rate and the intensity of the stimulation
37
2 important ways of how AP conduction along an axon differs from PSP conduction
- Al conduction is non-decremental
- APs are conducted more slowly than PSPs
38
an action potential will be generated and will
travel along the axon back to the cell body, given that the electrical stimulation of sufficient intensity is applied to the terminal end of an axon
antidromic conduction
39
axonal conduction in the natural direction from cell body to terminal buttons
orthodromic conduction
40
transmission of action potentials in myelinated actions
saltatory conduction
41
provided a simple, effective introduction to what we now understand about the general ways in which neurons conduct signals
Hodgkin-Huxley model
42
synaptic transmission: from electrical signals to ______ signals
chemical
43
synapses of axon terminal buttons on dendrites
axodendritic synapses
44
small nodules on dendrite surfaces where many axodendritic synapses terminate
dendritic spines
45
synaptic arrangement examples:
- axodendritic synapses
- axosomatic synapses
- dendrodendritic synapses
- axoaxonic synapses
46
most common synaptic arrangements
- axodendritic synapses
- axosomatic synapses
47
synapses at which the site of release is at some distance from the site of reception
nondirected synapses
48
with close proximity between the site of neurotransmitter release and receptors
directed synapses
49
mediate presynaptic facilitation and inhibition
axoaxonic synapses
50
large neurotransmitters are called ______
neuropeptides
51
neuropeptides are ______ composed of between 3 and 36 amino acids
short amino acid chains
52
they are short proteins
neuropeptides
53
concept in neuron which states that many neurons can contain two neurotransmitters
co-existence
54
process of neurotransmitter release
exocytosis
55
proteins with specific binding sites for particular neurotransmitters
receptors
56
any molecule that binds to another
ligand
57
subtypes of receptors
- ionotropic receptors
- metabotropic receptors
58
(receptor subtype) ligand-activated ion channels
ionotropic receptors
59
(receptor subtype) associated with signal proteins and G proteins
metabotropic receptors
60
metabotropic receptors with two unconventional traits
autoreceptors
61
two unconventional traits of autoreceptors
- bind to their neuron's own neurotransmitter molecules
- found on the presynaptic membrane rather than the postsynaptic one
62
2 mechanisms preventing the clogging of synapse
- reuptake by transporters
- enzymatic degradation
63
narrow spaces between adjacent cells bridged by protein channels
gap junctions
64
protein channels
connexins
65
other term for gap junctions
electrical synapses
66
gap junctions connect the ____ of two neighboring cells
cytoplasm
67
neurotransmitters are crucial for _____ in the nervous system as they play essential roles in transmitting signals between neurons
intercellular communication
68
classes of neurotransmitters
- amino acid neurotransmitters
- monoamine neurotransmitters
- acetylcholine
- unconventional neurotransmitters
- neuropeptides
69
molecular building blocks of proteins
amino acids
70
4 primary amino acid neurotransmitters
- glutamate
- aspartate
- glycine
- gamma-aminobutyric acid (GABA)
71
most prevalent excitatory neurotransmitter
glutamate
72
most prevalent inhibitory neurotransmitter but can have excitatory effects in some synapses
GABA
73
synthesized from single amino acids
monoamines
74
monoamines have ____ effects and are found in groups of neurons primarily in the ___
- diffuse effects
- brainstem
75
4 major monoamine neurotransmitters
- dopamine
- epinephrine
- norepinephrine
- serotonin
76
plays a crucial role in various brain functions
dopamine
77
neurons releasing epinephrine
adrenergic
78
neurons releasing norepinephrine
noradrenergic
79
also called 5-Hydroxytryptamine or 5-HT
serotonin
80
serotonin is synthesized from what amino acid
tryptophan
81
serotonin is classified as ____
indolamine
82
a unique small-molecule neurotransmitter
acetylcholine
83
where is acetylcholine found?
- neuromuscular junctions
- autonomic nervous system synapses
- central nervous system synapses
84
neurons releasing acetylcholine
cholinergic
85
two classes of unconventional neurotransmitters
- soluble-gas neurotransmitters
- endocannabinoids
86
- Produced in neural cytoplasm and diffused through cell membranes
- Regulate presynaptic neuron activity, involved in retrograde transmission
soluble-gas neurotransmitters
87
synthesized from fatty compounds
endocannabinoids
88
examples of endocannabinoids
- anandamide
89
examples of soluble-gas neurotransmitters
- nitric oxide
- carbon monoxide
90
approx number of neuropeptides that were identified
100
91
actions of neuropeptides depend on
amino acid sequences
92
5 categories of neuropeptides
- pituitary peptides
- hypothalamic peptides
- brain-gut peptides
- opioid peptides
- miscellaneous peptides
93
Originally identified as pituitary hormones
pituitary peptides
94
First identified as hypothalamic hormones
hypothalamic peptides
95
initially discovered in the gut
brain-gut peptides
96
structurally similar to opium components
opioid peptides
97
A catch-all category for others.
miscellaneous peptides
98
explores the influence of drugs on neurotransmitter systems and their impact on behavior
pharmacology of synaptic transmission and behavior
99
key players in brain function and behavior
neurotransmitters
100
can either facilitate or inhibit synaptic transmission
drugs
101
enhance neurotransmitter effects
agonists
102
inhibit neurotransmitter effects
antagonists
103
steps of neurotransmission
- Synthesis of the neurotransmitter.
- Storage in vesicles.
- Breakdown of leaked neurotransmitter in the cytoplasm.
- Exocytosis of neurotransmitters.
- Inhibitory feedback via autoreceptors.
- Activation of postsynaptic receptors.
- Deactivation of neurotransmitters.
104
bind to postsynaptic receptors and activate them
agonists
105
bind to postsynaptic receptors without activating them, blocking access to the neurotransmitter
antagonists
106
3 influential lines of research in behavioral pharmacology
- discovery of Receptor Subtypes:
WRINKLES AND DARTS
- discovery of Endogenous Opioids: PLEASURE AND PAIN
- discovery of Antipsychotic Drugs: TREMORS AND MENTAL ILLNESS
107
found at motor neuron-muscle fiber junctions in the PNS
nicotinic receptors
108
abundant in the autonomic nervous system (ANS)
muscarinic receptors
109
Nicotinic receptors are _____, while muscarinic receptors are _____
- ionotropic
- metabotropic
110
an extract used by South Americans, is a nicotinic receptor blocker, paralyzing by blocking neuromuscular junction transmission
curare
111
a neurotoxin, is a nicotinic antagonist, inhibiting acetylcholine release at neuromuscular junctions
botox
112
obtained from opium poppy seed pods, used for pleasurable effects throughout human history.
opium
113
a major psychoactive component of opium, is addictive but also serves as an effective painkiller
morphine
