midterm 2 Flashcards
1
Q
effects of cocaine
A
psychoactive effects; stimulant (inc BP, HR); at synapses, blocks reuptake transporters for dopamine, norep. ; sympathomimetic ; overstimulates CNS and autonomic
2
Q
what are the effects of stimulants such as amphetamine at synapses
A
mess with transporters by letting NTs leak out, but not go bak into synaptic cell → high concentration of stimulants in synaptic cleft
3
Q
what is morphine come from
A
opium from opium poppy
4
Q
1st abt morphine?
A
1st time someone purifed chemical substance from plant and claimed it carried the same properties
5
Q
1st abt heroin
A
first example of chemical derivative of natural occurring substance that altered
6
Q
how come general anesthetics can enter cells
A
are nonpolar enough to go thru membrane
7
Q
psychosis
A
loss of capacity to judge if in reality or not–> hallucinations and delusions
8
Q
schizophrenia
A
when psychosis affects life, chronic psychotic condition
9
Q
how to reduce psychosis maybe
A
dopamine receptor antagonists –> reduce activity in the brain and reduce psychosis
10
Q
how to antidepressants
A
impact on norepinephrine or serotonin
11
Q
monoamine hypothesis of depression
A
dep related to malfunction in certain monoamine NT (esp serotonin)
12
Q
what do psychedelics interact with
A
5-HTzA, a specific serotonin receptor
13
Q
what is schedule one controlled substance
A
no accepted medical use, high potential for abuse
14
Q
Raphael mechoulam
A
discovered psychoactive ingredients in THC in 1960s and promoted importance of doing this kind of science in 60s, 70s
15
Q
prominent cannabinoids
A
THC-A, CBD, THC
16
Q
what THC do
A
psychosomatic - amplifies thoughts and feelings which can be umcomfy, esp for ppl vulnerable to psychoses
17
Q
what CBD dp
A
antipsychotic (opposite of THC)–> decrease in psychotic symptoms
18
Q
cannabinoid receptors
A
found throughout brain and body, one of most abundant NT receptor types; are GPCRs
19
Q
endocannabinoids
A
endogenous substances that are reacting with the cannabinoid receptors; are produced and released by postsynaptic neuron and goes back to presynaptic
20
Q
retrograde signal
A
postsynaptic going to presynaptic (opposite way);
21
Q
neuroplasticity
A
idea that synapses can change in strength , ie how much NT and how long staying in synapse
22
Q
how change synapse strength ie neuroplasticity
A
1 way is by altering voltage gated ion channels;
can alter reuptake transporters, more of these means a weaker synapse;
Can change number of postsynaptic NT receptors;
(can all be mediated by retrograde signals)
23
Q
approximate % transcribed and% translated
A
<3% of human genome codes for functional protein, remaining 97% transcribed into RNA and is all involved in regulating genes
24
Q
embryonic development
A
Day 1: fertilization
→ cell division → embryonic disc (day 15) → neural tube (day 23) which becomes the brain and spinal cord
25
what governs neuron system differentiation
transcription factors- proteins that form complexes sit on DNA and activate transcription of genes
26
process of achieving differentiation of brain cells
Stem cells → neuron system progenitor cell → neurogenesis and gliogenesis occur together w axon and dendrite branching
27
synaptogenesis
includes pruning of synapse, activity-dependent survival, stabilization thru use and destabilization thru disuse (all relates to plasticity)
28
roger sperry experiment
one with eye and the frog
29
chemoaffinity hypothesis
neurons use specific chemical signals to guide their wiring (migration and synaptogenesis) during development
30
nerve growth factors do what
effects in guidance of neurons and wiring, ie chemical guidance in axon growth (contact and soluble factors)
31
chemotaxis
means moving toward chemicals
32
how E coli sense sugar
with flagella (little motors), has chemoreceptor proteins that detect attractants and direct the bacteria --> bias random swim toward attractants by controlling tumbling
33
naïve realism
what we sense is actually what is out there
34
range of human sensitivity to electromagnetic energy spectrum
400-700 nm (visible light)
35
karl von frisch
studied honeybee vision and behavior
36
honeyguide
bees can see UV pattern on flowers, use as bullseye to know where the center of the flower is
37
IR sensing in pit vipers
rattlesnakes and other pit vipers can image IR radiation (with pit organ?)
38
how do night vision devices work
either image intensifiers or show IR/thermal light
39
light polarization
most light is unpolarized but can do things to polarize, meaning cutting out all directions except one
40
how does sunlight become polarized
is initially unpolarized but becomes polarized by bouncing air molecules
41
skylight polarization pattern
sunlight has different polarization based on location/distance from equator --> lots of animals can navigate based on this polarization
42
passive electroreception
detecting electric field associated with something; for example sharks use it to locate animals for food
43
active electroreception
fish is generating stronger electric fields, measuring it and looking for changes or distortion → can have electrocommunication using active electroreception
44
George berkeley
it isn’t possible to have existence out of the minds of thinking things which perceive them (the limit of thought/consciousness)
45
taste vs flavor
flavor includes taste, smell, pungency (spicy/hot), texture
46
5 types of gustatory receptor cells
salt, sour, bitter, sweet, umami
47
what are two main pathways for gustatory receptor cells
1) Tongue → cranial nerves 7,9,10--> brainstem → thalamus → insula → somatosensory cortex
2) Tongue → cranial nerves 7,9,10--> brainstem → hypothalmus → amygdala
48
what are taste buds
Clusters of Receptor cells that begin the tasting process; located in mouth on tongue with a few on upper palate and pharynx; there is a pore that exposes receptor cells to interior of mouth
49
how many taste buds in mouth
~10,000 (and a million receptor cells!)
50
structure of gustatory receptor cell
Ends of receptor cells composed of microvilli and within the membrane of microvilli are taste receptor proteins; at base, is a contact point, a chemical synapse w nerve fibers that respond to NT molecules released by the taste receptor cells
51
how often are gustatory cells replaced
every ~2 weeks
52
how get salt taste
NaCl mostly → Na+ flows thru sodium ion channels in the salt taste receptor cells (conclusively identified)
53
how get sour taste
acids, release of H+ in soln; H+ flows thru hydrogen channels in sour taste receptor cells
54
how get bitter taste
many things including plant alkaloids; GPCRs not ion channels; more than 30 different GPCR assoc w bitter taste
55
how get sweet taste
sucrose, glucose, etc ; two GPCRs are linked to form the functional sweet receptor
56
how get umami taste
glutamate/MSG; metabotropic GCPR glutamate receptor
57
types of gustatory receptor proteins
ion channels and GPCRs
58
sweeter-than-sugar sweeteners
Artifical sweeteners: saccharin 300x sweeter than sucrose, also has a bitter taste; aspartame the most widely used 200x sweeter than sucrose; sucralose 600x sweeter “Splenda”
neotme 10,000x sweeter
Non-artificial - steviol
59
what cranial nerves for taste
cranial nerves 7,9,10
60
cranial nerve for spicy signals
cranial nerve 5, spicy hot considered part of pain system not taste system
61
capsaicin
molecule that makes chili spicy
62
capsaicin signaling pathway
binds to receptor protein, opens an ion channel and Ca ions flow into receptor cell→ depolarization→ increased neural excitability
63
GPCR multimer
proteins link together to form different units so they can use responses to one trigger to inform response to others
64
Delbrück’s “Principle of Limited Sloppiness”
idea that the best discoveries have just enough sloppiness to accidentally do something but able to retrace the steps
65
miraculin, miracle fruit
West African berry that makes sour things sweet that binds to sweet receptor GCPRs in very acidic conditions (agonist effects at very low pH)
66
TRPV1
capsaicin receptor, responsible for spicy hot sensation, not just in mouth, all over body
67
TRPV8
responds to cold aka menthol/mint receptor --> produces experience of coolness
68
TRPA1
different kind of spicy hot (mustard, horseradish, wasabi) activated with allyl-isothiocyanate
69
isothiocyanates
mustard, horseradish, wasabi
70
differences in perception of cilantro taste
Some ppl experience leaf as yummy, others experience it as soapy due to more sensitive GPCR receptor
71
structure of eye
on surface of retina, photoreceptor cells, rods and cones; fovea is center of retina
72
rod receptors
contain photoreceptor protein, rhodopsin, and are sensitive to dim light → responsible for dim light vision
73
cone receptors
Cone receptors contain photoreceptor protein, cone-opsin, activated w bright light
74
photoreceptor proteins
rhodopsin and cone-opsin, both are GPCRs activated by light
75
types of cones
3 types of cones (S has peak of 420, M has peak of 530, L has peak of 560)
76
wavelength peak for rods
498
77
how get color in vision?
Different wavelengths activate different cones to varying degrees
78
distribution of photoreceptor cells in retina
Cones are almost all within a 4mm region at center of retina (fovea);
Almost no rods at fovea and increase as go out
None of either at blind spot
79
number of photoreceptor cells
rods (100 million); cones (5 million)
80
how many rhodopsin proteins in one rod cell
up to 100 million --> 10^16 photoreceptor proteins in human eye
81
retinal achromatopsia
loss of all cone cells --> no color vision
82
retinal
light absorbing protein embedded within the photoreceptor protein that starts cascade that leads to neural signal, have to consume retinal, usually in form of beta-carotene (found in carrots), and vitamin A
83
blind spot
a space near the fovea where there are no rods/cone cells and where axons from neurons in the retina form the optic nerve (1E6 nerve cells); not enough space for photoreceptor
84
location of coding for photoreceptor proteins on chromosomes
M,L opsins on X chromosome, S and rhodopsin on non-sex chromosome
85
color anomalous
opsin protein's amino acid sequence slightly changes, altering ability to differentiate between different colors
86
structure of photoreceptor proteins
Both rhodopsin & cone opsin has ~350 aa sequence in a chain embedded in lipid bilayer membrane (crosses 7 times)
87
light-induced isomerization/photoisomerization
when retinal is bound to opsin protein, it is kinked (cis), but adsorption of photom triggers rotation around double bond --> trans and is no longer kinked
88
GPCR intracellular cascade
light absorbed by cis retinal, isomerizes to trans form, activating opsin protein & making it available to bind with an intracellular G-protein; G-protein interacts with cGMP & activates it; phosphodiesterase interacts with cGMP to make it noncyclic GMP; GMP’s interaction with certain ion channels keep them open until concentration decreases, altering the membrane potential and change amt of NT released at synapse
89
3 layers of retina
photoreceptor cells, bipolar cells, ganglion cells
90
bipolar cells
form synapses with rods & cones & bipolar form synapses with ganglion cells, which then send info to the brain
91
ganglion cells
Ganglion cell axons bundle together to form optic nerve, 1E6 ganglion cells
92
pathway from eyes to brain
eye--> optic nerve--> optic chiasm-->(90% go to)thalamus-->LGN-->posterior occipital lobe where form synapses with cortical neurons
93
contralateral connectivity
right side of brain receiving info from left visual space; left side of brain receiving info from right visual space
94
what part of brain is responsible for analysis of visual information
visual cortex - occipital lobes and posterior regions of the temporal lobes
95
visual cortex
region of the brain that analyzes visual info: info first enters V1 in posterior occipital lobe, then cells in V1 send xons to nearby V2-V5 (highly interconnected); many neurons in visual cortex also send axons back to the LGN
96
what do specific visual areas respond to?
V1: mostly responds to contrast (edges + space); V4: specific colors; V5: movement
97
superior colliculus
part of midbrain that 10% of optic nerve axons enter; heavily involved in rapid responses to sensory stimuli that don’t involve awareness
98
scotoma
blind spot in a specific region of space, caused by a lesion in V1
99
hemianopsia
loss of vision in one half of visual space
100
cortical achromatopsia
washed out/faded color perception caused by lesion in v4
101
akinetopsia
motion blindness, caused by lesion in V5
102
prosopagnosia
person has difficulty recognizing faces caused by lesion in post temporal lobe
103
agnosia
struggle with recognizing all or nearly all visual objects
104
receptive field of a cell
region of space from which stimulants elicit neural response
105
blindsight
ppl surprisingly good at guessing things despite being in a blindspot; knows but isn't aware
106
sound waves caused by
changes in density, pressure of air molecules
107
relationship bt frequency and wavelength
higher the frequency, shorter the wavelength; lower frequency = longer wavelength
108
higher pitch or tone due to
higher frequency
109
loudness associated with
amplitude or magnitude
110
human hearing range
20-20,000 Hz
111
speed of sound
1100 ft/s, 335 m/s, 750 mph
112
timbre
complexity of sound waveform beyond pure tone
113
joseph fourier and fourier analysis
can get any complex waveform from a sum of simple sine waves
114
inner ear consists of
cochlea, semicircular canals = bony labyrinth, filled with fluid that vibrates
115
basilar membrane
runs down length of cochlea and also vibrates; has varying thickness that corresponds to different frequencies
116
where are hair cells
along length of basilar membrane
117
roughly how do hair cells get signals to brain
As cilia swoosh from vibration, the cells form chemical synapses w fibers of the auditory nerve, cranial nerve 8, sending info to brain
118
hairs intracellular pathway
Hairs connected by tiny molecular cables which are coupled to positive ion channels, as hairs bend, cables tug on channels and open them → K+ flow into hairs = depolarization of hair cell’s membrane potential → voltage gated Ca channels open → Ca++ flows into cell → NT release etc
119
inner vs outer hair cells
Inner hair cells( about 3500 in each ear) are ones more involved in sending signals to brain; outer hair cells receive more input from the brainstem, also involved in changing sensitivity of basilar membrane
120
auditory neural pathway into brain
NT released from hair cell→ cranial nerve 8 which are clustered in spiral ganglion, are bipolar neurons, single dendrite gets signal and a single axon sends into brainstem→ synapse w cells in cochlear nucleus→ regions of the pons called superior olive and lateral lemniscus→ inferior colliculus in midbrain→ MGN of thalamus→ primary auditory cortex, A1
121
different causes of hearing loss
infection, genetics, noise-induced
122
vestibular system
Detects our orientation relative to gravity and our acceleration as we move, walk, turn;
Consists of 3 semicircular canals, and two cavities - utricle and saccule
123
what do utricle and saccule do
Contain receptor cells that detect the movement of fluid in the attached semicircular canals
124
otolith
Tiny microscopic stones, “ear stones” suspended in the fluid above the hair cells ; contribute to us being able to balance
125
olfactory receptor cells
embedded in nasal epithelium, have cilia on ends
126
cilia (olfactory)
On the ends of olfactory receptor cells, extend into mucus lining of nasal passage, large surface area that contain olfactory receptor proteins
127
olfactory receptor proteins
GPCRs, many different types, humans have ~350; can discriminate large number of smells bc a certain odorant will bind to multiple proteins at varying degrees
128
pseudogene
Nonfunctional genes that appear to code for olfactory GPCRs but do not code for functional proteins
Have about 600
Speculated that we used to have more sophisticated sense of smell
129
essential oil
Oily concentrate of aromatic molecules from a plant
Oily bc aroma carrying molecules are usually hydrophobic
Often prepared by distillation
130
aromas
comprised of dozens of different molecules activating various combos of olfactory receptor proteins to create a specific smell experience
131
molecules assoc w lemon and rose
lemon - geranial
| rose- geraniol
132
sulfur, thiols
thio refers to element sulfur, thiol refers to -SH group; stinky; some found in asparagus pee
133
specific anosmia
loss of sensitivity to a specific kind of smell, most likely caused by genetic variation in one of the proteins
134
general anosmia
loss of sensitivity to a large variety of aromas, in some cases even a complete lack of olfactory sensitivity; variety of causes including nasal congestion, head trauma, brain disease, developmental factors
135
hyperosmia
increased sensitivity to odors
136
intracellular pathway for olfactory cell
Activation of an olfactory GPCR initiates an intracellular cascade → synthesis of cAMP→ interacts with cation channel that is gated by the binding of cyclic nucleotides → influx of Ca++ and Na+ → depolarizes cell and generates signal
137
pathway from olfactory to brain
receptor cell--> cranial nerve 1 → olfactory bulb where axons form synapses with dendrites of mitral cells → send axons to pyriform cortex (and to amygdala for other nasal passage??, in the limbic system) → pyriform sends axons to thalamus → makes connections to orbitofrontal cortex of frontal lobe , also interconnections with hippocampus and hypthalamus
138
olfactory bulb
where olfactory receptor cells send axons, located above and adjacent to nasal cavity in humans
139
cranial nerve for olfactory
cranial nerve 1
140
pheromonones
chemicals that carry signal info related to social communications bt members of the same species, gen thought to elicit innately programmed behaviors
141
vomeronasal system
responds to pheromones
142
somatosensory receptors
dendrites of somatosensory neurons terminate in top layers of skin and these have receptor proteins that respond to touches, pokes, delta T
143
dorsal root ganglia (DRG)
clusters of cells near the spinal cord; this is where the cell bodies for nerve fibers are
144
wilder penfield
discovered the first somatosensory body maps in humans undergoing brain surgery; Penfield stimulated various regions of cerebral cortex in patients undergoing surgery; listened to how patients described their associated experiences & able to build somatosensory map of the body
145
somatosensory body map
directory of the spacial receptive fields of neurons/DRG synapses and how it is associated with a specific location of the somatosensory cortex in the parietal lobe
146
S1
primary somatosensory cortex - topographic representation of somatosensory space; lesions mean loss of sensation in a particular region related to where lesion is on body map in S1
147
neglect syndrome
when touch sensation is intact but usually ignored or not recognized until attention is specifically drawn to it
148
M1 (primary motor cortex)
controls most motor functions, a body map of neurons that send out signals that initiate contraction of skeletal muscles; when signals propagate via spinal cord and eventually arrive at synapses with muscles
149
apraxia
disorder in the organization of movement
150
mirror neurons
neurons in the premotor area that are active during particular movements or when these movements are observed in another person
151
cerebellum
involved in the regulation of movement; wrapped around the brain stem & is densely packed with neurons and neural connections (>50billion); involved in timing+coord of movement
152
anosognosia
the lack of knowledge about one’s own disease; deny that there is something wrong with them; happens when right hemisphere lesion in stroke
153
whisker barrel expansion
corresponding cells to amputated whisker help the cells for surrounding whiskers
154
phantom limb
the feeling of having a limb that is no longer there; especially prevalent in people who had severe injuries on limb before amputation; found that touching face relates to touching phantom limb because of sensory map has axons for face near arms
155
supplementary motor areas do what?
Organized + plan movements before things signalled in M1
156
human genome
3x10^9 nucleotide base pairs coding for 21k proteins
157
neural progenitor cells
create neurons (neurogenesis) and glial cells (gliogenesis)
158
growth cone
growth at end of axon with extensions (filopedia) & whose growth is propelled by the cytoskeleton’s actions
159
cytoskeleton
dynamic, made of elaborate ordered arrays of protein polymers made of (microtubles (tubulin protein) & microfilament (actin)
160
microfilaments and microtubules
form long strands within cel that perform functions like: growth/movement of cell processes, moving materials, inserting/removing membrane proteins
161
hippocampus
primary location where adult neurogenesis happens, 1400 new neurons added each day
162
1st growth factor
NGF
163
olfactory in brain
frontal lobe
164
what lobe is somatosensory in
parietal
