-
In neurons, electrical signals are carried by movement of?
Iona
-
Charged particles such as Na or K can pass across lipid bilayers?
Only if ions channels or transporters are present
-
In Neuro, the symbol q in Ohm?s law stands for _______ and represents_______
Conductance; presence of available ion channels
-
The formation of NA and K concentration gradients in cells depends on ________?
ATP hydrolysis
-
An artificial cell consisting of a bubble-like sphere made from a phospholipid bilayer (no membrane proteins) of 10um diameter is suspended in a large tank contains saltwater NACL 150mM. Inside of the cell contains 15mM NaCl. If an electrode attached to a voltmeter were used to measure the membrane potential of this cell, what would it read?
0mV
-
Carried over from a previous question. If a Na channel was opened up but not Cl what would the membrane potential be at equilibrium?
62mV
-
Carried over again from those questions at equilibrium what would the Na concentration be?
15mM
-
In real live resting cells adding extra cellular Na can drastically alter?
- The resting potential
- What exactly is propagating down the length of an axon during an action potential?
- A wave of changing membrane potential.
-
In the inner ear, specialized neurons called hair cells are bathed in anunusual extra cellular fluid called endolymph. Endolympoh is unusual because its K concentration is unusually high. Which direction is the driving force?
Inward
-
During an action potential in a typical axon, the inward current is primarily through which type of protein?
Voltage-gated Na channel
-
During the action potential in a typical axon the outward current is primarily though which type of protein?
Delayed rectifying voltage-gated k channels.
-
Membranes have passive electrical behaviors called _____ that describe how fast or how far membrane potentials can change.
Cable properties
-
If we were to compare two axons, one of which has a much larger diameter but otherwise identical to the other axon, how would the value of the time constant be different compairing the two?
Axon diameter does not substantially affect the time constant
-
If we were to compare two axons, one of which has a much larger diameter but otherwise identical to the other axon, the larger axon would have a larger constant compared to the smaller axon. What function consequence does this have?
Membrane depolarization passively propagate father in the larger axon compared to the smaller axon in the same amount of time.
-
In Ryder for vertebrate neurons with thin axons to have fast transmission of action potentials, specialized glial cells form structures called myelin sheaths around the axons. This called myelination. Myelination _____ and _______.
Increase time constant and does not change length constant.
-
On a myelinated axon where would you expect to fine voltage-gated Na channels?
At nodes of Ranvier
-
Where are neurotransmitters stored immediately prior to their release into the synaptic cleft?
In Synaptic vesicles
-
Comparing voltage-gated channels and voltage gated Ca channels that we have discussed so far in class, which would be false?
NA fast and CA slow
-
In most cases the primary role of CA at the presynaptic membrane/axon terminal is?
To activate the vSNAre/tSNARE complex
-
Dopamine is a neurotransmitter that functions in a neural pathway in a region of the brain Calle the ventreal regimental area VTA. The VTA is critical in brain mechanisms involved in reward, reinforcement, and emotional arousal. Cocaine works by blocking the function of a protein called the dopamine reap take transporter DAT. What is the consequence of blocking DAT function?
Dopamine levels in the synaptic cleft will increase.
-
Which statement regarding ionotropic receptors is incorrect?
They are always excitatory
-
Ionotropic acetylcholine receptors (also called nicotinic receptors) are permeable to both Na+ and K+. Do ionotropic acetylcholine receptors carry excitatory or inhibitory currents, and why?
Usually excitatory; typically Na+ has a greater driving force inward than the driving force for K+ outward.
-
Glutamate is an excitatory neurotransmitter that activates ionotropic receptors. If glutamate is applied to a glutamatergic synapse, an excitatory postsynaptic potential (EPSP) occurs. What happens if more glutamate is applied?
-
The EPSP gets bigger
- Which statement regarding metabotropic receptors is incorrect?
- They are ion channels
-
-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors are a type of glutamate receptor in the central nervous system. From the name you can guess that AMPA is likely to be _______________.
A drug that targets this specific type of glutamate receptor
-
there is an artificial cell consisting of a bubble-like sphere made from a phospholipid bilayer of 10 m diameter containing fifty K+ leak channels (no other proteins present). The cell is suspended in a large tank containing 5 mM KCl. The inside of the cell contains 100 mM KCl. At 37 oC, you measure the membrane potential Vm = -80 mV. Is there ant net K movement in this system and why?
No; there is no K driving force
-
there is an artificial cell consisting of a bubble-like sphere made from a phospholipid bilayer of 10 m diameter containing fifty K+ leak channels (no other proteins present). The cell is suspended in a large tank containing 5 mM KCl. The inside of the cell contains 100 mM KCl. At 37 oC, you measure the membrane potential Vm = -80 mV.what would happen f ou increased the extra cellular K concentration?
Vm would become more positive
-
there is an artificial cell consisting of a bubble-like sphere made from a phospholipid bilayer of 10 m diameter containing fifty K+ leak channels (no other proteins present). The cell is suspended in a large tank containing 5 mM KCl. The inside of the cell contains 100 mM KCl. At 37 oC, you measure the membrane potential Vm = -80 mV. To this system we add the following: 1 NA channel, 150 mK NaCl extracellular and 15mM NaCl intracellular. Which of the following statements is most accurate?
Compare to the NA channel before the membrane potential Vm increases substantially
-
In a typical neuron, current is injected at the axon hillock to drive the membrane potential to -50 mV. A little distance away from the axon hillock you record Vm on the axon. What is the value of Vm?
-65mV
-
Multiple sclerosis is an autoimmune disease that affects the glial cells that form myelin sheaths. If a neuron that is normally myelinated loses its myelin sheath, what would you expect would happen?
Action potentials will travel down axons more slowly or not at all
-
As voltage-gated Ca2+ channels open in the presynaptic membrane, which of the following is likely to occur?
Nothing was correct in this one
-
If a presynaptic neuron fires action potentials more rapidly, this causes an ____________ in the excitatory postsynaptic potential (EPSP). This is called _____________ summation.
Increase;temporal
-
If multiple presynaptic neurons all synapse onto the same postsynaptic neuron, and these presynaptic neurons all fire action potentials at the same time, this causes an ___________ in the EPSP. This is called ___________ summation.
Increase;Spatial
-
How did the article demstrate that PKD2L1 are responsible for the taste of CO2
They found that mice that had defective sweet, umami, and bitter sensations still responded to CO2, but mice that had defective sour sensation no longer responded to CO2
-
Even though CO22 is detected by sour-detecting taste cells, our perception of CO2 is distinctly different than cour. This suggests that other sensory functions such as mechanosensation are also used to distinguish between CO2 and sour. Based on your understanding of the organization of sensory systems, which cells are the most likely to uniquely respond only to CO2 and not sour?
Neurons in the cortex
-
Which gene knockout would have no effect on a mouses ability to detect CO2?
T1R3
-
Which molecules will NOT trigger a receptor potential in sour-detecting taste cell?
HCO3
-
There may be other carbonic anhydrase enzymes other than Car4 in taste cells. These carbonic anhydrase enzymes do not nessarily have to be expressed on sour-detecting cells. Why?
Because they are broken down into HCO3 and H. The protons can diffuse from the surface of one cell to another.
-
A new organism has only 10 olfactory proteins. How many different odors can this animal distinguish?
1000
-
Same new animal with 10 olfactory proteins. How many different types of olfactory receptor neurons would you expect this animal to have?
10
-
Same new animal with 10 olfactory proteins. Although this animal only has 10 different types of olfactory receptor proteins, it has pretty sensitive sense of smell. This is, it can smell odors at low concentrations. Based on what you know about animals with sensitive senses of smell, approximately how many total number of olfactory receptor neurons would you expect the animal to have?
10,000,000
-
Same cool animal with 10 proteins. How many different types of bulb glomeruli would you expect this animal to have?
10
-
To a first approximation, how many different neuronal firing patterns might you detect in the olfactory cortex.
?
-
Photoreceptors hyperpolarize in response to light. THis is because the rhodopsin signaling cascade.
Activates cGMP phosphodiester asl, which decreases cGMP levels and closes cGMP-gated cation channels.
-
Retinal is the cofactor molecule derived from vitamin A that binds to the GPCR opsin in photoreceptors. Where might you find retinal?
In the lumen of disk membrane
-
The drug viagra is commonly used to treat erectile dysfuntion. Its side effect can effect vision. What can it do to the photoreceptors?
It causes sensitivity to light by increasing membrane potential.
-
How do bipolar off cells generate responces to the same output of a photoreceptor?
Bipolar ON and OFF cells use different receptors.
-
What is the least possible number of synapses between a photoreceptor and a layer IVC spiny stellate cell in the striate cortex?
4
-
Retinotopy describes?
Maintenance of the relative position of ganglion cells and their neighbors to their LGN targets and their neighbors.
-
Orientation columns in the striate cortex refers to:
Columns of cells oriented orthogonally to the surface of the cortex with simple receptive fields oriented in the same direction
-
Parvocellular LGN neurons have small receptive fields. Does this make these neurons contribute to more spatial resolution or less spatial resolution.
More resolution. Each receptive field is smaller, more receptive fields are used to form an image.
-
The medial superior temporal area (also called area MT) of the brain contains neurons with receptive fields that are primarily sensitive to motion. They receive input from the striate cortex; area MT is considered a "higher" visual area. Based on your understanding of receptive fields and their organization, which statement is most likely to be true?
Area MT neurons probably receive spatially summated input from striate cortex neurons with orientation-sensitive receptive fields.
-
Which structure vibrates in the inner ear vibrates in response to sound waves htting the tympanic membrane?
the basilar membrane
-
How are hair cells in the inner ear depolarized?
Mechanically-gated K + channels open.
-
Phase locking is used for sound frequencies up to around 1000 Hz. At higher frequencies, tonotopy is used. The note "concert pitch A", or 440 Hz, is commonly used to tune instruments in an orchestra or musical ensemble. If an instrument is playing concert pitch A, how fast are action potential spikes in the auditory nerve?
440 Hz
-
Let's say that the maximum firing rate for the auditory nerves that receive input from the hair cells is 1000 Hz. The maximum frequency range for human hearing is around 20 kHz (20,000 Hz). If a 20 kHz sound is played, how fast are action potential spikes in the auditory nerve?
1000 Hz
-
The musculoskeletal system is comprised of
Fulcrums and levers
-
Antagonistic pairs of muscles reciprocally contract or relax to generate
- Flexion or extension
- Muscle fibers are innervated by lower mottor neurons located in the ventral horn of the
- Spinal cord
-
Alpha motor neurons are lower motor neurons that innervate
extrafusal muscle fibers
-
is an alpha motor neuron (MN) and all the muscle fibers it synapses to.
a motor unit
-
is all the alpha MNs that innervate a particular muscle as defined anatomically.
a motor neuron pool
-
Alpha motor neurons receive both proprioceptive and
CNS input
-
The neuromuscular junction (NMJ) is an exceptionally large and
reliable synapse
-
in muscles Action potentials propagate down the sarcolemma and
T-tuble membranse
-
is a cytoskeletal structure that functions as the basic unit of muscle contraction
the sarcomere
-
Muscle contraction occurs when thick and thin filaments
slide against each other
-
Ca2+ binding to ________reveals myosin motor head binding sites on the actin thin filament
troponin
-
The muscle spindle is a proprioceptive organ that contains
intrafusal muscle fibers
-
Fast myelinated Ia axons detect muscle spindle shortening and drive the
myotactic reflex
-
is an example of the myotactic reflex in action
knee jerk
-
are lower motor neurons that innervate intrafusal muscle fibers
gamma motor neurons
-
Gamma and alpha motor neurons fire together to keep the muscle spindle taut when
muscles contract
-
The Golgi tendon organ is another
proprioceptive organ
-
detect and prevent excess tension via the reverse myotactic reflex\
lb axons
-
inhibit alpha motor neurons via an inhibitory interneuron in the reverse myotactic reflex
lb axons
-
The myotactic reflex necessarily inactivates antagonist muscles via an
inhibtory neuron
-
Proprioceptive organs in muscles help prevent unwanted
stretching and tension
-
Many reflex loops occur strictly in the spinal cord and do not require
brain input
-
directly controls muscle twitches
primary motor cortex M1
-
in M1 directly control pools of motor neurons
layer V pyramidal neurons (upper motor neurons)
-
connects upper motor neurons to lower motor neurons in the spinal cord
corticospinal tract
-
The supplementary and pre-motor areas (SMA and PMA) in Area 6 control
complex movements
-
The basal ganglia innervates the VL nucleus of the thalamus, which innervates
area 6
-
The cortex innervates the
basal ganglia
-
are coded by firing rate of M1 upper motor neurons
direction vectors
-
are multipotent stem cells that proliferate and differentiate to form neural precursor cells
radial glial cells
-
Partitioning of Notch/Numb proteins during radial glial cell divisions regulates
neural/stem cell fate
-
Neural precursor cells undergo________ along the process of radial glial cells
radial migration
-
Differentiation of neuroblasts depends on semaphorin 3A secreted from
the marginal zone
-
Underlying input from the thalamus is required for normal
cortical differntiation
-
Developing neurites extend to their synaptic targets using
growth cones
-
Axons fasiculate through cell adhesion molecules (CAMs) and interact with the ECM through
integrins
-
Pathway selection during deccusation is controlled by chemo-attractive and repulsive cues from
the midline
-
Growth cones release signals to the target cell to recruit neurotransmitter receptors during
synaptogenesis
-
Neurotrophic factors such as neurotrophins are limiting for neuron survival and prevent
apoptosis
-
Activity-dependent synaptic rearrangement is the final step in
address selection
-
in the LGN segregate left-right inputs during development in an activity-dependent fashion
hebbian synapses
-
More visual system review: LGN afferents first synapse with neurons in layer ____ of the striate cortex, which then synapse with neurons in layer _____.
IV, III
-
leads to permanent loss of stereoscopic vision
strabismus
-
Noradrenergic input from the locus coeruleus is required for
ocular dominance shifts
-
Ca2+ influx through the NMDA receptor only occurs when both pre- and postsynaptic neurons
depolarize
-
Ca2+ recruits AMPA receptors to the postsynaptic membrane, resulting in
long-term potentiation
-
Regulation of synaptic plasticity at glutamatergic excitatory synapses depends on ______ ions flowing through _____ receptors
Ca2+, NMDA
-
influx through NMDA receptors is critical!
CA2
-
are two types of nonassociative learning that form procedural memories
habituation and sensation
-
Early studies showed that procedural memories are are present in simple animals like
aplyasia
-
Sensitization of the gill withdrawal reflex occurs at
the synapse
-
is a form of associative learning that requires careful timing of a CS and US
classical conditioning
-
is a type of associative learning that pairs behaviors with rewards or punishments
instrumental conditioning
-
Video games are _______that leverage instrumental learning mechanisms in humans
Skinner boxes
-
Medial temporal lobectomy prevented patient H.M. from forming new
declarative memories
-
The hippocampus in the medial temporal lobe is involved in
memory formation
-
The hippocampal Schaffer collateral CA3-CA1 synapses are a molecular model for
learing and memory
-
The hippocampus of the medial temporal lobe specifically is required for
spatial memory
-
activates protein kinase C (PKC) and Ca2+-modulated kinase II (CaMKII)
CA2
-
AMPA receptor phosphorylation increases
ionic conductance
-
activity increases AMPA receptor trafficking to the membrane
Kinase
-
increase in size after LTP, presumably due to increased AMPA receptor trafficking
dendritic
-
is a transcription factor involved in memory consolidation
CREB-1
-
Long term depression (LTD) is induced by low frequency
tetanus
-
Different intracellular levels of Ca2+ activate enzymes with
opposing activity
-
The Purkinje cells of the cerebellum are a vertebrate model of
associative motor learning
|
|