Term
hammer tap on the knee causes you to contract _______ & relaxation _______ |
|
Definition
quadricep muscle; hamstring muscle |
|
|
Term
does a reflex involve the cortex? |
|
Definition
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|
Term
why don't you get any movement but just are bulging the muscles when you flex (think body builder)? |
|
Definition
you're contracting both muscles |
|
|
Term
how do all neural structures start? |
|
Definition
|
|
Term
2 main places sensory cortices receive sensory input from |
|
Definition
1. entorhinal cortex 2. visual cortex |
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|
Term
motor cortex sends descending motor commands to which 2 places to move skeletal muscles? |
|
Definition
1. spinal cord 2. lower motor neurons |
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|
Term
after a movement, you get _______ feedback into the spinal cord circuits |
|
Definition
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|
Term
do we have a homunculus for the motor cortex? |
|
Definition
yes (just like sensory cortex) |
|
|
Term
difference between corticobulbar tract vs corticospinal tract |
|
Definition
corticobulbar = face
corticospinal = upper extremity, trunk, lower extremity |
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|
Term
what was learned from the experiment where they stuck an electrode in the brain to record single neuron spiking & EMG recording muscular responses in hand (done in monkeys) |
|
Definition
you can align action potentials from the brain recording with the EMG ramping recorded from the muscles |
|
|
Term
do we have topology in lower motor neurons in the spinal cord? |
|
Definition
yes! (it's not just in the brain!) |
|
|
Term
difference between proximal muscles vs distal muscles in terms of their organization in the spinal cord |
|
Definition
proximal = more medial in spinal cord
distal = more lateral in spinal cord |
|
|
Term
what happens to the somatotopic organization of lower motor neuron pools as you go down the spinal cord? |
|
Definition
you are also moving down your body with which muscle groups are represented |
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|
Term
motor neuron (called alpha motor neuron in spinal cord) releases ______ as primary neurotransmitter |
|
Definition
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|
Term
why can you apply an electrical signal onto your muscle & cause yourself to move without actually using your cortex to do so? |
|
Definition
motor units are electrical units |
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|
Term
list the three different types of motor units from highest to lowest force |
|
Definition
1. fast fatigable 2. fast fatigue-resistant 3. slow |
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|
Term
what is the trade off in terms of using the different muscle types? |
|
Definition
how much force a muscle type can give you vs how long they can stay working |
|
|
Term
why do people believe that older marathon runners are better at this long distance stuff but might not be as good at sprinting? |
|
Definition
they have more fast fatigue-resistant muscles |
|
|
Term
which motor neurons are usually only activated when a large amount of force is required? |
|
Definition
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|
Term
why do people who work out look more toned? |
|
Definition
people who work out more usually have better innervation of their muscles...these muscles are activated at any given amount of time |
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|
Term
normal vs extensor plantar response (example of sensorimotor reflex) |
|
Definition
normal: touching of the bottom of foot --> toes down (flexion)
extensor: touching of the bottom of foot --> fanning of toes (Babinski sign) |
|
|
Term
|
Definition
understanding of where your body is in space |
|
|
Term
what kind of signals tell your body how much you need to flex to hold something in a specific place in space? |
|
Definition
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|
Term
2 instances in which golgi tendon organs are important due to their role in negative feedback regulation of muscle tension |
|
Definition
1. if you catch something too heavy 2. if you catch something too light |
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|
Term
is there need for descending input when you're walking? |
|
Definition
no! (you're not really consciously thinking about how you're walking) |
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|
Term
cat experiment demonstrating cortical descending input isn't necessary for walking |
|
Definition
experimenters disconnected brain from spinal cord, but if you put the cats on a treadmill they actually would naturally move to walk! |
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|
Term
how were tuning of certain motor neurons for movement to specific places discovered? |
|
Definition
monkey experiment: he looks to see where a light lights up & then moves his cursor to where the light is shining |
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|
Term
most simple kind of network |
|
Definition
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|
Term
"attractor" relationship between two neurons |
|
Definition
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|
Term
"self inhibition" network |
|
Definition
excitatory neuron excited an inhibitory neuron that feeds back onto it to inhibit the initial neuron |
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|
Term
"mutual inhibition" network |
|
Definition
excitatory neurons excite inhibitory neurons that inhibit the other excitatory neurons |
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|
Term
can neurons have spontaneous firing? |
|
Definition
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|
Term
are all synapses of equal strength? |
|
Definition
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|
Term
"recurrent innervation" network |
|
Definition
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|
Term
2 examples of how upper motor neurons are directional & also limb specific |
|
Definition
1. left side of the brain tends to control the right side of the body 2. neurons can actually be inhibited in opposite direction from its preferred direction |
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|
Term
magnitudes of various neuronal responses at different direction angles allows you to make _______ |
|
Definition
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|
Term
what is the train of thought behind brain computer interface (BCI)? |
|
Definition
if we can use tuning curves to decode a motor signal, we can have computer output a motor command to a machine to move something |
|
|
Term
6 steps in stretch reflex circuitry that helps you adjust when holding something surprisingly heavy (for example) |
|
Definition
1. descending facilitation & inhibition 2. alpha motor neuron 3. muscle (puts out the force required to hold glass) 4. disturbance (addition of liquid to glass...causes a length change in muscle fiber) 5. spindle receptor (disturbance causes an increase in spindle afferent discharge) 6. alpha motor neuron for adjustment |
|
|
Term
our initial motor command to pick something up comes from ______ |
|
Definition
our IDEA of how heavy something is going to be |
|
|
Term
equation for Bayesian inference |
|
Definition
P(belief | sensory input) = [P(sensory input | belief) * P(belief)] / P(sensory input) |
|
|
Term
probability vs Bayesian probability |
|
Definition
probability: often used to refer to frequency
Bayesian probability: a measure of a state of knowledge |
|
|
Term
what does Bayesian probability quantify |
|
Definition
|
|
Term
|
Definition
P(A|B) = [P(B|A) * P(A)] / P(B) |
|
|
Term
in Bayes' theorem, "A" means _____ |
|
Definition
prior hypothesis or belief |
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|
Term
in Bayes' theorem, "B" means _____ |
|
Definition
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|
Term
Bayes' theorem: long hair, bathroom line example
A = ? |
|
Definition
belief that you are looking at a woman |
|
|
Term
Bayes' theorem: long hair, bathroom line example
B = ? |
|
Definition
|
|
Term
2 reasons why Bayesian probability is useful |
|
Definition
1. it allows us to put probability values on unknowns 2. this can show counterintuitive results - e.g. that the disease test may not be useful |
|
|
Term
3 things we need in addition to sensory inputs to make decisions |
|
Definition
1. memory 2. models 3. cognitive circuits |
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|
Term
what do cells in a circuit perform computations between to decide how to enact different results? |
|
Definition
sensory input & memory of how things normally are |
|
|
Term
is the BG thought of as a singular unit in the brain or as a plurality of things? |
|
Definition
singular unit (even though the word is plural) |
|
|
Term
how do we interact with the ever-changing world? |
|
Definition
|
|
Term
|
Definition
1. supervised 2. unsupervised 3. reinforcement |
|
|
Term
6 steps in the agent flow of learning |
|
Definition
1. receives state 2. follows policy 3. selects action 4. obtains reward 5. transitions state 6. repeat |
|
|
Term
|
Definition
maximize potential long-term gain |
|
|
Term
BG: cortex --> excitatory onto ______ |
|
Definition
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|
Term
BG: GPi/SNr --> inhibitory onto ______ --> excitatory back onto ______ |
|
Definition
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|
Term
are projection neurons from the basal ganglia inhibitory or excitatory? |
|
Definition
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|
Term
two pathways in basal ganglia activated by the motor plan |
|
Definition
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|
Term
is the striatum a pretty large or pretty small area of the brain? |
|
Definition
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|
Term
how are the direct & indirect pathway neurons arranged in the striatum? |
|
Definition
|
|
Term
how do the direct/indirect pathways interact in the BG? |
|
Definition
act to keep each other in check |
|
|
Term
in primates, the BG is called the _______ |
|
Definition
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|
Term
dopaminergic input for the BG comes from the ________ onto the caudate/putamen (AKA striatum) |
|
Definition
substantia nigra pars compacta |
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|
Term
SNR has a high firing rate, tonic activity --> projects _______ onto the thalamus (as well as other areas) |
|
Definition
|
|
Term
difference between glutamatergic vs GABAergic |
|
Definition
glutamatergic = positive
GABAergic = inhibitory |
|
|
Term
direct pathway neurons: _______ dopamine receptor |
|
Definition
|
|
Term
indirect pathway neurons: _______ dopamine receptor |
|
Definition
|
|
Term
does the BG project to downstream motor nuclei? |
|
Definition
|
|
Term
does dopamine cause a cell to fire or to be inhibited? |
|
Definition
|
|
Term
if the striatum is at rest, is there excitation of motor cortex? |
|
Definition
no (globus pallidus is tonically active --> thereby inhibiting the thalamus) |
|
|
Term
why is the motor cortex excited if the striatum is transiently excited? |
|
Definition
globus pallidus is transiently inhibited --> thalamus is disinhibited so other inputs can excite it |
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|
Term
how is the caudate involved in eye movement? |
|
Definition
increased caudate activity (direct pathway) --> decrease in SNR activity --> increase in superior colliculus activity --> primate moves its eyes |
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|
Term
|
Definition
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|
Term
2 motor loops BG is involved in |
|
Definition
1. body movement 2. oculomotor |
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|
Term
2 non-motor loops BG is involved in |
|
Definition
|
|
Term
what would happen if we killed off the dopamine input to the BG? |
|
Definition
we would see that the direct pathway drive would be diminished relative to controls & the indirect pathway drive would be increased relative to controls |
|
|
Term
in a PD brain, you can see a lack of black colored cells in the ______ |
|
Definition
|
|
Term
is Parkinson's a basal ganglia disease? |
|
Definition
NO (it is a dopamine circuit disease) |
|
|
Term
|
Definition
electrode brain implant is connected back to generators outside of the brain |
|
|
Term
|
Definition
eliminate physical symptoms of PD such as rigidity, tremors, & bradykinesia |
|
|
Term
2 clinical applications for PD |
|
Definition
1. DBS 2. dopamine replacement therapy (L-DOPA) |
|
|
Term
do we know why DBS works? |
|
Definition
|
|
Term
how is Huntington's disease symptoms different from PD? |
|
Definition
instead of a decrease of movement, you see a lack of "breaking" or an increase in involuntary movement |
|
|
Term
what does a Huntington's brain look like compared to control? |
|
Definition
can literally see a shriveling up of the caudate/putamen |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
direct pathway MSN receptor |
|
Definition
|
|
Term
indirect pathway MSN receptor |
|
Definition
|
|
Term
4 brain regions involved in motor circuits |
|
Definition
1. motor cortex 2. BG 3. cerebellum 4. thalamus |
|
|
Term
|
Definition
feedback signal is reward |
|
|
Term
|
Definition
tells you HOW to do something with an error signal |
|
|
Term
|
Definition
no real feedback on your actions |
|
|
Term
how is the joystick task an example of reinforcement learning? |
|
Definition
we don't tell the animal what it is doing wrong with the reaches when it doesn't get a reward, but when the animal does what we want it gets a reward |
|
|
Term
how would we make the joystick task supervised learning? |
|
Definition
if the animal was given bigger rewards for bigger reaches |
|
|
Term
how is making desired movements a form of supervised learning? |
|
Definition
feedback comes if movement is done wrong (ex. if reaching for something is too far to the side or too high up etc.) |
|
|
Term
how does cerebellar ataxia show symptoms? |
|
Definition
tremors with specific movements |
|
|
Term
general cerebellum functions |
|
Definition
major role in timing of motor activities & in rapid, smooth progression of movements |
|
|
Term
general basal ganglia functions |
|
Definition
helps plan & control complex patterns of movement |
|
|
Term
where is the cerebellum located? |
|
Definition
|
|
Term
how is the cerebellum organized? |
|
Definition
lots of folds & deeper structures (deep cerebellar nuclei) |
|
|
Term
do we have a homunculus representation in cerebellum? |
|
Definition
|
|
Term
does the cerebellum receive many or a few inputs? |
|
Definition
|
|
Term
does cerebellum send feedback back up to motor cortex? |
|
Definition
|
|
Term
is there a cerebellar cortex on each side of the brain? |
|
Definition
|
|
Term
all of the output from the folia (cerebellar cortex) come from _______ cells |
|
Definition
|
|
Term
2 different types of APs from Purkinje cells |
|
Definition
1. simple spikes (normal APs) 2. complex spikes |
|
|
Term
Purkinje cells learn via _____ |
|
Definition
|
|
Term
do parallel fibers have relatively large or small synapses onto the Purkinje? |
|
Definition
|
|
Term
how are climbing fibers organized for synapses with Purkinje? |
|
Definition
wrapped around the large dendrites |
|
|
Term
2 ways climbing fibers decrease Purkinje firing |
|
Definition
1. coincidence with parallel fibers --> LTD 2. huge depolarization --> bit of silent time when it can't fire another AP |
|
|
Term
how does cerebellar folia exposed to alcohol look? |
|
Definition
like there is a lack of cells |
|
|
Term
what does the eye do when viewing a picture? |
|
Definition
the eye actually makes lots of tiny movements in a very specific way |
|
|
Term
do eyes move very quickly or slowly to match a target? |
|
Definition
|
|
Term
what would happen if the brain didn't turn off visual input while you are making a saccade? |
|
Definition
you would feel like your world is always shifting around |
|
|
Term
why does your brain predict what the world should look like when your eyes get to the end of their saccade? |
|
Definition
you are not crazy thrown off when your eyes get there |
|
|
Term
|
Definition
forcing a saccade by pushing the eye |
|
|
Term
|
Definition
1. saccade 2. smooth pursuit |
|
|
Term
metrics of smooth pursuit eye movements |
|
Definition
do a catch-up saccade at initial movement of what you're following, then smooth follow its movement |
|
|
Term
how is feedback involved in smooth pursuit? |
|
Definition
when you're following something, you are getting constant feedback about if you're following it well (or moving your eyes too fast or too slow) |
|
|
Term
eye muscles for up/down movement |
|
Definition
superior rectus/inferior rectus |
|
|
Term
eye muscles for outside/inside movement |
|
Definition
lateral rectus/medial rectus |
|
|
Term
eye muscles for spinning in eye socket |
|
Definition
superior/inferior oblique |
|
|
Term
how do muscles work together to move your eye in one direction? |
|
Definition
that muscle contracts & the opposing muscle relaxes |
|
|
Term
if we were to record from neuron in abducens nucleus that innervates lateral rectus muscle: as we want to move the eye laterally --> ? |
|
Definition
there will be a large increase in firing right before movement |
|
|
Term
if we were to record from neuron in abducens nucleus that innervates lateral rectus muscle: as the eye is wanting to be kept laterally --> ? |
|
Definition
there will be a tonic firing to hold the eye there |
|
|
Term
if we were to record from neuron in abducens nucleus that innervates lateral rectus muscle: if the eye is wanting to be kept medial --> ? |
|
Definition
there will be a decrease in firing |
|
|
Term
how do we get both eyes to move to the right at the same time? |
|
Definition
right PPRF bifurcates & one crosses the midline to innervate both eyes |
|
|
Term
firing rate of neuron that connects to eye muscle = tonic firing --> ? |
|
Definition
holds eye in that position |
|
|
Term
firing rate of neuron that connects to eye muscle = decrease/stopping in firing --> ? |
|
Definition
eye muscle contracting on the other/opposite side |
|
|
Term
how do you get eyes to move together? |
|
Definition
same neuron controls the lateral rectus of right eye & also the medial rectus of the left eye |
|
|
Term
does superior colliculus to ipsilateral or contralateral control? |
|
Definition
contralateral (just like motor cortex) |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
how do visual & motor neurons work together to get your eyes to reflexively saccade when something pops into your field of view? |
|
Definition
visual cells fire very quickly to tell you there is something there (LGN input)
short time after, motor cells fire to regulate saccade |
|
|
Term
if you drive current in a visual cell, what will happen to motor cells? |
|
Definition
it will drive EPSCs in the motor cell to drive an action potential to move eye to direct attention |
|
|
Term
how are visual & motor layers of SC connected? |
|
Definition
|
|
Term
experiment to determine that saccades are encoded in movement coordinates not retinotopic coordinates |
|
Definition
animal fixated on target, had another target appear, then have animal saccade to that target
HOWEVER stimulated SC to induce a saccade in a different direction |
|
|
Term
do oculomotor saccade neurons have tuning? |
|
Definition
yes (in either angular direction up/down or side/side neurons have preferred angles) |
|
|
Term
how is tuning organized for saccades? |
|
Definition
in response to place where you are wanting to move your eye to |
|
|
Term
pons vs midbrain saccade nuclei |
|
Definition
they exist to innervate neurons responsible for different movements:
pons = horizontal
midbrain = vertical |
|
|
Term
how is tuning determined for saccade neurons? |
|
Definition
neurons will show strong response to its preferred saccade but low response to saccades out of its range |
|
|
Term
area in the front of the brain that receives a lot of innervation from motor cortex & is responsible for saccades (**monkey brain**) |
|
Definition
|
|
Term
are there a lot or a few brain areas involved in visual-motor transformations? |
|
Definition
|
|
Term
are the sympathetic & parasympathetic systems the same or opponent? |
|
Definition
opponent (govern the functions of organ systems in a homeostatic manner) |
|
|
Term
is the autonomic nervous system (sympathetic & parasympathetic) under conscious control? |
|
Definition
|
|
Term
four F's autonomic nervous system (sympathetic & parasympathetic) are involved in |
|
Definition
1. fleeing 2. fighting 3. feeding 4. fucking |
|
|
Term
parasympathetic system roles |
|
Definition
|
|
Term
|
Definition
|
|
Term
are the same organ systems targeted by both parasympathetic & sympathetic systems or are they different? |
|
Definition
|
|
Term
why can the parasympathetic/sympathetic systems be thought of as reflexes? |
|
Definition
not under CNS conscious control! |
|
|
Term
do sympathetic & parasympathetic have the same or counteracting effects on target organs? |
|
Definition
|
|
Term
2 different layers of gastrointestinal tract targeted by visceral motor system |
|
Definition
1. Meissner's plexus: secretion of enzymes 2. myenteric plexus: regulates the muscles |
|
|
Term
what does Horner's Syndrome look like? |
|
Definition
|
|
Term
cause of Horner's Syndrome |
|
Definition
lesion of either the reticular formation or farther down spinal cord (unilateral!) that causes loss of sympathetic innervation |
|
|
Term
where is the hypothalamus located? |
|
Definition
|
|
Term
how is the hypothalamus organized? |
|
Definition
has different divisions that are in charge of different things |
|
|
Term
2 things hypothalamus is highly involved in |
|
Definition
1. visceral motor system regulation 2. regulation of hormones |
|
|
Term
2 sets of inputs to hypothalamus |
|
Definition
|
|
Term
4 outputs of hypothalamus |
|
Definition
1. visceral motor 2. somatic motor 3. neuroendocrine 4. behavioral responses |
|
|
Term
main role of hypothalamus |
|
Definition
compares input to biological set points |
|
|
Term
7 steps in HPA axis stress response |
|
Definition
1. stress signal 2. hypothalamus 3. CRH onto anterior pituitary 4. ACTH onto adrenal gland/kidney 5. cortisol release 6. metabolic effects 7. negative feedback loop to turn off stress |
|
|
Term
|
Definition
hypothalamus, pituitary, & adrenal |
|
|
Term
basically, sympathetic adrenergic response is involved in _______ |
|
Definition
|
|
Term
sympathetic responses work primarily through _______ |
|
Definition
|
|
Term
would lesioning different parts of the eye circuit get different phenological effects on eye movements? |
|
Definition
|
|
Term
how the shapes of neurons change as they grow |
|
Definition
neurons start round --> grow processes that become axon & dendrites |
|
|
Term
role of growth cone in neuron growth |
|
Definition
kind of seeks out neurons to synapse onto |
|
|
Term
growth cone has _______ on the end |
|
Definition
filipodia (look like little fingers) |
|
|
Term
a stain for actin on growing neurons will stain the _______ |
|
Definition
|
|
Term
a stain for microtubules on growing neurons will stain the _______ |
|
Definition
more structural, longer part of the cone |
|
|
Term
|
Definition
the sheet connecting the filipodia |
|
|
Term
how is calcium involved in neuron growth? |
|
Definition
involved in the growth of filipodia from the lamelliposdium |
|
|
Term
4 steps in initial neuron growing |
|
Definition
1. starts as a round shape 2. repulsion of efferent axon 3. attraction of apical dendrite 4. branching of dendrites |
|
|
Term
2 reasons why repulsion is important in neuron growth |
|
Definition
1. self-avoidance 2. get neurons to be nice & tiled between each other for circuit dynamics |
|
|
Term
role of chemoattractants in neuron growth |
|
Definition
can work to bring pioneer growth cones in a certain direction |
|
|
Term
2 things that can bring axons in a particular direction when neurons are growing |
|
Definition
1. chemoattractants 2. trophic factors |
|
|
Term
can a chemical be both a chemoattractant and a chemorepellent? |
|
Definition
yes! can vary within or across neurons! |
|
|
Term
how does an axon choose which side to go on at the optic chiasm when neurons are growing? |
|
Definition
the presence of a certain receptor on the axon will affect a neuron's attraction or repulsion to a chemical to influence its growth direction |
|
|
Term
why, if you rotate a frog's eye 180 degrees, will it flick its tongue down below when it sees a fly above it? |
|
Definition
the neurons innervating the bottom of the eye will still be attracted to muscles to move down to the bottom direction (even though topographically that part of the eye is on the top...anything seen with that part of the eye will be connected to muscles telling things to move to the bottom) |
|
|
Term
how is neuron growth from the retina maintaining its topography as neurons grow to the tectum? |
|
Definition
certain neurotrophic factors are present on the anterior or the posterior of the tectum to map retinotopy |
|
|
Term
early development neuron to muscle innervation pattern |
|
Definition
many neurons will synapse across many muscles |
|
|
Term
early on, do many or a few neurons innervate a given NMJ? |
|
Definition
|
|
Term
early on in development, will a climbing fiber wrap around many or a few Purkinje cells? |
|
Definition
|
|
Term
are neurotrophins equally attractive to all neurons? |
|
Definition
no (what will attract one neuron will probably not attract another neuron) |
|
|
Term
chemoattractants vs chemorepellents |
|
Definition
regardless of where a soma is, an axon will be drawn to its chemoattractants & away from its chemorepellents |
|
|
Term
are chemoattractants the same for all neurons? |
|
Definition
no (what is attractive to one neuron might be repelling to another) |
|
|
Term
|
Definition
|
|
Term
|
Definition
"cells that fire together wire together" |
|
|
Term
how is synaptic pruning done? |
|
Definition
certain inputs will receive neurotrophic factors & the ones that don't will die off |
|
|
Term
neuron organization: birth |
|
Definition
lots of neurites initially growing around |
|
|
Term
neuron organization: 2 years |
|
Definition
|
|
Term
neuron organization: 6 years |
|
Definition
synaptic pruning done, much more organized |
|
|
Term
firing in retina is tightly coordinated with ________ firing |
|
Definition
|
|
Term
what is the significance of the different innervation stripes in layer 4 of V1? |
|
Definition
information represented from the contralateral vs ipsilateral eye |
|
|
Term
cortical neuron responses to eye input: normal adult |
|
Definition
most neurons respond a little bit to both eyes; some strongly respond to one eye or the other |
|
|
Term
cortical neuron responses to eye input: monocular deprivation in kitten |
|
Definition
after only two days, you will see that eye no longer represented in the cortex |
|
|
Term
cortical neuron responses to eye input: monocular deprivation in adult |
|
Definition
after even dozens of days, you get less representation overall but you don't completely lose that eye in the cortex |
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Term
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Definition
a time in which plasticity can only occur in that time |
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Term
how does normal eye input look in L4 of V1? |
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Definition
good, strong arborization in L4 |
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Term
how does deprived eye input look in L4 of V1? |
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Definition
no firing --> lack of arborization --> looks dead |
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Term
what happens to tuning as an animal matures? |
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Definition
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