MT1 Sample Flashcards
The action potential and synaptic potential are actually special cases of the membrane potential
True
Name 3 properties of ion channels
ion selectivity, kinetics (time they stay open, etc) state (active, deactivated, etc.)
The neurotransmitter GABA: A. is inhibitory B. opens Cl- channels C. is excitatory D. is a neuromodulator E. depolarizes post-synaptic targets F. A and B G. C and E
a. inhibitory b. allows Cl- ions into cell, K+ out of cell
What kind of activity is measured at the level of a nucleus? A. fMRI B. EMG C. graded potential D. action potential E. none of the above
none of the above (EEG)
Name the 5 properties of ion channels
ion selectivity (what does it let in?) gating mechanism (how does it open?) kinetics (how long does it open) state (is it available to be opened?) location (where is it?)
Dopamine is a neurotransmitter that is directly excitatory
False Dopamine is a neuromodulating neurotransmitter
Membrane potential is a special case of equilibrium potential
False Equilibrium potential is a special case of membrane potential
During action potential, _____ rushes into the cell, followed by ____ rushing out
Na+ rushes in, then K+ rushes out
If Neuron A fires an action potential after simultaneously receiving an EPSP from Dendrite 1 and Dendrite 4, it is an example of: a. IPSP b. temporal summation c. spatial summation d. local summation e. none
c. spatial summation
Dorsal root ganglian cell is located in the spinal cord
False. The dorsal root ganglian is a cluster of nerve cell bodies (a ganglion) in the posterior root of a spinal nerve. Their axons are afferents that relay sensory information into the central nervous system. The differ from majority of neurons in that an action potential in a posterior neuron may initiate in the distal axon, bypass the cell body, and continue to propagate along the proximal axon until reaching the synaptic terminal. Bare nerve ending in the distal end, possibly covered by meissner or pacinian corpuscle.
What are the characteristics of a pacinian corpuscle? shallow/deep ? small/large receptive field? high/low frequency? transient/sustained?
A pacinian corpuscle (onion skin) is: deep large receptive field high frequency transient //sensitive to vibration and pressure //respond to sudden disturbances // ~250 Hz
//unmylenated end of DRG is wrapped by skin cells like an onion
What are the characteristics of a Meissner’s corpuscle?
shallow small receptive field low frequency transient //~10-50 Hz // gripping objects //epidermis with unmylinated end of DRG wrapped around it
There is a higher density of Merkel disks on your finger than your arm
true
What are the characteristics of Merkel disk cells?
shallow placement
small, spotty field
sustained
two point discrimination
//sensitive to form, edges, texture
What two types of mechanoreceptors are probably involved in reading Braille?
merkel disks
meissner’s corpuscles
Where do we FIRST start to get direction selectivity from a single cell?
a. S2
b. S1
c. VPN
d. spinal cord
e. none of the above
S1
S1 is located in the precentral gyrus
false
S1 is located in the (parietal lobe-somatosensory cortex) postcentral gyrus.
It is the main sensory receptive area for TOUCH
Signals from mechanoreceptors in your left hand end up in your right brain hemisphere
true!
signals from mechanoreceptors in your right hand cross over to the left brain hemisphere too
Weigert stain stains for
a. soma
b. axons
c. whole neurons
d. whole glia
e. none of the above
Weigert stain stains for AXONS
Generator potentials are analogous to [synaptic] / [action] potentials
‘Microslip’ events are best detected by the _______ of touch receptor.
meissner’s corpuscle
Recordings of neurons along [oblique] / [vertical] trajectories through visual cortex yield neurons with different directional tuning preferences.
Which type of bipolar neuron is depolarized by the neurotransmitter glutamate?
Ganglion cells of which type have responses to light that are analogous to Pacinian corpuscle responses to touch?
Ocular dominance columns in the left V1 alternate between inputs from the left and right eyes (t/f)
TRUE
The pinwheel map contains information for color. (t/f)
FALSE; pinwheel map refers to orientation of stimulus (e.g. orientation of bar)
MST neurons show selectivity for what type of stimuli?
(medial superior temporal region)
moving stimuli in a certain direction
The action potential and synaptic potential are actually special cases of the membrane potential.
true
On an otherwise dark field of view, light in the form of a plus sign in the upper-left field of view will excite neurons in the
RIGHT LOWER V1
Ganglion cells of which type have responses to light that are analogous to Pacinian corpuscle responses to touch?
pacinian corpuscles have a TRANSIENT response… just as MAGNOCELLULAR ganglion cells in the visual system
Which type of bipolar neuron is depolarized by the neurotransmimer glutamate?
OFF bipolar cell
(circle the appropriate word) Recordings of neurons along [oblique] / [vertical] trajectories through visual cortex yield neurons with different directional tuning preferences.
OBLIQUE
neurons in a single cortical column (vertical) have the SAME directional tuning preferences
‘Microslip’ events are best detected by the _______ of touch receptor
meissner corpuscle
Generator potentials are analogous to [synaptic] / [action] potentials.
SYNAPTIC
The ‘Pinocchio Effect’ involves a resolutioon of contradictory information supplied by which two sensory systems of the brain?
proprioceptive
somatosensory
Which area of parietal cortex is known to integrate both tactile sensation and visual information?
area VIP (ventral intraparietal)
[monkey experiment with fixed gaze, touching monkey, then presenting visual stimuli in same field; same firing pattern in single cell recording; integration of somatosensory and visual “personal space”
As visual information moves from V1 to later processing stages along the ‘what’ pathway, the features being processed become increasingly specific. (T/F)
FALSE
as you move from V1 you get increasing generalization across stimulus features (increasingly abstract) due to convergence of different types of information. start to lose retinotopy, receptive field sizes increase, start to respond to shapes, etc.
Ocular dominance columns were found by staining for what enzyme?
cytochrome oxidase. it is needed to produce ATP
Where does integration first occur between the proprioceptive and somatosensory systems?
S1 (think pinnochio effect)
There are more neurons in V1 dedicated to the ______ of gaze. This phenomenon is called ______ expansion.
(center) ; foveal expansion
In which layer of the visual cortex is sustained and transient information first integrated?
layer 4
Magnocellular information comes into layer ______, and magnocellular neurons are _______adapting
layer 4;
magnocellular is transient; rapidly adapting
Left LGN has information coming from which eye?
BOTH eyes