The Central Visual System

Question 1

What are the types of retinal receptive fields?

Answer 1

ON-center/OFF-surround
OFF-center/ON-surround

Question 2

Hypothalamus role

Answer 2

biological rhythms, including sleep and wakefulness

Question 3

pretectum role

Answer 3

control size of pupil, certain types of eye movement

Question 4

superior colliculus role

Answer 4

orients the eyes in response to new stimuli - move fovea to objects of interest

Question 5

what are nonthalamic targets of the optic tract?

Answer 5

hypothalamus, pretectum, superior colliculus

Question 6

which layers of the lgn are contralateral

Answer 6

1,4,6

Question 7

primary visual cortex provides 80% of the synaptic input to _______

Answer 7

the Lateralal geniculate nucleus

Question 8

receptive fields of LGN neurons

Answer 8

almost identical to the ganglion cells that feed them

Question 9

magnocellular LGN neurons

Answer 9

large center-surround receptive fields with transient response

Question 10

properties of parvocellular LGN cells

Answer 10

small center-surround receptive fields with sustained response

Question 11

which area of the brain contains the striate cortex

Answer 11

area 17

Question 12

enlarged _______ leads to gigantism and tunnel vision

Answer 12

pituitary gland

Question 13

what vision would be lost from lesion of the left optic nerve

Answer 13

left peripheral vision

Question 14

what vision would be lost from lesion of the left optic tract

Answer 14

all right-side vision

Question 15

what vision would be lost from lesion of the optic chiasm

Answer 15

all peripheral vision

Question 16

brain stem neurons provide

Answer 16

modulatory influence on neuronal activity

Question 17

where do the koniocellcular layers (K1-K6) lie

Answer 17

ventral to the principal layers of the same number

Question 18

Are parvo or magno cells bigger

Answer 18

magno

Question 19

“top-down” modulation may gate _______ input from LGN back to cortex

Answer 19

“bottom-up”

Question 20

how are the inputs in the LGN segregated

Answer 20

by eye and ganglion cell type

Question 21

what is another name for the primary visual cortex

Answer 21

striate cortex

Question 22

what part of the optic tract does the pituitary sit adjacent to?

Answer 22

the optic chiasm

Question 23

In a retinotopic map, the _____ is overrepresented

Answer 23

central visual field (fovea)

Question 24

RM - many cells in the target structure can be activated by

Answer 24

a discrete point of light due to overlapping receptive fields

Question 25

how many layers are in the striate cortex

Answer 25

6

Question 26

spiny stellate cells in V1

Answer 26

have spine covered dendrites. found in layer 4C

Question 27

pyramidal cells in V1

Answer 27

have thick apical dendrites with spines. found in layers 3, 4B, 5, 6

Question 28

inhibitory neurons in V1

Answer 28

no spines. form local connections in all cortical layers

Question 29

magnocellular LGN neurons project primarily to which layer of the striate cortex

Answer 29

layer 4C alpha

Question 30

parvocellcular LGN neurons project to

Answer 30

layer 4C beta of the striate cortex

Question 31

koniocellular LGN axons make synapses primarily in

Answer 31

layers 1 and 3 of the striate cortex

Question 32

Which cortical layers project to other cortical areas?

Answer 32

2, 3, and 4B

Question 33

What cortical layer cells project to the superior colliculus and pons?

Answer 33

layer 5

Question 34

What cortical layer cells project back to the LGN?

Answer 34

6

Question 35

studied with transneuronal autoradiography, ________ shows alternating inputs from two eyes

Answer 35

ocular dominance columns

Question 36

first binocular neurons found in

Answer 36

striate cortex

Question 37

the striate cortex binocular neurons start at which layer

Answer 37

layer 3

Question 38

developmental plasticity in ocular dominance occurs at the level of

Answer 38

the cortex

Question 39

cytochrome oxidase

Answer 39

mitochondrial enzyme used for cell metabolism

Question 40

what are blobs

Answer 40

CO-stained pillars in the striate cortex representing ocular dominance

Question 41

orientation selectivity

Answer 41

a bar of light's orientation can determine the degree of reaction from the cell

Question 42

direction selectivity

Answer 42

neuron fires AP in the direction-dependent response to moving bar of light

Question 42

properties of complex cell receptive fields

Answer 42

binocular, orientation-selective, ON and OFF responses to the bar of light WITHOUT distinct regions

Question 42

properties of simple cell receptive field

Answer 42

binocular, orientation-selective, elongated ON or OFF area flanked with antagonistic surround

Question 42

properties of cortical module columns

Answer 42

4c concentric fields, 30-150 microMs wide and 2 mm deep

Question 43

calcium imaging uses

Answer 43

voltage sensitive dyes embedded in membrane

Question 43

cortical modules are capable of

Answer 43

analyzing every aspect of a portion of the visual field