Final

Question 1

Systems neuroscience

Answer 1

circuits of neurons that interact to perform some function

Question 2

Neural Coding

Answer 2

How information is represented in neural activity

Question 3

Action Potential Frequency

Answer 3

External information is represented by the number of action potentials that a neuron admits in a certain time window
Higher firing rate = stronger sensory singal

Question 4

Coordinated Activity

Answer 4

Precision of spikes among different neurons (more precision = stronger signal)

Question 5

Graded Potential

Answer 5

Amplitude of depolarization codes for the strength of a sensory signal (Greater amplitude = greater strength)

Question 5

Central Pathway

Answer 5

Sensory signal transmitted from peripheral neurons to central neurons in the brain

Question 6

Sensory Receptors

Answer 6

Convert external sensory information into neural activity so that other neurons can recognize it.
Cells that transduce energy to electrical activity to be passed on to other neurons; Can be specialized to detect different features of the same input

Question 7

Receptive field

Answer 7

location in the environment of surface of body from which the appropriate stimulus will change the cell’s activity

Question 8

Topographic Map

Answer 8

Orderly representation of the sensory space in the nervous system

Question 9

Phototransduction

Answer 9

Conversion of light energy into neural activity

Question 10

Pupil

Answer 10

Opening that allows light to enter the eye

Question 11

Iris

Answer 11

Colored part of the eye: Controls amount of light reaching the eye by changing the size of the pupil

Question 12

Cornea

Answer 12

Covers pupil and iris, involved in refraction of light

Question 13

Sclera

Answer 13

White part of the eye

Question 14

Extraocular Muscles

Answer 14

Control eye movement

Question 15

Fovea

Answer 15

Center of vision, where light can directly reach photoreceptors, provides color and high resolution vision

Question 16

5 Major Types of cells in the retina

Answer 16

1. Retinal Ganglion cells
2. Amacrine cells
3. bipolar
4. Horizontal cells
5. Photoreceptor cells

Question 17

Photoreceptors

Answer 17

Only cell type directly affected by light

Question 18

Retinal ganglion cells

Answer 18

only cells that generate action potentials in the retina

Question 19

Linear (Direct) pathways

Answer 19

• Photoreceptors -> Bipolar cells -> Retinal ganglion cells
• Parallel to the path of light

Question 20

Lateral (indirect) Pathway

Answer 20

-Photoreceptors -> Horizontal cells -> bipolar cells -> amacrine cells -> RGC
- Perpendicular to the path of light

Question 21

Rods

Answer 21

Sensitive to light, low acuity vision, achromatic, rare in fovea

Question 22

Cones

Answer 22

High acuity vision, low sensitivity to light, color sensitive, concentrated in fovea

Question 23

Photoreceptors in the dark

Answer 23

-cGMP binds to cGMP gated Na+ Channel
-cGMP keeps channel open, allows Na+ influx
- Photoreceptor cell membrane remains depolarized (-30 mV)
- Glutamate constantly released at terminal

Question 24

Photoreceptors in the light

Answer 24

- Light stimulation reduces cGMP - Na+ channel closes, membrane hyperpolarizes (-65mV) - Glutamate release stopped

Question 25

Rhodopsin

Answer 25

light-sensitive protein, where transduction takes place

Question 26

1st step of light decreasing cGMP

Answer 26

light hits rhodospin

Question 27

2nd step of light decreasing cGMP

Answer 27

Conformation of rhodopsin changes, activates transduction (G-protein)

Question 28

3rd step of light decreasing cGMP

Answer 28

transducin activates phosphodiesterase catalyzes hydrolysis of cGMP to GMP

Question 29

4th step of light decreasing cGMP

Answer 29

Na+ channels close, cell hyperpolarizes (degree depends on light intensity)

Question 30

Action potential by a neuron in a pain system

Answer 30

perception of pain

Question 31

Action potential by a neuron in the visual system

Answer 31

perception of sight

Question 32

action potential by a neuron in a motor system

Answer 32

movement

Question 33

Action potential by a neuron in a system underlying emotion

Answer 33

feeling of fear or another emotion

Question 34

Subsystems

Answer 34

neurons in different subsystem code for different functions.

Question 35

How images are projected onto the retina

Answer 35

image is inverted, different receptive fields correspond to different parts of the image

Question 36

Photoreceptor receptive field

Answer 36

-circular -determined by location in the retina -responds to changes in light intensity

Question 37

Periphery receptive field

Answer 37

consists of all photoreceptors in one area, has a bigger receptive field, consists of Magno-type ganglion cells

Question 38

Fovea receptive field

Answer 38

consists of few photoreceptors, has a smaller receptive field allowing for higher resolution vision, consists of parvo- type ganglion cells

Question 39

Receptive field overlap

Answer 39

Divergence of signals from one photoreceptor cell onto multiple neighboring retinal ganglion cells

Question 40

RGC Receptive field

Answer 40

Center sorround

Question 41

On center ganglion cells

Answer 41

light increase in center = AP firing increase Light increase in surround = AP firing decrease

Question 42

Off center ganglion cells

Answer 42

light increase in center = AP firing decrease Light increase in surround = AP firing increase

Question 43

On Center bipolar cell

Answer 43

- contains inhibitory glutamate receptors - Hyperpolarized in darkness, depolarized in light

Question 44

Off center bipolar cell

Answer 44

- Contains excitatory glutamate receptors - depolarized in darkness, hyperpolarized in light