Neuroethology

Question 1

what are Tinbergen’s 4 questions about behavior?

Answer 1

what’s the function of behavior?
what’s its evolutionary history?
how is it developped?
how is it controlled?

Question 2

sensory system that aquatic animals use to navigate and locate/identify objects in the environment.

Answer 2

electrosensation

Question 3

sensory system used by animals to assist navigation by feeling the earth’s magnetic field

Answer 3

magnetoreception

Question 4

3 examples of sensory systems that we have but are not aware of

Answer 4

proprioception, vestibular system, pheromones processing

Question 5

system used to assess vibrational (mechanosensory - changes in pressure) signals in aquatic or semi-aquatic animals

Answer 5

lateral line system

Question 6

mechanoreceptive organ consisting of hair cells whose tips are covered by a flexible and jellylike cupula

Answer 6

neuromast

Question 7

antibiotic used to knock out lateral line system to be able to test it

Answer 7

gentamicin

Question 8

a way of encoding information about what’s in the environment that consists of different neurons/sensory cells that get activated by different types/range of stimuli

Answer 8

labeled-line coding

Question 9

a way of encoding information about what’s in the environment that consists of using pattern of activity across population of neurons to identify a stimulus

Answer 9

across-fiber coding

Question 10

2 examples of labeled-line coding

Answer 10

auditory transduction, light transduction (but not color perception)

Question 11

1 example of across-fiber coding

Answer 11

color perception

Question 12

5 steps of perception

Answer 12

signal, collection, transduction, processing, action

Question 13

what are the 2 mechanisms of transduction and what are they? what sense work by each mechanism?

Answer 13

mechanical: physical opening or closing of a channel; touch and hearing
second-messenger: G-protein coupled receptor triggers a biochemical cascade; taste, vision, olfaction

Question 14

motion between what structures causes mechanical transduction?

Answer 14

cytoskeleton and extracellular anchor

Question 15

what type of mechanoreceptors responds to light touch and low-frequency vibrations?

Answer 15

Meissner’s corpuscle

Question 16

what type of mechanoreceptor responds to deep touch and high-frequency vibrations?

Answer 16

Pacinian corpuscle

Question 17

what does the tension in tip links cause? (basically how sound is transduced)

Answer 17

opening of channels -> change in membrane potential -> transmitter release

Question 18

what is non-spiking transmission?

Answer 18

transmitter release varies continuously with hair-cell membrane potential

Question 19

what causes repolarization in hair cells?

Answer 19

opening of voltage-sensitive K+ channels - K+ exits hair cell into perilymph

Question 20

Why does the closing of K+ channels in the stereocilia lead to hyperpolarization of the hair cell?

Answer 20

permanently open K+ channels at the base of the hair cell (K+ exits the cell)

Question 21

how does olfactory transduction work?

Answer 21

binding of odorant to olfactory receptors activates second messenger (G-protein) cascade, cAMP is formed and opens ion channels, leading to depolarization and AP

Question 22

what happens in photoreceptors in the dark?

Answer 22

there is a high level of cGMP that causes a high resting Na+ conductance (Na+ channels are open)

Question 23

What is FAD and how does it work?

Answer 23

light sensitive chromophore: FAD converts to magnetically sensitive FADH free electron/radical when photoexcited

Question 24

what type of hair cells is the most important for transduction?

Answer 24

inner hair cells

Question 25

what kind of movement in the basilar membrane trigger depolarization of hair cells?

Answer 25

upward movement

Question 26

which part of the basilar membrane is more rigid and what frequencies does it respond to?

Answer 26

base; responds to high frequencies

Question 27

what does amikacin do?

Answer 27

blocks basilar membrane response to high frequency sounds

Question 28

what are the 2 ways how sound amplitude is transduced?

Answer 28

number of activated neurons; AP firing rate per neuron

Question 29

what do IID and ITD stand for? how can you test each?

Answer 29

interaural intensity difference, block an ear; interaural timing difference, move speaker left to right or play specific ITDs in earphones

Question 30

what was the results of the experiment of blocking one of barn owl's ear?

Answer 30

they did errors in locating the elevation

Question 31

describe the 2 pathways (one for ITD, one for IID) from inner hear to ICx (external nucleus of inferior colliculus)

Answer 31

ITD: inner hear -> nucleus magnocellularis -> nucleus laminaris -> anterior lateral lemniscus -> central nucleus of auditory midbrain (inferior colliculus) -> ICx IID: inner hear -> nucleus angularis -> posterior lateral lemniscus -> central nucleus of auditory midbrain (inferior colliculus) -> ICx

Question 32

where does information between right and left hear cross?

Answer 32

between nucleus magnocellularis and nucleus laminaris - NL is where information converges

Question 33

what does inactivating NM neurons do? what can we conclude from that?

Answer 33

it affects ITD response of ICx neurons, but not IID, therefore NM neurons responds to change in azhimut

Question 34

what does inactivating NA neurons does?

Answer 34

it affects IID response of ICx neurons

Question 35

what are coincidence receptors? give an example

Answer 35

neurons in nucleus laminaris detect the coincidence of input (Jeffress model)

Question 36

explain de depolarization window in nucleus leminaris

Answer 36

coincidence detection neurons as being maximally excited by particular ITDs, but partially activated for similar ITDs

Question 37

what characteristics of sound do crickets and frogs listen to to identify their friends?

Answer 37

differences in rate (frequency) and number of pulses

Question 38

HVC neurons in birds are sensitive to what?(allows them to recognize their friends)

Answer 38

specific sound sequences

Question 39

definition of temporal integration? and name 3 examples

Answer 39

neural responses to particular stimuli depend on the timing of stimuli; ITD, rate and nb of pulses (crickets and frogs), sequence dependent activation (zebra finches)

Question 40

what neurons fire to specific pulse rates in crickets? what about in frogs?

Answer 40

AN1 neurons for crickets; inferior colliculus neurons for frogs

Question 41

what is the equivalent of superior colliculus in vertebrates?

Answer 41

optic tectum

Question 42

where are the neurons that mediate pursuit behavior of prey (are stimulated by worm-like stimulus)? what is this type of neurons called

Answer 42

in optic tectum; feature detectors

Question 43

what is the definition of feature detectors?

Answer 43

neurons that code for perceptually significant stimuli.

Question 44

what happens to toads when you cut the link between thalamic pretectum and optic tectum

Answer 44

toads loose selectivity to worm-like stimuli and actually respond more to non-worm-like stimuli

Question 45

which one is the most precise selection between orientation and direction selectivity?

Answer 45

direction selectivity

Question 46

explain the 2 pathways from retina to extrastriate visual cortex

Answer 46

1. retina -> thalamic lateral geniculate -> primary visual cortex -> extrastriate visual cortex 2. retina -> superior colliculus -> extrastriate visual cortex

Question 47

what is the function of multimodal integration?

Answer 47

Using information from multiple sensory systems (e.g., vision and auditory) to help in the detection and localization of objects, especially with signal intensity is LOW in each modality