Neuro exam 2

Karl Von Frisch: Ethologist,most famous for:

-studying the dance language of bees -if you have a scout go out & discover rich food source, need to communicate this to hive, different ways to do so.

what is an important cue to bees and why?

gravity, bc allows them to orient themselves -can detect direction of pole of gravity (their mechanoreceptors are differentially stimulates to tell them what is up or down)

Adult sea turtles:

have innate ability to determine direction, but also have learned/preferred feeding areas where they are sheltered & have a lot of food.

What is a great potential cue for sea turtle who has just entered surf & wants to get away from beach?

when waves come in, there is wave diffraction caused by changing depth in water (getting close to shallow water)

Bees also have great circadian rhythm which:

will compensate for the movement of the sun. -so if waggling over the course of an hour, will adjust their angle, to compensate how the sun moved relative to the food source

intensity cues processed in

NA

timing cues are processes in

NM

Visual systems:

animals only perceive what is useful. -so visual system emphasizes some info & throws rest away

The optic tectum of owls in homologous to (same structure as): a) inferior colliculus of mammals b)superior colliculus of mammals c)superior olive of mammals d)neocortex of mammals e)none of the above

b) superior colliculus of mammals (& humans)

Which cues, AND in what order in time, do hatchling loggerhead sea turtles use to orient as they navigate to the gyre. a) visual cues, then wave sounds, then magnetic cues b) visual cues, then wave direction cues, then magnetic cues c)magnetic cues, then wave direction cues, then visual cues d)visual cues, then magnetic cues, then wave direction cues e)none of the above

b) visual cues, then wave direction cues, then magnetic cues

Sound intensity cues in the barn owl are first sent to which brainstem nucleus, or nuclei: a)Nucleus collicularis b)nucleus angularis c)the habenular nucleus d)nucleus magnocellularis d) a & c e) a & b

b)nucleus angularis (know this bc: NM-ITD-Azimuth [MTA] NA-IID-Elevation [AIE] SO: sound intensity=nucleus angularis, IID)

Picture shown: (In center) left(--dots--speaker----)right A juvenile owl was involved in experiment examining brain plasticity. The data shown above are orienting responses to sounds in total darkness. Based on your understanding of Knudsen's work, which of the following are possible conditions for the owl when these data were collected? a)the owl had just been fitted with 23 degree left shifting goggles b)the owl has been wearing 23 degree left shifting goggles for many weeks c)the owl just had 23 degree right shifting goggles removed after many weeks d) the owl just had a left earplug removed after many weeks e)the owl just had a right earplug removed after many week f)a&b g)b&c h)c&e f)none

b)the owl has been wearing 23 degree left shifting goggles for many weeks (shows shift in visual responses for azimuth, if it was right shifting goggles, the visual part, or dots, would be far to the right, showing direction of head to the right, even though object/speaker to left. left shifting goggles shows speaker in center, and head shifted far to the left, object/speaker to the right. & know it's not d/e bc earplugs tests for elevation/up & down, not azimuth/horizontal like this test)

Knudsen is known for his research on:

barn owls

magnocellular nucleus (NM) is _____________ while Angular nucleus (NA) _______

NM=phase locked NA=responds to intensity differences

what is the waggle dance?

-directional communication -uses direction of gravity as proxy for direction of sun -movement of bee from gravity responds to angle b/w sun & food -allows other bees to determine where food is -means wherever sun is, want to go x degrees of the sun to search for the food.

Ants:

go to food source, then back to nest -clip legs=makes more steps stilts=makes fewer -they do count steps -clipped legs look for nest closer -more fixed than bees

Heroic acts in colonies that explain why jarvis never found the queen:

-1/3 of their muscles in their jaws -use front teeth to dig tunnels -can do considerable damage to prey:snake -defends the queen

Brain parts (mammals)

-cerebral cortex(visual cortex) -thalamus(lateral geniculate nucleus) -midbrain (pretectum & superior colliculus) -cerebellum/pons (cell groups that control eye movements) -medulla & spinal cord

what is the honeybess round dance?

-circular dance where they go back & forth in a circle -"hey, big food source out there within 50m of hive, fly out & find it" -the nectar smell on their body from food source serves as a cue & a clue as to where to find the food

closer to ground= ____ optic flow -further from ground- _____ optic flow

-closer to ground=more optic flow -further/higher from ground=less optic flow, & thinks it flew a shorter distance

how do bees make smooth landings?

-keep optic flow constant as they land -as you get closer, things go faster, so you slow down. -as optic flow increases, your speed reduces=grazed landing

Male morphism: a dispersive morph in the naked mole rat:

-promotes outbreeding in naked mole rats -make form that is a disperser that tries to leave the colony -laden with fat, exhibit elevated levels or luteinizing hormone, have a strong urge to disperse, & only solicit mating with non-colony members

Horizontal component (timing difference/azimuth) & intensity (difference between 2 ears)

-put electrode in ICS -licodaine=sodium channel blocker-injected to deactivate (reversively) one or 2 of those nuclei -in NM affected timing, not intensity -in NA affected intensity responses, not timing

Honeybees:

-recruit other bees to food sources -in spring time have big advantage bc they have ability to collect pollen (40k bees in 1 colony) -larger reproductive tract (lays as many as 2000 eggs a day)

most of visual processing is done without conscious awareness such as:

-saccadic eye movements -changes in pupil size -changes in lens shape

Characteristic of Alexander's mythical Eusocial vertebrae (mostly based on termites):

-safe, expandable nest, near abundance of food obtainable with little risk -completely subterranean rodent -feeds on large,underground roots & tubers -lives in wet-dry tropics -in soil of hard clay -major predator would be able to enter burrow but be deterred by "heroic" acts of one or a few individuals -lifespan of 20 yrs -reproductive females may have 20 or more young -1 queen, few drones, helpers that do all the work & forage for food -colony structure (useful)

Difference between instint/innate vs learning: Lohmann studies

-set of currents is critical for animals to stay within while juvenile. bc northern current is too strong for them to fight, its too cold & theyll freeze to death. he took hatchling sea turtles and put them in lab arenas, subjected them to magnetic fields characteristic of different locations in atlantic & looked at the direction they swam. =innate *newborn turtles have innate ability to try to swim in directions that are appropriate

How do compasses need to be adjusted for different regions of the earth--& why (be specific)?

-the magnetic field lines that run from the magnetic south pole (geographic north pile) are subtended directly depending on where you are on the earth (so magnetic north is actually geographically south & vice versa) -a compass must be calibrated to follow the subtended angle of the magnetic field that goes to the right magnetic pole. -there are variations in direction of magnetic field lines in different locations of the earth.

honeybee challenge?

-trying to get resources to survive throughout another winter -if sting a person, can lose their sting (spines stick in skin & will continue pumping venom) -bees die when lose their stinger

Eusociality

1 queen producing all the young -caste of workers performing different tasks

properties of visual wulst are similiar to primary visual cortex of mammals

1) Retinotopy 2) Binocular and monocular segments 3) Ocular dominance segregation 4) Disparity detectors 5) Orientation units

3 things to do: sea turtles

1) avoid silhouettes 2)head towards bright area 3)swim into waves

maximum time delay to travel across nucleus

160 ms -as you vary difference between speakers, its about 160 ms, directly right or directly left (most delay you have) -no delay between 2 ears, just delay between speaker & head

In 1970, a biologist named_____ was giving a lecture in Michigan and described the biology of a theoretical Eusocial mammal that resembled a mole-rat.

Alexander

Nucleus Laminaris researched by: & how?

Carr & Konishi -barn owls -showed presence of NL -NL has delay lines & coincidence detectors -delay lines are only part of inputs within actual nucleus -neurons enter opposite sides of nucleus -good layout of cells in NL

What are two important components of the Jeffress model for creating a map of auditory space?

Delay lines (axons) & coincidence detectors (neurons)

T or F: Neurons projecting from the barn owl's nucleus mangocellularis branch to supply information to both nucleus angularis and nucleus laminaris.

False (NM only branches to supply info to NL)

T or F: After young owls were trained to goggles that shifted vision 23 degrees to the right, they could later adapt (as adults) to goggles that shifted vision 23 degrees to the left.

False

T or F: The first map of auditory space was identified in the owl's ICC.

False (first map of auditory space was identified in the owls ICX).

T or F: Bumblebees over-winter with a small number of workers in the colony.

False, (in notes: over winter, 1 queen & few works. in beginning bees not fed very well bc so many, and over summer, workers get larger & larger and fed more. over winter with a huge colony of 40k workers in a nest, so have a huge advantage in spring for collecting pollen)

Libersat:Jewel wasp needs to develop within cockroach, which is challenging. whats the process?

First stings it in the thoracic ganglion between front legs that control them, then in the head/brain so it can control it when has to lead it a long distance to the hole, then clips antennae off, & uses it as a straw to drink roach blood so can get protein useful for making its egg, now laying egg on second leg of cockroach bc hard for it to reach/clean & groom there, & then going to brick the cockroach in & leave it in the tunnel and doesn't let it escape. Egg hatches and consumes the cockroach.

Number the following tasks 1-4 (1=youngest bee, 4=oldest bee) to indicate the relative age at which bees perform each task: Guarding___ Foraging___ Cleaning___ Storing Pollen___

Guarding=3 Foraging=4 cleaning=1 storing pollen=2 (so when first born 1)clean, bc safe/don't leave hive. [2)brood tending which isn't included] so 2)storing pollen & nectar 3) guarding 4)foraging [4)becoming foragers (guard) toward end of lives/oldest bees in colony. bees will sacrifice themselves when sting people, stinger imbedded in skin & detach when it stings,& stinger continues to inject venom even after, and bee will die after)

Bird vision researchers:

Harvey Karten & Jack Pettigrew

optical imagining detects reflectance changes based on:

relative brain activity

(picture) above are behavioral date from 2 different honeybee hives showing how scout waggle duration relates to distance flown. One hive is located in dense forest, the other is located in the open plain. Which hive is most likely in dense forest? pic shows waggle duration vs distance flown for the two hives. Hive A is above and longer so longer waggle duration, but both Hive A and hive B have same distance. Hive B is below but doesnt go as high showing shorter waggle duration.

Hive A. because dense forest=greater optic flow, so longer waggle dance

researcher who studied naked mole rats and could never find a reproducing female:" what's the deal with these weird mole-rats? seems like there's only 1 breeder per colony..."

Jarvis

Jeffress model for creating a map of auditory space: explain:

Jeffress proposed that by a system of delay lines and coincidence detectors, we could create a map of auditory space. If a sound stimulus is presented to one side, then that same side will travel along delay lines until it reaches the input from the other side at some coincidence detector.

Who studied sea turtles?

Ken Lohmann

______ studied sea turtle navigation in loggerhead turtles

Ken Lohmann

who studies jewel wasp

Libersat

_____ researcher: saw bees doing waggle dances on the swarm of bees, (germany after ww2, so not many resources/observations, but was able to follow bees back to nest, noticed signaling & one bee goes to only 1 location)

Lindauer

Jeffress model for creating a map of auditory space diagram & outline

O / \ / \ / \ / \ / \ Left ear O-o-o-o-o-o-O Right ear A B C D E This one is showing when sound encounters each ear simultaneously, an action potential is generated in each afferent (A-E). Each AP generates a response in each neuron as it travels down the pathway, but at neuron C, these action potentials hit the cell at the same time. This is the coincidence detector (where you get the maximal post-synaptic response).

_______studied optic flow in honeybee navigation

Srinivasin

What does the sea turtle use their back foot for? & Each one that they use tells you what? (like what is the sea turtle trying to do?

Their back foot helps turn. If stick our right back foot, going to turn right, if stick our left back foot. going to turn left.

Bee decision making: researcher:

Tom Seeley: (did hive experiment on island) -bee decision making -leave hive, form big cluster of hanging bees -must decide hive location

The visual system emphasizes ____ & _____ contrast, not ________ ______.

The visual system emphasizes spatial and temporal contrast not overall luminance.

The visual systems of birds & mammals:

The visual systems of birds and mammals although specialized in different ways share a number of conserved features.

(Picture) Better the bee has gotten stuck in traffic on the way back to the hive. She has chosen to fly down the center of the road. Which truck is she most likely to run into? Truck A, which is going past her, or truck B, that is going in same direction as her.

Truck B. bc truck a=faster, move away from faster moving object. truck b=slower

T or F: After months of training with goggles that shift the visual world by 6 degrees at a time, an adult barn owl can orient to the same position for both auditory and visual cues.

True

T or F: Auditory afferents (inputs) terminating/synapsing on neurons in the magnocellular nucleus often have giant terminals that surround the post-synaptic cell body.

True

T or F: Myelin segments in nucleus laminaris are shorter than segments outside of nucleus laminarius (making nodes of Ranvier closer together).

True

T or F: Bees cannot focus their eyes to different depths/distances.

True (bees have eyes very close together, don't focus or move their eyes, so depth perception is very great)

____ worked with Jarvis, and stood up at the end of Alexander's lecture on hypothetical eusocial mammal and told him that he just described the naked mole rat

Vaughn

Bees make smooth, soft landings by: a)adjusting their air speed to keep optic flow constant during decent b)adjusting their air speed to increase optic flow during decent c)adjusting their air speed to decrease optic flow during decent. d)none of the above

a) adjusting their air speed to keep optic flow constant during decent (if bees are made to fly through narrow place, they decrease speed. As narrows, optic flow increases, so slow down to decrease optic flow. Bees are good at making smooth landings. As descend,keep optic flow constant. Further the distance, the less accurate, but use landmarks to help lessen that error).

Picture showing a sea turtle with its left foot out, and right foot back: The hatchling sea turtle above has entered the surf. When a wave passed, it first experienced: acceleration ________(upward vs. downward) followed by acceleration _____(right, backward, left, forward).

acceleration upward followed by acceleration right. (since it's turning left, the wave is coming from that way, so it will go up, then right.and since wave just passed, know will accelerate upward. if wave is coming at you, would probably accelerate downward, to not get caught in and pushed back by wave.)

vision is an ____ process

active

How did roger payne prove eye structures are not IR detectors

brought animals into dark area & observed accurate striking -carbon paper to listen & mark where owls talons hit -stimulus that guides owl to mouse -tie a noisy piece of paper to mouse, & put mouse on silent surface -owl strikes paper, so not IR, not smell, they go after noise

The image below shows recordings of an environmental sound from microphones in the right & left ears of an owl. Circle the letter around the owl that indicated the likely point of origin for the sound. Sound intensity: /\ __/ \/\/\___ right ear /\ / \ /\ _____/ \/\/ \__ left ear A B C D owl E F D H

circle F, because, we see hits right ear first so right side but left ear is more intense, so below right up, left down

dance language:

communication going on between scouts who go out to get food & their scout mates, (happens in the dark)

Lateral geniculate nucleus (thalamus)=

conscious vision

The visual system of vertebrates contain groups of brain cells that perform specialized functions such as:

control pupil size, lens shape, inform the animal about where and what an object is and whether it is day or night.

Phase ambiguity is resolved by: a)integrating IID information in the optic tectum b) saccasic head movements that provide visual feedback to the ICX. c) phase locking to the second harmonic of each frequency d)convergence of ITD information for multiple frequencies in the ICX. e)feedback connections from the lower level of the optic tectum f)none of the above

d) convergence of ITD information for multiple frequencies in the ICX. (solution if for the nervous system to combine & integrate information from different frequencies to eliminate phase ambiguity. This integration of info to form the unambiguous map of location does not occur until information converges in the ICX.)

After juvenile barn owls had adjusted auditory responses to compensate for 23 degree vision shifting goggles, Knudesen found that: a) auditory responses had shifted in the ICC. b)new connections had sprouted between the ICX & the optic tectum. c)receptive fields had shifted in nucleus laminaris. d)new connections were formed between the ICC & the ICX. e) none of the above

d) new connections were formed between the ICC & the ICX.

Honeybees exhibit swarming behaviors in order to: a)collect pollen & nectar in the fall, before the long winter. b)collect pollen & nectar in the spring, when they have a competitive advantage over other species of bees c)to defend the nest from predators d)create a new hive by following a queen e)none of the above

d) to create a new hive by following a queen (When bee colony gets to a certain size, will have a new queen, this is called swarming. Obsessed with following the queen. Hang from tree=giant ball of bee, and send scouts to try to find a new nest site)

Mole-rats have a queen caste, worker caste, a soldier caste, & ____:(name one more caste described in class)

disperser morph

if you remove the feathers you:

disrupt auditory localization

NA:

doesnt have wrapping around the cell that is required for specificity

Which of the following is NOT true of barn owls: a)they have prominent, non-stick pads on their feet. b)their eyes do not move independent of their head. c)they use ongoing disparity to determine azimuth of sounds. d)their left ear opens downward e)they do not have neocortex f)all of the above are true of owls.

e) they do not have neocortex (is false, bc they do)

In birds, each eye:

each eye sends axons completely across the thalamus, so the optic tectum represents entire eye

Castes: Quite clear that queen is physically different. When queen takes the throne, she develops an __________

elongated spinal column

bees know how far they've flown by:

energetics. ex. how much energy does it take when you fly out & too flowers, how much metabolic activity did you experience to do this. -tested this by tying weight to make bees trip more energetic, and then compared to bee with no weight, put food dish out, and saw they both go same distance for food, but see that bee with weight does a longer waggle -also another experiment, bees who go uphill, more energetics, longer waggle time.

In which structures would you be likely to find neurons phase locked to auditory stimuli? a)Nucleus Angularis b)Nucleus Magnocellularis c)Nucleus Laminaris e)The superficial layer of the optic tectum f) a & b g)b & c h)c & d

g) b & C Nucleus Magnocellularis & Nucleus Laminaris

Water shrews use which cues to find prey underwater? a)water movements b)prey shape c)smell d) a&b e)b&c f)a&c g)all of the above

g)all of the above (water movements, prey shape, and smell)

superior colliculus (midbrain)=

head & eye movements

what is optic flow?

how much of a visual scene passes through, translated through retina in a given amount of time. ex. driving a car & look at moon, doesnt appear to move as car goes in straight line, mountain slowly moving, nearby trees and poles much faster -all of these translate differently over retina based on their distance from you -closer you are to the object of interest, the faster things appear to move (insects dont have binocular vision)

cell will only response if sound is right in front of the animal bc

if you move it to the side, AP from one side will hit it & coincide with AP from the other side not at the cell

six eye muscles are controlled by 3 cells groups (nuclei)...where?

in the mid midbrain & hindbrain (cranial nerves III, IV, VI).

bees can account for the time it takes to travel to the hive & allow for sun movement by their______

internal chronometer

If turtle goes the right way away from the shore:

it goes in a backwards circular motion with wave

If turtle goes the wrong way back to the shore:

it goes in a forward circular motion with wave

bees centering response: if you let a bee fly down a tunne, it flies down the middle. how does it know to stay in center?

keeps optic flow equal in both eyes so speed of translation is the same -if gets too close to 1 wall, flow speeds up -equalized optic flow & takes the safest route (center, so it realized when it gets too close to a wall) -allows for safer navigation

earplug test with barred owls, soft vs hard earplug, to test timing cues & intensity cues: researchers

knudsen & konishi

researchers who worked on owl auditory system

konishi & knudsen

tunnel experiment with bees:srinivasan, 4 conditions

large amount of optic flow with vertical stripes in tunnel, bee experiences 5m of optic flow & thinks it flies 200m -(video in class, if camera closer to floor, looks faster, but if further away, looks like camera moving slower) -once bee enters tunner, completely diff visual climate for it, so walls are interpreted as a longer distance, relative to traveling 6 meters in a normal environment with less optic flow -but doesnt matter that bee interprets amount of distance wrong, bc all bees do the same thing,

when waves are simulated to come from right, they'll turn ___

left

in human brain:

left half of visual field is processed by right half of brain & right half processed by the left

cones

less sensitive, but used for higher resolution vision during the day & also for color in some species

areas where things are closer to the bee (bees that fly over a stream with vegetation close in, like the artificial tunnel, or a forested area), will have _____ waggle dances.

longer

rods

low levels of illumination, saturated & turned off during normal day

bird acuity:

many birds have 2 foveas, have amazing acuity, birds have way better acuity

see-saw hypothesis

misinterpretation of the anatomy of the visual system in birds & some mammals, led to the pseudo-evolutionary hypothesis that the geniculostriate system & the tectal systems are inversely related -a large tectum supposedly associated with a small geniculostriate & vice versa (but know that this hypothesis is false, by Irving Diamond, Tectum & Geniculostriate system vary inversely.

Do sea turtles have the ability to know what isoinclination lines & magnetic fields etc are instinctively or learn what they are as they navigate?

must be able to put angle & intensity together.complicated but they can do it. they know an island is somehwere along this isoline. itll hit the line and then turn right to turn to island. so not really a distinct gps signal, but allows them navigational feats that help them navigate.

in the middle of bird eye have ____, which sits like a sliver & is responsible for:

pecten, responsible for nourishing retina of birds -pecten gives uninterupted vision -birds dont have blood vessels underlying like we do, so they can see better -circadian oscillations also important in birds

Homonculus (human map of touch), tonotopic maps are represented in:

primary auditory cortex

In primates, all visual information from the retina critical to conscious perception travels through the:

primary visual cortex retina->lateral geniculate nucleus->primary visual cortex (areas 17,VI)->area 18, V2->V4 \ / MT

pretectum (midbrain)=

pupillary reflexes & accommodation (changes in lens shape)

when waves are simulates to come from left, sea turtles turn ____

right

two types of receptors in mammals:____ & ____

rods & cones -in mammalian eye, have blood vessels that give nutrients, but also abstract out view, except for the fovea, which allows us to see.

one of the first researchers to look at how owls found prey at night

roger payne

if food source of honeybees is 50m or less away, what dance do they do?

round dance

some mammals actually have a large optic tectum or superior colliculus such as:

scandentia: tree shrew

if live in open area, with less optic flow you're going to have a _____ waggle dance for the same distance

shorter

Logical conclusion about birds visual system

since birds can do so many comparable tasks w/ their visual system, they must be doing it with different structures than those used in mammals, specifically, the big optic tectum of birds does all the operations that mammals do with their visual cortex

researcher who also studied owls & not just bats

spallazani

Retinal ganglion cells in the eye sends axons to different brain areas

thalamus (LGN)->visual cortex / eye->hypothalamus \ (midbrain) pretectum & superior colliculus

what is the 8th cranial nerve

the auditory nerve

basic job of retina

translates the photons received by the receptors into signals that go to the brain that emphasize contrast, either spatial or temporal contrast

Sea turtle example of imprinting= ability to move with magnetic field

use light & wave to head away from beach, determine magnetic field orientation & use it to continue in that direction. will allow them to continue offshore so that they can make it to atlantic gyre

The visual systems of animals are designed to provide:

useful info for survival & reproduction, not to represent "reality"

dance floor:

vertical surface in the hive, where they hang out waiting to see if scouts found food

what is the dominant sense in owls

vision

How do sea turtles know where to go? -blindfolded newborn turtles cannot find ocean, so what does that tell you:

visual cue --> avoid dark areas that would be the dunes, they move toward light bc the sky over the ocean is lighter than the sky over land

if food source of honey bees is greater than 50m away, what dance is done?

waggle dance

Waggle duration vs. distance:

waggle more the further the distance

Sea turtles: temperature determined-sex: warmer eggs are ____. cooler eggs are ____.

warmer eggs are female (closer to sun) cooler eggs are male (furthest away from sun)

Physical differences in mole-rats which was first definitive finding of a caste:

with each pregnancy of naked-mole rat queen, her vertebrae got long & longer, thought happens bc she has to patrol the tunnels to maintain dominance. If she got wider & wider with pregnancy, would have to expand the whole tunnel system to get around, so instead gets longer & longer=first finding of definitive caste

NM:

wrap around cell body, hug it in big synapse -fast responsive glutamate receptors within NM cells (deactivate very quickly) -fast responsive voltage gates K channels -precise onset of AP, also fast & precise offset -want this for high fidelity connections -when AP arives, postsynaptic AP is very intune with presynaptic -unusual to have such number of specializations

Visual perception depends on experience & on context:

your retinal receptors respond to photons, but your brain interprets what you see