Nervous System Control of Behavior

Question 1

Nerve Net

Answer 1

few neurons, minimal density, sparse connections; no “brain,” but still perform simple behaviors, like response to environmental stimuli

Nerve Net Example: simple invertebrates (w/radial symmetry) -> Jellyfish

Question 2

Complex Nervous System

Answer 2

as the name says, more complex lol, greater number of neurons, other cell types present, greater density; more robust connections; has “brain” and specialized neurons that respond to specific stimuli

Complex nervous system examples: vertebrates (so mammals, birds, amphibians)

Question 3

Santiago Ramon y Cajal

Answer 3

Histologist

Saw cells of various shapes and sizes, predicted they had different purposes (and was right!), did the research before humans had knowledge of neurons; had extensively detailed drawings of neurons

Question 4

Name the parts of the neuron and its function

Answer 4

Parts: nucleus, cell body, dendrites, axon, myelin sheath, axon terminal

Question 5

Cell body

Answer 5

soma, responsible for electrical signal generation

Question 6

Dendrites

Answer 6

where chemical info is received

Question 7

Axon

Answer 7

transmits electrical signals

Question 8

Myelin Sheath

Answer 8

a type of fat that wraps around the axon to speed up an electrical signal

Question 9

Axon terminal

Answer 9

where a signal exits a neuron to the designated part of the body (an example being muscle)

Question 10

Describe neuron process/function

Answer 10

info enters dendrites, goes through cell body, to axon/myelin sheath, and exits at the axon terminal

Question 11

Name the 3 categories of neurons

Answer 11

multipolar, bipolar, and unipolar

Question 12

Multipolar Neuron

Answer 12

major cell type of complex neurons system, produce more complex behaviors

Question 13

Bipolar neuron

Answer 13

processes sensory info, seen in vertebrates and higher order invertebrates

Question 14

Unipolar neuron

Answer 14

most simple neuron type, processes simple behaviors (nothing complex), associated with nerve nets, seen in simple invertebrates

Question 15

Describe the research of Dr. Kenneth Roeder

Answer 15

Ultrasonic processing in moths

Saw it Outside of the CNS(central nervous system), local circuit

Accompolished by pattern generator (NOT BRAIN); brain modulates but does not control this

Figured out moths can hear echolocation of bats, their main predator, through A1 and A2 receptors

Question 16

Describe experiments done by Dr. Kenneth on A1 and A2 receptors

Answer 16

Activation of A1 and A2 sustained

Moths exposed to volume increasing in intensity; Central pattern generator normally responsible for rhythmic movements, inhbiting this creates erractic wing beats/flying

This will throw off the pattern the bat(predator) would expect

If the bat is not fooled: Continued activation of A1 and A2, or Complete shutdown of central pattern generator (then bat cannot detect moth)

Question 17

Central pattern generators

Answer 17

responsible for rhythmic movements

Question 18

Aplysia

Answer 18

aquatic species aka the sea hare

has unipolar neurons

displayed to have learning ability in research

Question 19

Describe the research of Dr. Eric Kendel

Answer 19

showed Aplysia has learning ability to an extenet

showed learning of habituation and sensitization in Aplysia

Question 20

Aplysia habiutation

Answer 20

When the Aplysia is poked, the sensitive parts of the body are draw in/back towards the body (gills, head); once it goes back to “normal, “ this is repeated

Eventually displays habituation (no response to poking)

Question 21

Neurotransmitters of Aplysia under normal conditions

Answer 21

Vesicles and neurotransmitters are just waiting for signals

Electrical signals are sent down the axon

Signals bring in Calcium ions into the channels

Then capsules work as chemical messengers (neurotransmitters), to cross the synapse to the motor neuron it will activate

Question 22

Neurotransmitters under habituation in Aplysia

Answer 22

The voltage gated Calcium ion channels will not open

The electrical signal stops there, will then not allow capsules to release chemical messages

Note: remember these signals are ALL OR NOTHING signals; This means poking harder does not change effect, voltage stays the same and does not open ion channels

Question 23

Sensitization in Aplysia

Answer 23

they receive a poke and then are shocked (done with strong continuity); they will then flinch after a poke since they expect a shock to follow

Question 24

Describe one neurotransmitter pathway of sensitization in Aplysia

Answer 24

Poking and shocking releases serotonin 5-HT, G-coupled 5-HT receptor grabs onto serotonin 5-HT in axon

Serontonin 5-HT has three major parts: the alpha section moves on to Adenylate cyclase (other areas don’t matter here); Alpha section and Adneylate cyclase create the cyclic AMP (2nd messenger); This leads to protein kinase

Protein kinase phosphorylates (adds phosphate group) potassium channels; This changes potassium channel states (in this case on -> off, open -> close, but can go either way); Phosphorylated potassium channels stay closed longer

Overall, the electrical signal will have no where to go, since channels are closed; the longer they are closed, the longer the calcium ion channels are open

Question 25

Name another pathway of neurotransmitters in sensitization in Aplysia

Answer 25

Poking and shocking releases serotonin 5-HT; G-coupled 5-HT receptor grabs onto serotonin 5-HT in axon

Serontonin 5-HT has three major parts: the alpha section moves on to phospholipase C (other areas don’t matter here); Alphas section and phospholipase C create the DAG(diacylglycerol); This leads to protein kinases

Protein kinase phosphorylates calcium ion channels and synapsin activates; This changes their state from off -> on, close -> open

Syapsin facilitates movement of vesicles and capsules

Question 26

Neuron

Answer 26

send and receive electrical & chemical info; receive chem, send electrical

Question 27

Glia

Answer 27

10x more numerous than neurons, support the function of neurons

Question 28

Interneurons

Answer 28

: modulate (fine tune) signaling by neurons

Question 29

Cerebellum

Answer 29

responsible for fine motor activities

Size/distinguishable-ness of it increases from reptile to bird to cat to human

Question 30

Olfactory lobe/bulb

Answer 30

responsible for sense of smell

Near front of face in vertebrates (which makes sense lol)