33 Brain & Behavior X

Question 1

Label this neuron

Answer 1

1. Dendrites
2. Cell body/Soma
3. Nucleus
4. Myelin sheaths

Question 2

Function of DENDRITES

Answer 2

RECEIVE information from OTHER neurons

Question 3

Function of axon

Answer 3

TRANSMIT nerve impulses

Question 4

What is at the END of an axon?

Function?

Answer 4

Axon Terminals

= Release information to the DENDRITES of other neurons

Question 5

Difference between MYELINATED and NON-myelinated neurons?

(What TISSUE TYPE do they give rise to?

Answer 5

Myelinated = WHITE matter

Unmyelinated = GREY matter

Question 6

Name the TYPES of neurons

Answer 6

1. MOTOR neurons
2. SENSORY neurons
3. INTERneurons

Question 7

Describe the ROUTE of motorneurons

Answer 7

CNS

Spinal cord

Muscle fibres

Question 8

ROUTE of sensory neurons

Answer 8

SENSE organ

Spinal cord

CNS (brain)

Question 9

Function of INTERneurons

Answer 9

BETWEEN neurons, large COMPUTATIONAL burden

Question 10

90% of the cells in the brain are whay type?

Answer 10

90% are GLIAL cells

Question 11

FUNCTION of glial cells

Answer 11

1. Scaffold for GROWING neurons
2. Scaffold and REPAIR of MATURE neurons

Question 12

What is the RESTING potential in neurons?

Answer 12

-70mV

(NEG on the INSIDE)

Question 13

What allows exceeding of the excitation THRESHOLD?

What is the threshold?

Answer 13

A PULSE exceeds the threshold of -55mV

Question 14

What happens when the threshold -55mV is exceeded?

Answer 14

ACTION POTENTIAL occurs

Question 15

How is the RESTING potential maintained?

Answer 15

OUTward Na⁺ channels OPEN

INward Na⁺ channels CLOSED

= keep inside NEG

Question 16

What happens when a PULSE exceeding the threshold is applied?

Answer 16

INward Na⁺ channels OPEN

= Na⁺ flows IN

= DEPOLARISATION

Question 17

How is homeostasis restored once the AP leaves?

Answer 17

K⁺ OUT of cell = restore -70mV

Question 18

The place where one neuron meets another is called

Answer 18

Synapse

(Axon terminals meet Dendrites)

Question 19

2 types of APs and their effect on the receiving neuron?

Answer 19

INHIBITORY = inhibit firing

EXCITATORY = induce firing

Question 20

What happens once the AP arrives at the axon terminal?

Answer 20

Release of neurotransmitters from vesicles into synaptic SPACE

= bind to POSTsynaptic receptors

= either inhibit/excite next neuron

Question 21

Explain the Lock-and-Key model of NT binding

Answer 21

Specificity

NTs only bind to specific receptors

Question 22

What happens to the NTs in the synaptic space AFTER an AP, to restore homeostasis?

Answer 22

1. Enzyme degradation = inactivated
2. Reused via synaptic reuptake

Question 23

What are the 3 proccesses that DRUGS can act on at the SYNAPSE to affect activity?

Answer 23

1. Stimulate/Inhibit NT release
2. Stimulate/Inhibit POSTsynaptic RECEPTORS
3. Inhibit reuptake

Question 24

Name 2 substances that affect NT release

Answer 24

1. Black widow VENOM = constitutive ACh release
2. Botulinum toxin = inhibit ACh release

Question 25

Effects of black spider VENOM

Answer 25

_ACh **AGONIST**_ = constitutive ACh release = **EXHAUST** ACh stores = Paralysis/Death in small animals, **abdominal pain** in humans

Question 26

Botulinum toxin is present in...

Answer 26

Improperly **CANNED food**

Question 27

Effect of botulinum toxin?

Answer 27

_ACh **ANTAGONIST**_ = inhibit ACh release = paralysis + suffocation

Question 28

Name drugs that stimulate/inhibit **POSTsynaptic RECEPTORS**

Answer 28

**Nicotine** stimulates **ACh** receptors **Curare** inhibits **ACh** receptors

Question 29

Effect of nicotine in low vs high doses?

Answer 29

LOW = Pleasure, addiction, excitatory HIGH = convulsions + DEATH

Question 30

Curare blocks ACh receptors in what tissue?

Answer 30

Curare blocks ACh receptors on **MUSCLE fibres**

Question 31

Effect of inhibiting ACh **reuptake**?

Answer 31

Prolonged + Increased effect of ACh

Question 32

Name drugs that inhibit **reuptake** What NTs do they inhibit the reuptake of?

Answer 32

**_Amphetamines + Cocaine_** = AGONISTS of dopamine, norepinephrine, epinephrine = affects **_autonomic arousal_** = restlessness, insomnia, euphoria

Question 33

Name an **_antidepressant_** and its MoA

Answer 33

**_Prozac_** = block reuptake of **serotonin** = relieves depression

Question 34

Name a **benzodiazepine** and its MoA

Answer 34

**_Valium_** =**GABA** agonist = reduces anxiety, helps sleep

Question 35

MoA of **heroin**

Answer 35

**AGONIST** = MIMICS **_endorphins_** at postsynaptic receptor = feels good, euphoria, sedation