Lecture 1

Question 1

What do dendrites do? And what direction does the info travel- towards or away from the axon?

Answer 1

Receive info from other neurons or sensory receptors. Info travels towards the axon

Question 2

What are some structures the soma contains?

Answer 2

Nucleus, mitochondria, endoplasmic reticulum, ribosomes, Golgi complex, cytoplasm, microtubules

Question 3

What is the axon? What does it carry info to/from?

Answer 3

The long tube that carries information (action potentials). Carries info FROM cell body TO terminal buttons

Question 4

What are the terminal buttons?

Answer 4

They secrete the neurotransmitter to the synaptic cleft

Question 5

Definition of a chemical synapse

Answer 5

Specialised junction between 2 neurons- or a neuron and a target cell, which allows for the transmission of information via chemical signalling

Question 6

What is the definition of the soma

Answer 6

The cell body; central part of the neuron, contains the nucleus and majority of cellular machinery. Integrates incoming signals from dendrites and determines if they are strong enough to generate action potentials

Question 7

What is the fatty insular which is produced by glial cells called? And what are the cells?

Answer 7

Myelin; oligodendrocytes in the peripheral nervous system and Schwann cells in the CNS

Question 8

What is the function of Tau proteins?

Answer 8

Proteins with the function to stabilise and maintain the structure of a neurons microtubules, in neurodegenerative diseases, these can be abnormally modified, causing neurofibrillary tangles, ultimately disrupting neuronal function

Question 9

What is the difference in morphology between a chemical and electrical synapse

Answer 9

Chemical has asymmetric morphology, Electrical has symmetric

Question 10

What is the difference in direction between a chemical and electrical synapse

Answer 10

Chemical is unidirectional, electrical is bidirectional

Question 11

What is the modulation / plasticity difference in chemical and electrical synapses?

Answer 11

Chemical - high modulation / plasticity
Electrical - low modulation / plasticity

Question 12

What is the synaptic delay like for chemical and electrical synapses?

Answer 12

Chemical - slow synaptic delay (milliseconds)
Electrical - extremely fast, virtually no delay

Question 13

What are the differences in strength at a chemical and electrical synapse

Answer 13

Chemical - variable strength
Electrical - fixed or limited strength

Question 14

What is the difference in size between a synaptic cleft and a gap junction?

Answer 14

Synaptic cleft - 20-40nm
Gap junction - 2-4nm

Question 15

What is the difference between molecular specificity at a chemical and electrical synapse?

Answer 15

Chemical - high molecular specificity
Electrical - low molecular specificity

Question 17

What are astrocytes?

Answer 17

Astrocytes are star-shaped glial cells in the brain that support neurons and maintain the blood-brain barrier.

Question 18

True or False: Oligodendrocytes are responsible for myelinating axons in the central nervous system.

Answer 18

True

Question 19

Fill in the blank: Microglial cells act as the _____ of the brain, responding to injury and disease.

Answer 19

immune cells

Question 20

What is the primary function of astrocytes?

Answer 20

To provide structural support, regulate blood flow, and maintain homeostasis in the brain.

Question 21

Multiple Choice: Which type of glial cell is involved in the formation of the myelin sheath in the central nervous system? A) Astrocytes B) Oligodendrocytes C) Microglia

Answer 21

B) Oligodendrocytes

Question 22

What role do microglial cells play in the brain?

Answer 22

They act as the brain’s immune defense, clearing away dead cells and debris.

Question 23

True or False: Astrocytes can influence neurotransmitter levels in the brain.

Answer 23

True

Question 24

What is the primary difference between oligodendrocytes and Schwann cells?

Answer 24

Oligodendrocytes myelinate axons in the central nervous system, while Schwann cells do so in the peripheral nervous system.

Question 25

Fill in the blank: The blood-brain barrier is primarily maintained by _____ cells.

Answer 25

astrocytes

Question 26

What is the function of oligodendrocytes?

Answer 26

To produce myelin, which insulates axons and increases the speed of electrical impulses.

Question 27

Multiple Choice: Which glial cell type is primarily responsible for repairing brain tissue after injury? A) Astrocytes B) Oligodendrocytes C) Microglia

Answer 27

A) Astrocytes

Question 28

True or False: Microglial cells proliferate in response to brain injury.

Answer 28

True

Question 29

What do astrocytes release to influence neuronal activity?

Answer 29

They release neurotransmitters and other signaling molecules.

Question 30

Fill in the blank: Oligodendrocytes can myelinate _____ axons at once.

Answer 30

multiple

Question 31

What is the role of microglial cells in neurodegenerative diseases?

Answer 31

They can become activated and may contribute to neuroinflammation and neuronal damage.

Question 32

Multiple Choice: Which glial cell type is derived from the neuroectoderm? A) Astrocytes B) Oligodendrocytes C) Both A and B

Answer 32

C) Both A and B

Question 33

What is the primary signaling molecule released by astrocytes?

Answer 33

Glutamate

Question 34

True or False: Microglia are the most abundant type of glial cell in the brain.

Answer 34

False

Question 35

What happens to oligodendrocytes during multiple sclerosis?

Answer 35

They are damaged, leading to demyelination of axons.

Question 36

Fill in the blank: Astrocytes can help regulate _____ levels in the extracellular space.

Answer 36

potassium

Question 37

What is the role of astrocytes in synaptic function?

Answer 37

They help modulate neurotransmitter uptake and recycling at synapses.

Question 38

Multiple Choice: Which type of cell can become phagocytic in response to brain injury? A) Astrocytes B) Oligodendrocytes C) Microglia

Answer 38

C) Microglia

Question 39

True or False: Oligodendrocytes can regenerate after injury.

Answer 39

False

Question 40

What is the function of the myelin sheath?

Answer 40

To insulate axons and increase the speed of electrical impulses along the nerve fibers.

Question 41

Fill in the blank: Microglial cells have a role in _____ monitoring in the brain.

Answer 41

immune

Question 43

What are the primary ions involved in neuronal communication?

Answer 43

Sodium (Na+), Potassium (K+), Calcium (Ca2+), and Chloride (Cl-).

Question 44

True or False: The resting membrane potential of a neuron is typically around +30 mV.

Answer 44

False. The resting membrane potential is typically around -70 mV.

Question 45

Fill in the blank: During an action potential, the influx of ______ ions causes depolarization.

Answer 45

Sodium (Na+)

Question 46

What is the role of potassium ions (K+) in repolarization?

Answer 46

Potassium ions (K+) exit the neuron, helping to return the membrane potential to its resting state.

Question 47

Multiple choice: Which ion is primarily responsible for neurotransmitter release at synapses?

Answer 47

Calcium (Ca2+)

Question 48

What term describes the difference in ion concentration across a neuronal membrane?

Answer 48

Ion gradient.

Question 49

True or False: Chloride ions (Cl-) typically flow into the neuron during hyperpolarization.

Answer 49

True.

Question 50

What is the main function of the sodium-potassium pump in neurons?

Answer 50

To maintain the resting membrane potential by pumping 3 Na+ out and 2 K+ in.

Question 51

Short answer: Describe the role of ion channels in neuronal communication.

Answer 51

Ion channels allow the selective passage of ions across the neuronal membrane, facilitating changes in membrane potential.

Question 52

Fill in the blank: The ______ period is the time following an action potential during which a neuron cannot fire another action potential.

Answer 52

Refractory

Question 54

What is the resting potential of a neuron?

Answer 54

The resting potential of a neuron is the electrical charge difference across the cell membrane when the neuron is not actively transmitting a signal, typically around -70 mV.

Question 55

True or False: Action potential occurs when the membrane potential reaches a threshold level.

Answer 55

True

Question 56

Fill in the blank: During depolarisation, the membrane potential becomes __________.

Answer 56

more positive

Question 57

What is hyperpolarisation?

Answer 57

Hyperpolarisation is the increase in membrane potential, making the inside of the cell more negative than the resting potential.

Question 58

Multiple Choice: Which of the following best describes depolarisation? A) Decrease in membrane potential B) Increase in membrane potential C) No change in membrane potential

Answer 58

B) Increase in membrane potential

Question 60

What is the primary function of the sodium-potassium pump?

Answer 60

To maintain the electrochemical gradient by transporting sodium out of the cell and potassium into the cell.

Question 61

True or False: The sodium-potassium pump moves three sodium ions out of the cell for every two potassium ions it moves in.

Answer 61

True

Question 62

Fill in the blank: The sodium-potassium pump is an example of a __________ transport mechanism.

Answer 62

active

Question 63

What role do voltage-gated channels play in action potentials?

Answer 63

They open in response to changes in membrane potential, allowing ions to flow across the membrane.

Question 64

Which ion primarily flows through voltage-gated sodium channels during the depolarization phase of an action potential?

Answer 64

Sodium (Na+)

Question 65

During which phase of the action potential does repolarization occur?

Answer 65

After the peak of the action potential.

Question 66

What causes the hyperpolarization phase of an action potential?

Answer 66

The continued outflow of potassium ions through voltage-gated potassium channels.

Question 67

True or False: Ion permeability changes during an action potential due to the opening and closing of ion channels.

Answer 67

True

Question 68

Multiple Choice: What initiates the depolarization phase of an action potential?

Answer 68

A: Opening of voltage-gated sodium channels

Question 69

Which ion has a higher concentration inside the cell at rest?

Answer 69

Potassium (K+)

Question 70

Fill in the blank: The resting membrane potential of a neuron is typically around __________ mV.

Answer 70

-70 mV

Question 71

What is the threshold potential for initiating an action potential?

Answer 71

Approximately -55 mV.

Question 72

True or False: After an action potential, the sodium-potassium pump helps restore the resting membrane potential.

Answer 72

True

Question 73

What is the significance of the refractory period during an action potential?

Answer 73

It prevents the generation of another action potential too soon and ensures unidirectional signal propagation.

Question 74

During the action potential, what happens to the membrane potential during the depolarization phase?

Answer 74

It becomes more positive.

Question 76

What is the absolute refractory period?

Answer 76

The absolute refractory period is the time during which a second action potential cannot be initiated, regardless of the strength of the stimulus.

Question 77

True or False: During the relative refractory period, a stronger-than-normal stimulus can initiate an action potential.

Answer 77

True

Question 78

Fill in the blank: The absolute refractory period occurs during the ______ phase of the action potential.

Answer 78

depolarization

Question 79

What ion channel activity primarily determines the absolute refractory period?

Answer 79

Inactivation of sodium (Na+) channels

Question 80

Multiple choice: Which of the following best describes the relative refractory period? A) No action potential can occur B) Action potential can occur with a stronger stimulus C) Only depolarization occurs D) It lasts longer than the absolute refractory period

Answer 80

B) Action potential can occur with a stronger stimulus

Question 82

What is meant by 'neuronal firing rate'?

Answer 82

The frequency at which a neuron generates action potentials, typically measured in Hertz (Hz).

Question 83

True or False: A higher firing rate of a neuron generally indicates a stronger stimulus.

Answer 83

True

Question 84

Fill in the blank: A higher firing rate can be associated with ______ intensity of the stimulus.

Answer 84

greater

Question 85

What is 'saltatory conduction'?

Answer 85

The process by which action potentials jump from one node of Ranvier to another along myelinated axons.

Question 86

Multiple Choice: What is the primary benefit of saltatory conduction?

Answer 86

It increases the speed of electrical signal transmission.

Question 87

How does myelination affect neuronal speed?

Answer 87

Myelination increases the speed of action potential propagation along the axon.

Question 88

What unit is commonly used to measure neuronal firing rate?

Answer 88

Hertz (Hz)

Question 89

True or False: Neurons can fire at a constant rate regardless of the stimulus intensity.

Answer 89

False

Question 90

What happens to the speed of conduction in unmyelinated axons compared to myelinated axons?

Answer 90

The speed of conduction is slower in unmyelinated axons.

Question 91

Define 'intensity' in the context of neuronal firing.

Answer 91

The strength of the stimulus that influences the rate of neuronal firing.

Question 92

How do anaesthetics work in the brain?

Answer 92

- block Na+ channels or open K+ channels -preventing depolarisation and action potential generation -so can inhibit electrical signalling in neurons

Question 93

How do sedatives work in the brain?

Answer 93

-enhance inhibitory neurotransmitter receptors eg GABA receptors - so can increase neuronal hyperpolarisation, calming neuronal activity, reducing anxiety or agitation

Question 95

What is a chemical synapse?

Answer 95

A chemical synapse is a junction between two neurons where neurotransmitters are released to transmit signals.

Question 96

True or False: Chemical synapses use electrical impulses to transmit information.

Answer 96

False

Question 97

Fill in the blank: The gap between the presynaptic and postsynaptic neurons is called the _______.

Answer 97

synaptic cleft

Question 98

What role do neurotransmitters play in a chemical synapse?

Answer 98

Neurotransmitters are chemicals that transmit signals across the synaptic cleft from one neuron to another.

Question 99

Which part of the neuron releases neurotransmitters?

Answer 99

The presynaptic terminal

Question 100

What happens to neurotransmitters after they bind to receptors on the postsynaptic neuron?

Answer 100

They can either trigger a response or be reabsorbed or broken down.

Question 101

Multiple choice: Which of the following is NOT a type of neurotransmitter? A) Dopamine B) Serotonin C) Myelin D) Acetylcholine

Answer 101

C) Myelin

Question 102

What initiates the release of neurotransmitters from the presynaptic neuron?

Answer 102

An action potential arriving at the presynaptic terminal.

Question 103

True or False: All neurotransmitters have the same effect on the postsynaptic neuron.

Answer 103

False

Question 104

Fill in the blank: Neurotransmitters bind to _______ on the postsynaptic neuron.

Answer 104

receptors

Question 105

What is the function of calcium ions in neurotransmitter release?

Answer 105

Calcium ions facilitate the fusion of neurotransmitter-containing vesicles with the presynaptic membrane.

Question 106

Short answer: Name one common excitatory neurotransmitter.

Answer 106

Glutamate

Question 107

Short answer: Name one common inhibitory neurotransmitter.

Answer 107

GABA (gamma-aminobutyric acid)

Question 108

What is synaptic plasticity?

Answer 108

Synaptic plasticity is the ability of synapses to strengthen or weaken over time, in response to increases or decreases in their activity.

Question 109

Multiple choice: Which process describes the reuptake of neurotransmitters? A) Transport B) Degradation C) Diffusion D) All of the above

Answer 109

A) Transport

Question 110

True or False: Chemical synapses can only transmit signals in one direction.

Answer 110

True

Question 111

What is the role of the postsynaptic density?

Answer 111

The postsynaptic density is a specialized area that contains receptors and signaling molecules for neurotransmitter action.

Question 112

Fill in the blank: The process by which neurotransmitters are broken down by enzymes is called _______.

Answer 112

metabolism

Question 113

Short answer: What is the effect of an excitatory neurotransmitter on the postsynaptic neuron?

Answer 113

It increases the likelihood of an action potential.

Question 114

What is the main difference between chemical and electrical synapses?

Answer 114

Chemical synapses use neurotransmitters for signal transmission, while electrical synapses use direct electrical connections.