Lecture 1 - Neurons and Neurotransmitters

Question 1

The brain is the organ of …

Answer 1

Interpretation and prediction - continually taking in sensory data and integrating the into with previous experiences to then make predictions

Question 2

Pareidolia

Answer 2

seeing faces in inanimate objects

Question 3

Central nervous system

Answer 3

Brain and spinal cord

Question 4

Peripheral nervous system

Answer 4

Nerves - collects information from organs/muscles, carry information to muscles to carry out movement and allow organs to operate

Question 5

Four lobes of the human brain

Answer 5

Frontal lobe, parietal lobe, occipital lobe, temporal lobe

Question 6

Frontal lobe

Answer 6

decision making, executive function, high order processing, controlling behaviour

Question 7

Parietal lobe

Answer 7

helping body move through space

Question 8

Occipital lobe

Answer 8

visual system interpretation

Question 9

Temporal lobe

Answer 9

memory system - building memory and interpreting visual stimuli

Question 10

Brains processing units =

Answer 10

Neurons

Question 11

Neurons

Answer 11

neurons which are specialised nerve cells

Question 12

How many neurons in average human brain?

Answer 12

approx 85 billion in the average human brain - each makes 100-10000 connections with others and these connections are important for allowing you to store information and behave in different ways

Question 13

What is the key to information processing in the nervous system?

Answer 13

simple fact that the inside of a neuron is negatively charged compared to the outside i.e. neurons have a resting membrane potential of -70mV (sits at this when the neuron is not transmitting information)

Lots of positively charged sodium on the outside and lots of negatively charged anions on the inside which gives a negative charge on the inside compared to the outside

There are ion channels that move ions from inside to outside and outside to inside

Question 14

Information is transmitted within the neuron cell by….

Answer 14

transient alteration in the membrane potential (transmit information by small changes in membrane potential)

Question 15

Dendrites

Answer 15

Input

Question 16

Axon

Answer 16

output

Question 17

Graded potential

Answer 17

Within dendrites the pulse can vary in size i.e. it is a graded potential. Graded potentials are changes in membrane potential that vary in size, as opposed to being all-or-none. … The magnitude of a graded potential is determined by the strength of the stimulus.

Question 18

Temporal summation

Answer 18

Arrival of stimulus immediately after each other resulting in addition of them together

Where PSP’s that occur in quick succession add up/summate

Question 19

Spatial summation

Answer 19

Spatial = addition of multiple stimulus from multiple neurons to a single postsynaptic neuron

Where PSP’s from different areas of the input zone add up/summate

Question 20

Action potential

Answer 20

Within axons, this “pulse” is all or none (an action potential) depending upon whether it reaches a threshold level of intensity at the initial segment

Question 21

Difference of action potentials compared to graded potentials

Answer 21

AP occurs extremely rapidly and then is gone in a very short amount of time

AP can in mV is massive compared to graded potentials

Question 22

Tetrodotoxin (TTX)

Answer 22

Blocks ion flow through channels that generate action potentials

10000 times deadly than cyanide, found in puffer fish

Question 23

Neurons are the

Answer 23

basic building blocks of the nervous system

Question 24

three main parts of a neuron

Answer 24

dendrite, cell body (soma) and the axon

Question 25

Dendrites

Answer 25

specialised receiving unit

Question 26

Axons

Answer 26

conducts electrical impulses away from the cell body to other neurons, muscles or glands

Question 27

Glial cells

Answer 27

support cells of the nervous system

Question 28

Within the brain glial cells...

Answer 28

outnumber neurons about 10 to 1

Question 29

Nerve activation involves 3 basic steps

Answer 29

1 - at rest, the neuron has an electrical resting potential due to the distribution of positively and negatively charged chemical ions inside and outside the neuron 2- when stimulated, a flow of ions in and out through the cell membrane reverses the electrical charge of the resting potential, producing an action potential, or nerve impulse 3 - The original ionic balance is restored and the neruon is restored and the neuron is again at rest, ready to be stimulated again

Question 30

Ions in ECF and ICF

Answer 30

outside cell = high Na+, low K+ and high Cl- | inside cell = Low Na+, high K+ and low Cl-

Question 31

Resting membrane potential

Answer 31

internal difference of around -70mV

Question 32

At rest, the neuron is said to be in a state of

Answer 32

polarisation

Question 33

Action potential

Answer 33

Electrical shift of about -70mV to +40mV also called a nerve impulse

Question 34

Order of events in an action potential

Answer 34

resting membrane potential Depolarisation Action potential repolarisation

Question 35

sodium flows in =

Answer 35

depolarisation

Question 36

potassium flows out =

Answer 36

repolarisation

Question 37

Action potentials are

Answer 37

all or nothin

Question 38

Absolute vs relative refractory

Answer 38

``` absolute = no AP relative = can get AP but much harder to generate one ```

Question 39

Myelin sheath =

Answer 39

fatty insulation layer derived from glial cells during development

Question 40

Unmyelinated axons are what colour

Answer 40

grey in colour which is why it is called grey matter and myelinated axons are often called white matter

Question 41

Synaptic space

Answer 41

tiny gap between the axon terminal and the next neuron

Question 42

Neurotransmitters are

Answer 42

chemical substances that carry messages across the synaptic space to other neurons, muscles or glands

Question 43

Neurotransmitter examples

Answer 43

``` ACh Noradrenaline Serotonin Dopamine GABA Endorphin ```

Question 44

Drugs that block the action of ACh

Answer 44

can prevent muscle activation and cause paralysis

Question 45

Neuromodulators

Answer 45

Have more widespread and generalised influence on synaptic transmission