Synapses and Neural Integration

Question 1

What 2 ways can communication be measured in the brain?

Answer 1

1. Electrically (Neurophysiology) - looking at the flow of ions in the tissue
2. Chemically (Microdialysis) - Measurements of levels of chemicals or neurotransmitters in the brain

Question 2

Name 4 methods of neurophysiology, from lowest to highest spatial resolution

Answer 2

1. EEG
2. Multi-cell recording
3. Single cell recording
4. Intracellular

Question 3

What are the advantages and disadvantages of EEG?

Answer 3

Adv
- Non-invasive
- High temporal resolution 
- Can be used to study sleep, epilepsy & cognitive processes 
Disadv
- Can only record from the cortex
- Low spatial resolution

Question 4

What is multi-cell recording and how is it useful?

Answer 4

Can record groups of neurones in order to investigate local brain rhythms, such as the interactions of memory and attention in rats when making a decision. Ok temporal and spatial resolution.

Question 5

Why can intracellular recording sometimes be better than single cell recording?

Answer 5

Single cell recording only looks at the extracellular processes, by using intracellular recording we can examine the sub-cellular processes

Question 6

What are the 2 main types of receptor?

Answer 6

Ionotropic - Simple and quick, neurotransmitter flows through ion channel
Metabotropic - Complex and long lasting

Question 7

Describe the process of metabotropic receptors

Answer 7

Molecule binds to receptor which goes on to activate the G protein which then allows the alpha subunit to break away and open the ion channel. Alternatively, alpha subunit could activate enzymes and then go on to activate a secondary messenger

Question 8

What are the 2 types of neurotransmitters and give examples

Answer 8

Excitatory - causes depolarisation and action potentials, also known as ESPS e.g glutamate
Inhibitory - causes hyperpolarisation and inhibits action potentials, also called IPSP e.g GABA

Question 9

What are the 4 types of ion channel

Answer 9

1. Influx of Na+ causes depolarisation
2. Exflux of K+ causes hyperpolarization
3. Influx of Cl- causes hyperpolarization
4. Influx of Ca2+ activates an enzyme

Question 10

What is the point neurone hypothesis?

Answer 10

That each synapse has an equal weighting in its ability to make a neurone fire, and that the exitatory inputs must outweigh the exitatroy inputs

Question 11

What is the two compartment hypothesis?

Answer 11

That neurones are split into two functional compartments
1) The soma, basal dendrites and axon
2) Apical dendritic tree
Where the sum of the inputs from the apical dendrites are passed on to the soma