W3

Question 1

What is neural integration?

Answer 1

the idea that many PrSN contact many PoSN and many PoSN recieve inputs from many PrSN so PoSN integrate across many inputs - increasing probability of PoSN firing AP cause my hypo/hyperpolarisation

Question 2

What is a Ligand?

Answer 2

chemical that ineracts with a receptor (NT is one)

Question 3

What is affinity?

Answer 3

how well a ligand binds to a receptor - high affinity = small amount ligands binds to almost all receptors

Question 4

What is an ionotropic receptor?

Answer 4

type of receptor - directly coupled/is an ion channel = when ligand binds to this receptor the ion channel opens as a direct effect of the NT on the conductance of the PoSN

Question 5

what is a metabotropic receptor?

Answer 5

1. lignad binds to receptor - Because NT is least into the synaptic cleft = binds to the receptor on the outside of the PoSN membrane
2. this changes the 3D shape of the receptor - Because recepter proteins span the bi layer of the membrane = change in shape is also seen on internal surface of membrane
3. Inside membrane the recepter proteins are coupled/connected to other types of proteins so the change in shape activates these other proteins = G-protein
4. this activates an intracellular signalling cascade which can alter ionotropic receptors and alter protein synthesis

Question 6

Types of NT - Amino Acid Derivatives

Answer 6

1. Glutamate
   - derived from glutamic acid
   - most abusdant
   - EPSP’s (excitatory)
2. GABA
   - made from glutamate
   - inhibitory - less likely to fire AP
   - binds to both types of GABA receptors
3. Glycine
   - unusual as its an amino acid itself

Question 7

Types of NT - Monoamines

Answer 7

• bind to metabotropic receptors
• found in very specific groups of neurons

1. Dopamine
2. Serotonin
3. Neuropeptides - proteins that act as NT eg opiods

Question 8

LTP - NMDA receptors for induction

Answer 8

• type of glutamate receptor
• needed for LTP to happen - need NMDA receptors for learning = LTP is mechanism for learning
• ionotropic receptor = sodium and calcium go into the cell
• glutamate binds so cell membrane is depolarised and magnesium ion block removed and calcium can enter

Question 9

LTP - AMPA receptor for expression of LTP

Answer 9

• NMDA receptors no longer needed after initial induction of LTP
• ionotropic receptor = EPSPs
• when NMDA receptors are activated to induce LTP then this results in more AMPA receptors in the membrance - activation cascade

Question 10

what is long-term depression?

Answer 10

• still a mechanism of learning
• decrease in the response to the same input
• observed normally when there is low frequency stimulation (1Hz)

Question 11

what is synaptic plasitcity

Answer 11

the output response to an input can change