Post-synaptic terminals

Question 1

Why are multiple Na+ channels needed to create an AP [2]

Answer 1

opening of one channel increases mebreane to ~72mV

multiple needed to reach threshold/55mV

Question 2

Describe dendritic spines [5]

Answer 2

-many protrusions
-storage site for synaptic strength
-transmit electrical signals to soma
-allow for more specificity (localised)
-more influence the closer they are to the soma

Question 3

Describe L-glutamate [4]

Answer 3

-excitatory
-abundant
-VGLUT transports glutamate into vesicle
-dependent on Ca2+ release

Question 4

Compare AMPA and NMDA receptors [5]

Answer 4

-Mixture of Glue 1-4/mixture of GluN1 and GluN2
-usualalyy heterotetramers/ always heterotetramers
-High amplitude/slow rising
-short lived EPSP/long lasting
-day to day comms/specail conditions and plasticity

Question 5

Describe the Mg block as a coincidence receptors [4]

Answer 5

-NMDA voltage dependrnt
-Mg+ blocks channel
-removed at ~35mV
-therefore must a presynaptic change and glutamate for ions to flow through
-new circuit to be formed if repeated

Question 6

Describe GABA

Answer 6

inhibitory
-inotropic and metabotropic
-ca2+ dependent
-VGAT transfers GABA into vesicles
-found closer to hillock
-allows Cl- in (Hyperpolarisation)

Question 7

Compare GABAa and GABAb receptors

Question 8

Describe GABAb receptors

Answer 8

metabotropic
K+ out/ Cl- in
inhibits adrenal cyclase
slow IPSP

Question 9

Define the term auto-receptor

Answer 9

receptor found on presynaptic terminal
activated by neurotransmitters
released by that same synapse

Question 10

What is paired pre pulse depression

Answer 10

the previous AP means then the next AP will weaker

decrease in size of response of second AP

Question 11

Describe GABAa [2]

Answer 11

inotropic
fast IPSP

Question 12

Why does GABAb cause paired pre pulse inhibition [3]

Answer 12

-activatedby previous GABA release
-restricts calcium into cell
-calcium needed for GABA release
-less calcium means less GABA release