Excitatory and Inhibitory Neurotransmission

Question 1

Difference between an ionotropic receptor and a metabotropic receptor?

Answer 1

Ionotropic receptor = the receptor is the channel
(think Iono-iONEo)

Metabotropic receptor = the receptor and the channel are separate

Question 2

These channels are tetramers

Answer 2

Glutamate

Question 3

These channels are pentamers

Answer 3

GABA, Glycine, nicotine

Question 4

What channel does ketamine block?

Answer 4

NMDA

Question 5

What channel does phencylidine block?

Answer 5

NMDA

Question 6

What does GABA-A receptor operate? (this is an ionotropic receptor)

Answer 6

The Cl- channel

Question 7

What does the GABA-B receptor operate? (This is a metabotropic receptor)

Answer 7

The potassium channel

Question 8

Which type of drugs are positive allosteric receptors of GABA-A receptors?

Answer 8

Benzodiazepines

= enhance Cl- entry =decrease rmp = enhance inhibitio in presence of GABA

Question 9

Similar to benzodiazepines and potentiates the effect of GABA at the GABAA receptor

Answer 9

Barbiturates

Question 10

agonist of the GABAB receptor so enhances the K current (and increases inhibition)

Answer 10

Baclofen

Question 11

Which transmitter acts on the glycine ionotropic receptor? And what channel does it gate?

Answer 11

• Glycine

- Cl- channel

Question 12

This is released by interneurones in spinal cord to inhibit antagonist muscles motorneurones

Answer 12

Glycine

Question 13

the major excitatory neurotransmitter, acts on ionotropic receptors to allow Na and Ca in and K out of the cell, net result is an EPSP, depolarization, and excitation

Answer 13

Glutamate

Question 14

the major inhibitory neurotransmitter, acts on ionotropic receptors to allow Cl into the cell, net result is an IPSP, hyperpolarization, and inhibition

Answer 14

GABA

Question 15

a locally-acting neurone, typically releases GABA and so brings about an IPSP and inhibition, function is local processing of information

Answer 15

Interneurone

Question 16

a neuron responsible for conveying signals to other parts of the brain, typically releases Glutamate and so brings about an EPSP

Answer 16

Projection neurone

Question 17

What is spatial summation?

Answer 17

EPSPs and IPSPs are spatially distributed but timed together

i.e. all the excitation/inhibition occurs at once

Question 18

What is temporal summation?

Answer 18

EPSPs occur in temporal sequence such that threshold is triggered
(i.e. might be excited-then inhibited then excited then excited , the potentials arrive one after the other instead of all at once)