1.6 Cell Communication

Question 1

What are the 4 cell communication types

Answer 1

endocrine
autocrine
paracrine
juxtacrine

Question 2

Describe endocrine signalling

Answer 2

When a hormone is released into the blood stream with a distant target

Question 3

Describe autocrine signalling and give an example

Answer 3

When a cell releases a signalling molecule that acts on itself, for example neurotransmitter autoreceptors

Question 4

Describe juxtacrine signalling and give an example

Answer 4

Signalling requiring close cell to cell contact, for example gap junction between cells or T cell signalling

Question 5

Describe paracrine signalling and give an example

Answer 5

When signalling molecules are released and act on close by target cells, for example synaptic transmission between 2 neurons

Question 6

Give an model system that integrates many different cell communication methods

Answer 6

The effects of stress via glutamatergic transmission

Question 7

Give an example of how endocrine signalling influences neuronal signalling in times of stress

Answer 7

In times of stress, corticosterones are released and bind to glucocorticoid receptors on the presynaptic membranes in the frontal and pre-frontal cortex. This triggers a release of the neurotransmitter glutamate into the synaptic cleft which increases the firing of action potentials.

Question 8

Give a specific example of autocrine signalling with autoreceptors for neurotransmitters.

Answer 8

Pre-synaptic mGluRs inhibit the influx of Ca2+ into the cells which reduces the release of neurotransmitters such as glutamate

Question 9

Describe the difference between ionotropic and metabotropic signalling in the synapse

Answer 9

Ionotropic affects the ion channels and causes fast direct transmission of the action potential. But metabotropic has a slower, modulatory role (excitatory or inhibitory) that affects the G protein coupled effector cells

Question 10

Describe retrograde signalling and give an example

Answer 10

When pre synaptic receptors respond to post synaptically released signals, for example endocannabinoids are sent back to the pre synaptic membrane

Question 11

What is receptor signalling

Answer 11

When receptors in the membrane are moved laterally, removed or inserted

Question 11

Give 2 cell signalling mechanisms that can affect the strength of synaptic transmission in the long term

Answer 11

-receptor signalling
-genetic modulation of synapse transmission

Question 12

Give an example of how gene modulation of synapse transmission can affect the strength of synaptic transmission in the long term

Answer 12

It can cause the activation of Ca2+ cascades, resulting in CREB dependent transcription and protein translation. These proteins can alter long term synapse activity.

Question 13

What are the 3 post synaptic receptors involved in ionotropic glutametergic transmission

Answer 13

-AMPA
-NMDA
-Kainate

Question 14

Which glutamate signalling pathway is fast and which is slow

Answer 14

Ionotropic - fast
Metabotropic - slow

Question 15

Which glutamate signalling pathway can be excitatory or inhibitory

Answer 15

Metabotropic