Topic 8.1

Question 1

How is information encoded in the nervous system? (3)

Answer 1

1. labelled lines
2. spatial maps
3. Pattern of nerve impulses

Question 2

neural network function (3 steps)

Answer 2

1) input
2) computation
3) output

Question 3

Most frequent nt for EPSP

Answer 3

glutamate

Question 4

What are the 2 glutamate receptor types?

Answer 4

• ionotropic

- metabotropic

Question 5

Most frequent nt for IPSP

Answer 5

GABA

Question 6

GABA receptor types

Answer 6

GABA a : ligand gated Cl- channel

Gaba b : Gi coupled

Question 7

How is anion selectivity determined for GABA a?

Answer 7

Charged AA side chains inside the channel

Question 8

Analog receptors to GABAa (3)

Answer 8

1. Glycine R (anion channel)

2. nACHR, 5HT3R (cation channels)

Question 9

How is amplitude of combined PSP encoded?

Answer 9

In the AP frequency

Question 10

How is rythmic bursting activity explained?

Answer 10

Presence of VDCC + Calcium dependant K+ channel

Question 11

Types of channels in non adapting neuron?

Answer 11

• quick voltage gated Na+ channel

- K+ channel

Question 12

Type of channel in adapting neuron

Answer 12

slowly activating, voltage gated K+ channel

Question 13

Example of retrograde signaling

Answer 13

With 2-arachydonylglycerol and CB1R

Question 14

Which glutamate receptors are GQ coupled?

Answer 14

metabotropic type 1 and 5

Question 15

WHich enzyme converts DAG - 2AG

Answer 15

DAG lipase

Question 16

What type of substance is 2-AG

Answer 16

endocanabinoid

Question 17

What is synaptic plasticity?

Answer 17

If AP frequency / pattern changes, strength of connection between 2 neurons may change

Question 18

What is synaptic strength?

Answer 18

the mean amplitude of the post synaptic response (EPSP)

Question 19

4 types of synaptic strength increase

Answer 19

• facilitation
• Augmentation
• Potentiation
• Long term potentiation (LSP)

Question 20

What can synaptic strength decrease be a result of? (3)

Answer 20

• habituation
• depression
• long term depression

Question 21

Where is long term potentiation observed?

Answer 21

in the hippocampus

Question 22

Volume of brain occupied by glial cells

Answer 22

1/2 volume of the brain

Question 23

CNS glial cell types (3)

Answer 23

• Astrocytes
• Oligodendrocytes
• Microglial cells

Question 24

Types of astrocytes (6)

Answer 24

1. Fibrous
2. Protoplasmic
3. Radial glial cell
4. Müller cell
5. Bergmann glia
6. Ependymal cell

Question 25

Where are satellite cells found?

Answer 25

in sensory and autonomic ganglia

Question 26

Glial cells in the PNS (3)

Answer 26

- Satellite cells - Enteric glial cells - Schwann cells

Question 27

How can astrocytes be identified

Answer 27

By their specific intermediate filament GFAP

Question 28

Functions of astrocytes (5)

Answer 28

- Provide fuel in the form of lactate - Regulate K+ and pH of brain and ECF - Glutamate / glutamine cycle - Secrete trophic factors BDNF and GDNF - Modulate cerebral blood flow (neural activity induced vasodilation)

Question 29

2 ways for glucose to reach neuron

Answer 29

``` Direct path (glut 3) Transastrocyte path (glut1) ```

Question 30

What is MCT 1 & 2

Answer 30

Monocarboxylate transporter : lactate and H+ co transporter

Question 31

Brain ECF [K+] + during max activity

Answer 31

3mM or 2.8mM | Max activité : 12mM

Question 32

Glutamate concentration in neuron

Answer 32

10mM

Question 33

Glutamate concentration EC

Answer 33

1 microM

Question 34

Where do microglial cells derive from?

Answer 34

Monocyte macrophage lineage

Question 35

What do microglial cells release when activated?

Answer 35

They release cytokines, free radicals and NO