Neuro 2 Role of Neurones and Glia Flashcards Preview

ESA 5 > Neuro 2 Role of Neurones and Glia > Flashcards

Flashcards in Neuro 2 Role of Neurones and Glia Deck (31):
1

What are the 3 types of glial cells?

  1. Astrocytes
  2. Oligodendrocytes
  3. Microglia

2

What is the 5 roles of astrocytes?

  • Structural support
  • Helps Provides nutrition
  • Remove neurotransmitters
  • Maintain ionic environment by K+ buffering
  • Help form BBB

3

How do astrocytes help provide energy for neurones?

Astrocytes produce lactate which is transferred to neurones to supplement their supply of glucose

4

How do astrocytes help to remove neurotransmitters? Why is this necessary?

Re-uptake of transmitters

Prevents excitation of neaby neurons and prevents formation of another EPSP

5

How do astrocytes help to buffer K+ in brain ECF?

K+ excreted from neurones into ECF and then can be taken up via Na+K+ATPase, K+ channel, or Na-K-Cl cotransporter of astrocyte

6

What is the function of oligodendrocytes?

Myelinate axons in CNS

7

What cell type myelinates axons in the PNS?

Schwann cells

8

What is the function of microglia? What germ layer is microglia derived from?

  • Immune cells
  • phagocytose debris and foreign material
  • Derived from mesoderm

9

How is the BBB formed?

Formed by the brain capillaries having tight junctions between endothelial cells, and the end feet of astrocyte processes surrounding the BV

10

Whta are the 3 chemical classes of neurotransmitter in the CNS?

Amino acids

Biogenic amines

Peptides

11

What are the excitatory and inhibitory AA neurotransmitters?

Excitatory - Glutamate

Inhibitory - GABA and glycine

12

What are the ionotropic and metabotropic glutamate receptors? What are they permeable to?

Ionotropic:

  • AMPA - Na and K
  • Kainate - Na and K
  • NMDA - NA, K, and Ca

Metabotropic:

  • mGluR1-7

13

What is the co-agnosist of NMDA receptors?

glycine

14

How is long term potentiation achieved? What can go wrong?

NMDA receptors activated through strong, high frequency stimulation results in calcium entry into cell and up-regulation of AMPA receptors and easier depolarisation in the future.

Too much calcium however causes excitotoxicity

15

Of the inhibitory AAs, which is found primarily in the brain and which is mostly in th ebrainstem and spinal cord?

Brain - GABA

Brainstem and spinal cord - Glycine

16

How does GABA and glycine receptors cause hyperpolarisation of a cell?

GABA and glycine receptors have integral Cl- channels that hyperpolarise

17

What is the mechanism of action of barbiturates and benzodiazepines?

Both enhance the response to GABA and therefore have sedative and anxiolytic effects.

18

Explain how the patellar tendon reflex arc works

Hitting the patellar tendon results in activation of a sensory neuron in the quadriceps muscle which sends a signal to an excitatory motor synapse in the quadriceps and an inhibitory interneuron that connects to the hamstring muscle

19

What are the main areas of action of ACh?

  • Neuromuscular junction
  • ganglion synapse in ANS
  • postganglionic parasympathetic
  • CNS neurotransmitter at nicotinic and muscarinic receptors in brain

20

What are cholinergic pathways in the CNS linked to?

Arousal, learning & memory, motor control

21

What is the cause of Alzheimer's disease?  How is AD treated?

degeneration of cholinergic neurones in the nucleus basalis. treated with cholinesterase inhibitors

22

Name the 4 dopaminergic pathways in the CNS and what they are involved in

Nigrostriatal pathway - motor control

Mesocotrical and mesolimbic pathway - mood, arousal, and reward

tubero-hypophyseal pathway 

23

What is PD associated with and how can it be treated?

Parkinsons associated with loss of dopaminergic neurons

Treated with levodopa (L-DOPA) which is converted to dopamine by AADC. However, you dont want dopamine to be produced outside of the brain so levodopa is coupled with carbidopa to inhibit AADC and the production of dopamine outside brain. Since carbidopa and AADC cant cross the BBB the LNAA (large neutral amino acid transporter) takes L-DOPA across the BBB and the AADC in the brain converts it to Dopamine

24

What is schizophrenia a disorder of and how can it be treated?

Possibly due to too much dopamine production and therefore antagonists of dopamine D2 receptors are given

25

Where can NA be found?

postganglionic sympathetic and neurotransmitter in CNS

26

What receptors does NA act through?

GPCR alpha and beta adrenoreceptors

27

Which group of neurons in the brain does most NA in the brain come from? What is their function?

Locus ceruleus - nucleus in pons

Function - arousal and wakefulness.

28

What is serotonin AKA?

5-HT

29

How do tricyclic antidepressants function?

Inhibit uptake of NA/5-HT

30

How do SSRIs work? What do they treat?

Treat depression and anxiety by inhibiting serotonin reuptake

31

What is a MAOI and how does it work?

Monoamine oxidase inhibitor

MAO metabolises monoamines and therefore MAOI inhibits this breakdown