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Flashcards in The Synapse Deck (28):
1

What is the soma of a neuron

Synthetic and metabolic centre
Contain nucleus, ribosomes, mito, ER
Integrate incoming signals that are conducted passively to axon hillock

2

What is the axon hillock

Site of initiation of the all or none AP

3

What is an axon

Conducts out out signals as APs to other neurones
Mediated transport of materials between soma and presynaptic terminal

4

What is a synapse

Point of chemical communication between neurones

5

What are key structural elements of the chem synapse

Pre and post synaptic mems sep by a narrow synaptic cleft
Matrix of fibrous extracellular protein in cleft that hold pre and post syn mems together
Vesicles in presynaptic terminal that store neurotransmitter
Mem differentiations - preysnaptically active zones around vesicles cluster
- postsyn contains neurotransmitter receps

6

What are the classifications of synapses

Gary's type 1. - asymmetrical syn which mems differentiation on postsyn side is thicker than on presyn side
Excitatory

Grays you 2 - symmetrical synapses which mem differentiations are. Of similar thickness
Inhibitory

7

What are some types of synapse

Classed morphologicalky byy location of presyn terminal on postsyn cell

Axodendritic - axon to dendrite very common

Axosomatic - axon to soma common

Axoaxonic - axon to axon uncommon

8

What are the functional types of synapse

Excitatory - cns the transmitter is glutamate which activates postsyn cation, ionotropic glutamate receps which gen a local excitatory depo effect - excitatory postsyn potential


Inhibitory - cns transmitter GABA or glycine, activates postsyn anion receps gen a local inhib effect hyperporlarising - inhibitory postsyn potentail

9

What are the major amino acid neurotransmitters in the cns

Glutamate
GABA
Glycine

10

What is spatial summation

Many inputs converge upon a neurone to determine its output

11

What is a temporal summation

A single input may modulate output by variation in AP frequency of that input

12

What are temporal and spatial summations

Not isolated but are complementary processes

13

What are amino acid and amine neurotransmitters released form

Synaptic vesicles

14

What are peptide neurotransmitters released from

Secretory vesciles

15

What activates ionotropic ligand-gated ion channels

Glutamate
GABA
Glycine
ACh
5-HT

16

All but 'what' can activate metabotrophic GPCR's

Glycine

17

What are some amine neurotransmitters

ACh
Dopamine
Histamine
Noradrenaline
Serotonin

18

What are some peptide neurotransmitters

Cck
Somatostatin
TRH

19

Give an overview of neurochemical transmission

Intake precursor
Syn transmitter
Store transmitter
Depo by AP
Calcium influx through voltage activated calcium channels
Calcium induced release of transmitter
Receptor activation
Enzyme mediated inactivation of transmitter
Reuptake of transmitter

20

Glycine and glutamate occur in

All cells not just neurones

21

GABA and amines must be

Specially syn by neurones with specific enzymes

22

Where are the specific enzymes used for gaba and amine production produced and what do they do

Syn in cell body and trans to presyn terminal by axoplasmic transport

At terminal enzymes mediate syn within cyto of neurotrans form precursor subs

23

What concentrates neurotransmitters

Conc in vesicles by transporters embedded in vesicle mem

24

What is the syn and storage of neurotransmitters

Syn of precursor peptide by ribosomes at ER

Cleavage of precursor peptide in Golgi apparatus yielding active neurotransmitters

Sec granules bud off from the Golgi apparatus

Sec granules are trans to presyn terminal by fast axoplasmic trans

25

What are the key features of the exocytosis of amino acid and amine neurotransmitters

Synaptic vesciles ready for rapid release are held in apposition to presyn mem in docking SNARE complex

Depo fo presyn mem opens voltage activated calcium channels causing a rise in conc of calcium in vicinity of docked vesciles

Calcium binds to synaptotagmin-1 ion vesicle mem causing vesicle to fuse to presyn mem

Neurotransmitter diffuses from vesicle to cleft

Mem added to presyn terminal and retrieved by endocytosis

26

What are ligand gated ion channels

Aka, ionotropic receps

Consist of sep glycoproteins that form central, ion conducting, channel

Allow rapid change in perm of mem to certain ions

Rapidly alter mem potentail

27

What are GPCR's

Aka metabotrophic receps

Receptor, G protein and enzyme sep

G protien couples receptor activation to effector modulation

Signalling via G proteins relatively slow in comparison to ligand gated ion channels

28

What are dendrites

Recieve inputs from other neurones and convey graded electrical signals passively to the soma