S6 Neuro Neurotransmitters and synaptic transmission

Question 1

Gap Junction characteristics

Answer 1

small: 3.0-3.5 nm gap between membranes

cytoplasms connect when channels open

fast (

Question 2

chemical synapse characteristics

Answer 2

Characteristics

1. ) 20-50 nm gap between membranes
2. ) No cytoplasmic continuity
3. ) Slower (~2 msec)
4. ) More common

Question 3

Key proteins involved in synaptic vesicle fusion

Answer 3

SNAREs and Vesicle trafficking:

• SNAREs: SNAP REceptors
• SNAP: Soluble NSF Attachment Protein

Question 4

which of the proteins in the synaptic vesicle is the calcium sensor

Answer 4

snaptotagmin

Question 5

T-snares of interest in synaptic vesicle

Answer 5

syntaxin

SNAP-25

Question 6

V-snare of NT containing vesicle

Answer 6

snaptobrevin

Question 7

Synaptic vesicle recycling

Answer 7

Fused vesicle->

clathrin coated->

Dynamic helps pinch vesicle from nerve terminal->

ATPase-> removes clathrin

synopsis binds to cytoskeleton help pull it away from nerve terminal.

Question 8

other means of synaptic vesicle recycling

Answer 8

endosmoal intermediate

kiss and run

Question 9

Major classes of neurotransmitters

Answer 9

small-molecule neurotransmitters

neuropeptide

gaseous neurotransmitters

Question 10

Small molecule NTs

Answer 10

acetylcholine
excitatory AA: glutamate

Inhibitory AA: GABA, Glycine

Biogenic Amines- Catecholamines:

1. dompamine
2. norepinephrine
   3: epinephrine

Indoleamine: Serotonin (5-HT)

imadazole amine: histamine

purine: adenosine

Question 11

Acetylcholine synthesized in

Answer 11

cytoplasm. by conversion of choline to acetylcholine. packaged into vesicle

Question 12

Acetylcholine breakdown occurs

Answer 12

in synapse. choline product is recycled into neuron

Question 13

one of the acetylcholine rich sites in brain

Answer 13

nucleus of meynert

Question 14

Deficits of acetylcholine in Nucleus of meanest associated with

Answer 14

alzheimer’s disease

Question 15

boost synaptic acetylcholine to treat AD by

Answer 15

inhibiting enzyme that breaks it down (acetylcholinesterase)

Question 16

Glutmate can be recycled via

Answer 16

glutmate transporters (reuptake) and it can be scavenged by glia

Question 17

glia will scavenge glutamate and then

Answer 17

convert it to glutamine

Question 18

glutmate is

Answer 18

excitatory. as is aspartate

Question 19

glutamate foci of synthesis

Answer 19

ubiquitous. not specific foci

Question 20

GABA can be recycled

Answer 20

via GABA transporters (reuptake)

scavenged by glia

Question 21

GABA in the glia

Answer 21

modified to glutamine and released and then took back up into neuron

Question 22

GABA is

Answer 22

inhibitory (as is glycine)

Question 23

GABA foci of synthesis

Answer 23

ubiquitous. no specific foci of synthesis.

Question 24

Catecholamines

Answer 24

3:

dopamine, norepinephrine and epinephrine

Question 25

Catecholamines are derived from

Answer 25

tyrosine

Question 26

rate limiting enzyme in catecholamine synthesis

Answer 26

tyrosine hydroxylase

Question 27

Catecholamine synthesis path

Answer 27

dopamine-> NE (via DBH) to Epi (via PNMT)

Question 28

dopamine synthesis site

Answer 28

cytoplasm

Question 29

NE synthesis site

Answer 29

in vesicle (because DBH is bound to intravesicular membrane)

Question 30

Epinephrine synthesis site

Answer 30

in cytoplasm. NE leaks out of vesicle and into cytoplasm where PNMT converts it to Epi

Question 31

catecholamine reuptake

Answer 31

each has own transporter for reuptake. no glial involement

Question 32

reuptaken catecholamines

Answer 32

are repackaged into vesicles or degraded by MAO (monoamine oxidase) or catechol-O-methyltransferase (COMT)

Question 33

High levels of DA found in its 4major pathways

Answer 33

Nigrostriatal (loss of DA Neurons linked to Parkinson's disease) Mesocortical Mesolimbic (significant component of the Reward Pathway) Tuberoinfundibular

Question 34

High levels of NE are found in the

Answer 34

locus coeruleus (in pons)

Question 35

Serotonin derived from

Answer 35

tryptophan

Question 36

rate limiting enzyme in serotonin synthesis

Answer 36

tryptophan hydroxylase

Question 37

serotonin pathways emanate from

Answer 37

raphe nuclei

Question 38

serotonin synthesis occurs in

Answer 38

the cytoplasm

Question 39

serotonin is packaged into vesicles via

Answer 39

a transporter

Question 40

serotonin reuptake

Answer 40

by serotonin transporter.

Question 41

Neuropeptides comprised of

Answer 41

opioid peptides (primarily B-endoprhin and enkephalins) and Substance P.

Question 42

Neuropeptides mature..

Answer 42

as they migrate to terminal. start out as pre-propeptides that are converted to propeptides, then the final mature NTs

Question 43

Neuropeptide reuptake

Answer 43

doesn't happen. primarily degraded by peptidases.

Question 44

NO

Answer 44

Not stored in vesicles.  Not released in a calcium dependent manner.  Does not have a specific target (not like a classical NT does, which, when released from a neuron, has the ultimate destination of the postsynaptic cell, although the NT can also affect receptors on the cell from which it was released [these are called autoreceptors, something we did not discuss]).  Released from postsynaptic cell. It can exert effects within the cell where it’s made and/or it can diffuse and affect neighboring neurons, glia, etc. Migrates by diffusion. It is a retrograde messenger if it diffuses back to the pre-synaptic cell and affects the release of NT from that cell.  Affects nearby cells via cGMP coupled mechanisms.  Has role in vasodilation and memory.

Question 45

Ach receptors

Answer 45

nicotinic (inotropic): Na in, K out | muscarinic: leads to Cl in, K out (hyper polarization)

Question 46

Glutamate receptors

Answer 46

NMDA (ionotropic) Kainate inotropic and AMPA (ionotropic): Na, in, K out mGluR (metabotropic): modulate other receptors

Question 47

Glutmate NMDA receptor

Answer 47

Calcium and NA in; K out Glutamate binding site: glumatate must bind glucose binding site: glycol must bind Magnesium binding site (Mg must be displaced for Channel to open. for this to happen cell cannot be at resting or at hyper polarized membrane potential- must be sufficient depolarized)

Question 48

GABA receptors

Answer 48

GABAa (ionotropic): chloride in - GABA binding site: GABA must bind - benzodiazepine binding site: inc frequency of opening - Barbiturate binding site: inc Duration of opening GABAb (metabotropic)

Question 49

Glycine receptor

Answer 49

ionotoropic: chloride in

Question 50

Dopamine receptor

Answer 50

metabotropic

Question 51

Adnergic receptor

Answer 51

metabotropic. make neurons more excitable