synaptic transmission

Question 1

Presynaptic neuron terminal –

Postsynaptic neuron –

Answer 1

Presynaptic neuron terminal – conducts impulses toward the synapse

Postsynaptic neuron – transmits impulses away from the synapse

Question 2

Electrical:
vs
Chemical:
synapse

Answer 2

Electrical: low resistance pathway between cells (gap junctions)
allows current to flow directly between cells
allows the exchange of small molecules between cells

Chemical: specialized junction where cells interact via a chemical intermediate (neurotransmitter)

Question 3

connexon

Answer 3

Pore size =1nm in diameter
(much larger than voltage-gated ion channels)
Allows the passage of :Ions, ATP. 2nd messenger molecules

Question 4

multiple __ make up gap junctions

Answer 4

connexons

Question 5

characteristics of electrical synapses

Answer 5

Fast transmission (no synaptic delay)
Bidirectional: current flows both ways
Contain sites for phosphorylation

Question 6

electrical synapses Can be modulated by

Answer 6

Can be modulated by several factors:
Voltage
pH
[Ca++]

Question 7

SNARE

Answer 7

SNARE (solubleNSFattachment proteinreceptor) protein
N-ethylmaleimide sensitive fusion proteins (NSF)

mediate vesicle transport and fusion

Question 8

vesicle vs target snare

Answer 8

synaptobrevin

t: SNAP 25 and syntaxin

Question 9

Processes taking place in Active Zone of NT release

Answer 9

docking
priming
fusion
release

Question 10

__ binds to Ca2+ and Initiates Fusion

Answer 10

Synaptotagmin

Question 11

explain docking and priming ?

Answer 11

d: Synaptic vesicle docks in active zone.
p: SNARE proteins form complexes that pull and hold membranes together

Question 12

fusion ?

Answer 12

synaptotagmin binds to Ca2+ and Initiates Fusion

Ca2+-synaptotagmin complex binds to SNAREs and imbeds into plasma membrane

Question 13

how does botox work

Answer 13

Botulinum toxin binds to and is taken up by cholinergic nerves.
Botulinum toxin exerts it’s effect by cleaving SNAREs.

Question 14

Removal of Neurotransmitters from Synaptic Cleft

Answer 14

Taken up via transporters into axon terminals or glial cells
Degraded/metabolized by enzymes
Diffuse away from synaptic cleft

Question 15

distance b/w pre and post synaptic mem in electrical vs chemical

Answer 15

e: 2-4 nm
c: 20-40 nm

Question 16

electrical vs chemical ultrastrucal components

Answer 16

w: gap junctions
c: presynaptic vesicle, active zone synaptic cleft

Question 17

postsynaptic potentials are initiated by:
triggered by :
and determined by:

Answer 17

Initiated by the binding of a neurotransmitter to its receptor on postsynaptic membrane

Triggered by opening of channels which increased membrane permeability to specific ions.

Determined by the function of the receptor type on the postsynaptic membrane

Question 18

EPSPs vs IPSPs

Answer 18

Drives the membrane potential to a value above threshold

Drives the membrane potential to a value below threshold

Question 19

Ionotropic vs metabotropic

Answer 19

Ion channels
Rapid actions

Activate 2nd messenger systems
Slow, long lasting actions

Question 20

small molecules can be iontropic or metabotropic

T/F

Answer 20

T

Question 21

Peptides can be iontopic or metabotropic

T/F

Answer 21

F only metabotropic

Question 22

Dopamine:
Norepinephrine: 
Epinephrine: 
Serotonin: 
Histamine:

Answer 22

Dopamine: Movement, Reward,  Addiction
Norepinephrine: Attention, Arousal
Epinephrine: Cognition, Attention,
Serotonin: Affective state
Histamine: Arousal, Satiety & Thirst, Pain

Question 23

Enkephalins

Answer 23

neuropeptide NT
opioids that have analgesic effects
Substance P

Question 24

__ blocks adenosine receptors

Answer 24

Caffeine blocks adenosine receptors

Question 25

Endocannabinoids

Answer 25

Endocannabinoids
Bind to receptors that also bind to THC (cannabis)
Modulates synaptic plasticity

Question 26

Nitric Oxide

Answer 26

Nitric Oxide
A gas produced from amino acid Arginine
Vasodilator affected by the drug Viagara