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Neurotransmitter
#2 group (Ajou, Sogang Univ.)
An Bum-Chu, Lee Kyung-Bun
ACADEMYIC CONFERENCE OF LIFE SCIENCE
Content
Introduction
 Neurotransmitter



Receptor



Definition, synthesis & storage, Release, Recovery & degradation,
discovery
Receptor type (transmitter-gated ion channel, G-protein coupled
receptor)
AChR, GABAAR, Dopamine receptor, Glutamate receptor, Opioid
receptor
Neuropharmacology


Agonist and Antagonist
Cocaine & Amphetamine, Caffeine, opioid, nicotine, alcohol
Introduction
 Why
should we study neurotransmitter
about addiction?
 How
will we study neurotransmitter
about addiction?
Definition

The molecule must be synthesized and stored in
the presynaptic neuron.

The molecule must be released by the
presynaptic axon terminal upon stimulation.

The molecule, when experimentally applied,
must produce a response in the postsynaptic cell
that mimics the response produced by the
release of neurotransmitter from the
presynaptic neuron.
Classification



Amino
acid
Amine
Peptide
Major neurotransmitter
AMINO ACID
AMINE
PEPTIDE
GABA
acetylcoline
cholestokinin
glutamate
Dopamine
dynorphin
glycine
epinephrine
enkephalines
histamine
NAAG
norepinephrine
Neuropeptide Y
serotonine
somatostatin
Substance P
Thyropin-releasing
hormone
Vasoactive intestinal
polypeptide
Synthesis & Storage

Amino acid &
Amine

Peptide
Synthesis & Storage

Colinergic neuron

Catecholaminergic
neuron

Serotoninergic neuron

Amino acidergic neuron
Release

Arrival of AP

Ca2+ channel open
(voltage dependent)

Ca2+ influx

Exocytosis
(synaptic vesicle)
Recovery & Degradation
 Diffusion
 Reuptake

Presynapse transport & glia transport
 Degradation

Degradation by enzyme
acetylcolin
AChE
Acetate + choline
Discovery

Immuno cytochemistry

In situ hybridization
Receptor
 Receptor
 AChR
type
(Acetylcoline receptor)
 GABAA receptor
 Dopamine
receptor
 Glutamate
receptor
 Opioid
receptor
Receptor Type

Transmitter-gated
ion channel



IPSP (inhibitatory
postsynaptic potential)
EPSP (excitatory
postsynaptic potential)
G-protein coupled
receptor


Shortcut pathway
Second messenger cascade
(acetylcolin receptor)

nAChR




Skeletal muscle
Transmitter-gated ion
channel
4 subunit & pentamer
mAChR



Cardiac muscle
G protein-coupled
receptor
4 subtype (m1, m2, m3,
m4)
AChR
GABAA Receptor

Transmitter-gated
ion channel

Cl- ion influx
(IPSP)
Dopamine
Receptor

G-protein coupled
receptor

D1-like family
(D1, D5)

D2-like family
(D2-D2L · D2S, D3, D4)
Glutamate Receptor

AMPA, NMDA,
kainate

Transmitter-gated
ion channel

Mechanism
Opioid Receptor
 Antinociception
 G-protein
coupled receptor
 Subtype

μ (μ1·μ2),
δ(δ1·δ2),
κ(κ1·κ2·κ3)
Neuropharmacology
 Antagonist
& agonist
 Action of addictive drugs
 Coanine & amphetamine
 Caffeine
 Opioites
 Nicotine
 Alcohol
Action of addictive drugs
 drug
: imitation or inhibition of secretion of
specific neurotransmitter

antagonist
Blocking of specific neurotransmitter

agonist
Imitation or increase of neurotransmitter

The ways the drug can affect the synaptic
transmission
Action of addictive
drugs
 Dopamine-neurotransmitter

synthesis, storage, release

actions of dopamine
of CNS

Dopaminergic nigro-neostriatal pathway

Mesolimbic dopaminergic pathway

Tubo-infundidular system
 Mesolimbic
dopaminergic
reward system
Cocaine &
Amphetamine

Mechanism

Cocaine and amphetamine → binding to dopamine reuptake
trandporter → inhibition of dopamine reuptake→
accumulation of dopamine in synapse → stimulation of
receptor → incresed dopamine activity

Actions of cocaine& amphetamine : temporary

Autoreceptor

Flash (add cocaine, without cocaine)
Amphetame-powerfully dopamine releases -mentaliy,
physically

Inhibition of
dopamine reuptake
 Other
drug
ex.cocaine, amphetamine, domperidone
Caffeine
 Caffeine

action : heart rate increase, blood vessel
constriction , headache

Inhibition of adenosine
adenosine : inhibition of dopamine release
 As a result, increase of dopamine release

Opiates
 Morphine,
heroin
 endolphin: neurotransmitter released
from brain
 endolphin opiates → receptor → excite
of periaqueductal gray area → decreased
secretion of P substance → decreased
pain
 Pain
pathway
 pathway
of
analgesia
suppression
Nicotine

Chemical in cigarette

nicotinic receptor(acethycholine receptor)
blocking

Binding to receptor that increase the sectretion
of doapmine in nucleus accumbens → reinforce

Catecholamine release → rised blood pressure,
perspiration
nicotinic receptor
and its action
Alcohol

Disfunction of
recognition (inference,
memory etc)

Influx inhibition of Na+
→ prevention of nerve
system

Decrease of serotonin,
activation of GABA
receptor