Neurotransmitter
description
Transcript of Neurotransmitter
Neurotransmitter
#2 group (Ajou, Sogang Univ.)
ACADEMYIC CONFERENCE OF LIFE SCIENCE
An Bum-Chu, Lee Kyung-Bun
Content Introduction Neurotransmitter
Definition, synthesis & storage, Release, Recovery & degradation, discovery
Receptor 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
cholestokininacetylcolineGABA
dynorphinDopamineglutamate
enkephalinesepinephrineglycine
NAAGhistamine
Neuropeptide Ynorepinephrine
somatostatinserotonine
Substance PThyropin-releasing
hormoneVasoactive intestinal
polypeptide
Major neurotransmitterPEPTIDEAMINEAMINO ACID
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
Acetate + choline
AChE
Discovery Immuno -
cytochemistry
In situ hybridization
Receptor Receptor type
AChR (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) AChR nAChR
Skeletal muscle Transmitter-gated ion
channel 4 subunit & pentamer
mAChR Cardiac muscle G protein-coupled
receptor 4 subtype (m1, m2, m3,
m4)
Transmitter-gated ion channel
Cl- ion influx (IPSP)
GABAA Receptor
G-protein coupled receptor
D1-like family (D1, D5)
D2-like family (D2-D2L · D2S, D3, D4)
Dopamine Receptor
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 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 of CNS
synthesis, storage, release
actions of dopamine 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